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Sample records for black warrior paradox

  1. Reservoir heterogeneity in carboniferous sandstone of the Black Warrior basin. Final report

    SciTech Connect (OSTI)

    Kugler, R.L.; Pashin, J.C.; Carroll, R.E.; Irvin, G.D.; Moore, H.E.

    1994-06-01

    Although oil production in the Black Warrior basin of Alabama is declining, additional oil may be produced through improved recovery strategies, such as waterflooding, chemical injection, strategic well placement, and infill drilling. High-quality characterization of reservoirs in the Black Warrior basin is necessary to utilize advanced technology to recover additional oil and to avoid premature abandonment of fields. This report documents controls on the distribution and producibility of oil from heterogeneous Carboniferous reservoirs in the Black Warrior basin of Alabama. The first part of the report summarizes the structural and depositional evolution of the Black Warrior basin and establishes the geochemical characteristics of hydrocarbon source rocks and oil in the basin. This second part characterizes facies heterogeneity and petrologic and petrophysical properties of Carter and Millerella sandstone reservoirs. This is followed by a summary of oil production in the Black Warrior basin and an evaluation of seven improved-recovery projects in Alabama. In the final part, controls on the producibility of oil from sandstone reservoirs are discussed in terms of a scale-dependent heterogeneity classification.

  2. Reservoir heterogeneity in Carboniferous sandstone of the Black Warrior basin. Final report

    SciTech Connect (OSTI)

    Kugler, R.L.; Pashin, J.C.; Carroll, R.E.; Irvin, G.D.; Moore, H.E.

    1994-04-01

    Although oil production in the Black Warrior basin of Alabama is declining, additional oil may be produced through improved recovery strategies, such as waterflooding, chemical injection, strategic well placement, and infill drilling. High-quality characterization of reservoirs in the Black Warrior basin is necessary to utilize advanced technology to recover additional oil and to avoid premature abandonment of fields. This report documents controls on the distribution and producibility of oil from heterogeneous Carboniferous reservoirs in the Black Warrior basin of Alabama. The first part of the report summarizes the structural and depositional evolution of the Black Warrior basin and establishes the geochemical characteristics of hydrocarbon source rocks and oil in the basin. This second part characterizes facies heterogeneity and petrologic and petrophysical properties of Carter and Millerella sandstone reservoirs. This is followed by a summary of oil production in the Black Warrior basin and an evaluation of seven improved-recovery projects in Alabama. In the final part, controls on the producibility of oil from sandstone reservoirs are discussed in terms of a scale-dependent heterogeneity classification.

  3. Feasibility study of heavy oil recovery in the Appalachian, Black Warrior, Illinois, and Michigan basins

    SciTech Connect (OSTI)

    Olsen, D.K.; Rawn-Schatzinger, V.; Ramzel, E.B.

    1992-07-01

    This report is one of a series of publications assessing the feasibility of increasing domestic heavy oil production. Each report covers select areas of the United States. The Appalachian, Black Warrior, Illinois, and Michigan basins cover most of the depositional basins in the Midwest and Eastern United States. These basins produce sweet, paraffinic light oil and are considered minor heavy oil (10{degrees} to 20{degrees} API gravity or 100 to 100,000 cP viscosity) producers. Heavy oil occurs in both carbonate and sandstone reservoirs of Paleozoic Age along the perimeters of the basins in the same sediments where light oil occurs. The oil is heavy because escape of light ends, water washing of the oil, and biodegradation of the oil have occurred over million of years. The Appalachian, Black Warrior, Illinois, and Michigan basins' heavy oil fields have produced some 450,000 bbl of heavy oil of an estimated 14,000,000 bbl originally in place. The basins have been long-term, major light-oil-producing areas and are served by an extensive pipeline network connected to refineries designed to process light sweet and with few exceptions limited volumes of sour or heavy crude oils. Since the light oil is principally paraffinic, it commands a higher price than the asphaltic heavy crude oils of California. The heavy oil that is refined in the Midwest and Eastern US is imported and refined at select refineries. Imports of crude of all grades accounts for 37 to >95% of the oil refined in these areas. Because of the nature of the resource, the Appalachian, Black Warrior, Illinois and Michigan basins are not expected to become major heavy oil producing areas. The crude oil collection system will continue to degrade as light oil production declines. The demand for crude oil will increase pipeline and tanker transport of imported crude to select large refineries to meet the areas' liquid fuels needs.

  4. Feasibility study of heavy oil recovery in the Appalachian, Black Warrior, Illinois, and Michigan basins

    SciTech Connect (OSTI)

    Olsen, D.K.; Rawn-Schatzinger, V.; Ramzel, E.B.

    1992-07-01

    This report is one of a series of publications assessing the feasibility of increasing domestic heavy oil production. Each report covers select areas of the United States. The Appalachian, Black Warrior, Illinois, and Michigan basins cover most of the depositional basins in the Midwest and Eastern United States. These basins produce sweet, paraffinic light oil and are considered minor heavy oil (10{degrees} to 20{degrees} API gravity or 100 to 100,000 cP viscosity) producers. Heavy oil occurs in both carbonate and sandstone reservoirs of Paleozoic Age along the perimeters of the basins in the same sediments where light oil occurs. The oil is heavy because escape of light ends, water washing of the oil, and biodegradation of the oil have occurred over million of years. The Appalachian, Black Warrior, Illinois, and Michigan basins` heavy oil fields have produced some 450,000 bbl of heavy oil of an estimated 14,000,000 bbl originally in place. The basins have been long-term, major light-oil-producing areas and are served by an extensive pipeline network connected to refineries designed to process light sweet and with few exceptions limited volumes of sour or heavy crude oils. Since the light oil is principally paraffinic, it commands a higher price than the asphaltic heavy crude oils of California. The heavy oil that is refined in the Midwest and Eastern US is imported and refined at select refineries. Imports of crude of all grades accounts for 37 to >95% of the oil refined in these areas. Because of the nature of the resource, the Appalachian, Black Warrior, Illinois and Michigan basins are not expected to become major heavy oil producing areas. The crude oil collection system will continue to degrade as light oil production declines. The demand for crude oil will increase pipeline and tanker transport of imported crude to select large refineries to meet the areas` liquid fuels needs.

  5. Slim Holes At Black Warrior Area (DOE GTP) | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmental Jump to:EA EIS ReportEurope GmbH Jump to:Idaho-UtahSkyline HighBlack Warrior Area

  6. Potential for CO2 Sequestration and Enhanced Coalbed Methane Production, Blue Creek Field, NW Black Warrior Basin, Alabama 

    E-Print Network [OSTI]

    He, Ting

    2011-02-22

    and enhanced coalbed methane production in San Juan and Alberta basins, but reservoir modeling is needed to assess the potential of the Black Warrior basin. Alabama ranks 9th nationally in CO2 emissions from power plants; two electricity generation plants...

  7. Black Warrior Elec Member Corp | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmental JumpInformationBio-Gas Technologies, LLCMichigan:Earth, Wisconsin:BlackIIIBlack

  8. GEOLOGIC SCREENING CRITERIA FOR SEQUESTRATION OF CO2 IN COAL: QUANTIFYING POTENTIAL OF THE BLACK WARRIOR COALBED METHANE FAIRWAY, ALABAMA

    SciTech Connect (OSTI)

    Jack C. Pashin; Richard E. Carroll; Richard H. Groshong Jr.; Dorothy E. Raymond; Marcella McIntyre; J. Wayne Payton

    2004-01-01

    Sequestration of CO{sub 2} in coal has potential benefits for reducing greenhouse gas emissions from the highly industrialized Carboniferous coal basins of North America and Europe and for enhancing coalbed methane recovery. Hence, enhanced coalbed methane recovery operations provide a basis for a market-based environmental solution in which the cost of sequestration is offset by the production and sale of natural gas. The Black Warrior foreland basin of west-central Alabama contains the only mature coalbed methane production fairway in eastern North America, and data from this basin provide an excellent basis for quantifying the carbon sequestration potential of coal and for identifying the geologic screening criteria required to select sites for the demonstration and commercialization of carbon sequestration technology. Coalbed methane reservoirs in the upper Pottsville Formation of the Black Warrior basin are extremely heterogeneous, and this heterogeneity must be considered to screen areas for the application of CO{sub 2} sequestration and enhanced coalbed methane recovery technology. Major screening factors include stratigraphy, geologic structure, geothermics, hydrogeology, coal quality, sorption capacity, technology, and infrastructure. Applying the screening model to the Black Warrior basin indicates that geologic structure, water chemistry, and the distribution of coal mines and reserves are the principal determinants of where CO{sub 2} can be sequestered. By comparison, coal thickness, temperature-pressure conditions, and coal quality are the key determinants of sequestration capacity and unswept coalbed methane resources. Results of this investigation indicate that the potential for CO{sub 2} sequestration and enhanced coalbed methane recovery in the Black Warrior basin is substantial and can result in significant reduction of greenhouse gas emissions while increasing natural gas reserves. Coal-fired power plants serving the Black Warrior basin in Alabama emit approximately 31 MMst (2.4 Tcf) of CO{sub 2} annually. The total sequestration capacity of the Black Warrior coalbed methane fairway at 350 psi is about 189 MMst (14.9 Tcf), which is equivalent to 6.1 years of greenhouse gas emissions from the coal-fired power plants. Applying the geologic screening model indicates that significant parts of the coalbed methane fairway are not accessible because of fault zones, coal mines, coal reserves, and formation water with TDS content less than 3,000 mg/L. Excluding these areas leaves a sequestration potential of 60 MMst (4.7 Tcf), which is equivalent to 1.9 years of emissions. Therefore, if about10 percent of the flue gas stream from nearby power plants is dedicated to enhanced coalbed methane recovery, a meaningful reduction of CO{sub 2} emissions can be realized for nearly two decades. If the fresh-water restriction were removed for the purposes of CO{sub 2} sequestration, an additional 10 MMst (0.9 Tcf) of CO{sub 2} could feasibly be sequestered. The amount of unswept coalbed methane in the fairway is estimated to be 1.49 Tcf at a pressure of 50 psi. Applying the screening model results in an accessible unswept gas resource of 0.44 Tcf. Removal of the fresh-water restriction would elevate this number to 0.57 Tcf. If a recovery factor of 80 percent can be realized, then enhanced recovery activities can result in an 18 percent expansion of coalbed methane reserves in the Black Warrior basin.

  9. Water Management Strategies for Improved Coalbed Methane Production in the Black Warrior Basin

    SciTech Connect (OSTI)

    Pashin, Jack; McIntyre-Redden, Marcella; Mann, Steven; Merkel, David

    2013-10-31

    The modern coalbed methane industry was born in the Black Warrior Basin of Alabama and has to date produced more than 2.6 trillion cubic feet of gas and 1.6 billion barrels of water. The coalbed gas industry in this area is dependent on instream disposal of co-produced water, which ranges from nearly potable sodium-bicarbonate water to hypersaline sodium-chloride water. This study employed diverse analytical methods to characterize water chemistry in light of the regional geologic framework and to evaluate the full range of water management options for the Black Warrior coalbed methane industry. Results reveal strong interrelationships among regional geology, water chemistry, and gas chemistry. Coalbed methane is produced from multiple coal seams in Pennsylvanian-age strata of the Pottsville Coal Interval, in which water chemistry is influenced by a structurally controlled meteoric recharge area along the southeastern margin of the basin. The most important constituents of concern in the produced water include chlorides, ammonia compounds, and organic substances. Regional mapping and statistical analysis indicate that the concentrations of most ionic compounds, metallic substances, and nonmetallic substances correlate with total dissolved solids and chlorides. Gas is effectively produced at pipeline quality, and the only significant impurity is N{sub 2}. Geochemical analysis indicates that the gas is of mixed thermogenic-biogenic origin. Stable isotopic analysis of produced gas and calcite vein fills indicates that widespread late-stage microbial methanogenesis occurred primarily along a CO{sub 2} reduction metabolic pathway. Organic compounds in the produced water appear to have helped sustain microbial communities. Ammonia and ammonium levels increase with total dissolved solids content and appear to have played a role in late-stage microbial methanogenesis and the generation of N{sub 2}. Gas production tends to decline exponentially, whereas water production tends to decline hyperbolically. Hyperbolic decline indicates that water volume is of greatest concern early in the life of a coalbed methane project. Regional mapping indicates that gas production is controlled primarily by the ability to depressurize permeable coal seams that are natively within the steep part of the adsorption isotherm. Water production is greatest within the freshwater intrusion and below thick Cretaceous cover strata and is least in areas of underpressure. Water management strategies include instream disposal, which can be applied effectively in most parts of the basin. Deep disposal may be applicable locally, particularly where high salinity limits the ability to dispose into streams. Artificial wetlands show promise for the management of saline water, especially where the reservoir yield is limited. Beneficial use options include municipal water supply, agricultural use, and industrial use. The water may be of use to an inland shrimp farming industry, which is active around the southwestern coalbed methane fields. The best opportunities for beneficial use are reuse of water by the coalbed methane industry for drilling and hydraulic fracturing. This research has further highlighted opportunities for additional research on treatment efficiency, the origin of nitrogen compounds, organic geochemistry, biogenic gas generation, flow modeling, and computer simulation. Results of this study are being disseminated through a vigorous technology transfer program that includes web resources, numerous presentations to stakeholders, and a variety of technical publications.

  10. Adsorption Kinetics of CO2, CH4, and their Equimolar Mixture on Coal from the Black Warrior Basin, West-Central Alabama

    SciTech Connect (OSTI)

    Gruszkiewicz, Miroslaw {Mirek} S [ORNL; Naney, Michael {Mike} T [ORNL; Blencoe, James {Jim} G [ORNL; Cole, David R [ORNL; Pashin, Jack C. [Geological Survey of Alabama; Carroll, Richard E. [Geological Survey of Alabama

    2009-01-01

    Laboratory experiments were conducted to investigate the adsorption kinetic behavior of pure and mixed gases (CO2, CH4, approximately equimolar CO2 + CH4 mixtures, and He) on a coal sample obtained from the Black Warrior Basin at the Littleton Mine (Twin Pine Coal Company), Jefferson County, west-central Alabama. The sample was from the Mary Lee coal zone of the Pottsville Formation (Lower Pennsylvanian). Experiments with three size fractions (45-150 m, 1-2 mm, and 5-10 mm) of crushed coal were performed at 40 C and 35 C over a pressure range of 1.4 6.9 MPa to simulate coalbed methane reservoir conditions in the Black Warrior Basin and provide data relevant for enhanced coalbed methane recovery operations. The following key observations were made: (1) CO2 adsorption on both dry and water-saturated coal is much more rapid than CH4 adsorption; (2) water saturation decreases the rates of CO2 and CH4 adsorption on coal surfaces, but it appears to have minimal effects on the final magnitude of CO2 or CH4 adsorption if the coal is not previously exposed to CO2; (3) retention of adsorbed CO2 on coal surfaces is significant even with extreme pressure cycling; and (4) adsorption is significantly faster for the 45-150 m size fraction compared to the two coarser fractions.

  11. Gas Flux Sampling At Black Warrior Area (DOE GTP) | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QAsource History View New PagesSustainable UrbanKentucky: Energy Resources JumpGarfieldGarvin County,Evans,4)Black

  12. Gas Sampling At Black Warrior Area (DOE GTP) | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QAsource History View New PagesSustainable UrbanKentucky: Energy ResourcesMaui Area (DOE GTP)EnergyWith GasesBlack

  13. Cuttings Analysis At Black Warrior Area (DOE GTP) | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX ECoopButtePower VenturesInformation9) Wind Farm JumpAlum Area (DOE GTP) JumpBlack

  14. Site Characterization for CO{sub 2} Storage from Coal-fired Power Facilities in the Black Warrior Basin of Alabama

    SciTech Connect (OSTI)

    Clark, Peter; Pashin, Jack; Carlson, Eric; Goodliffe, Andrew; McIntyre-Redden, Marcella; Mann, Steven; Thompson, Mason

    2012-08-31

    Coal-fired power plants produce large quantities of carbon dioxide. In order to mitigate the greenhouse gas emissions from these power plants, it is necessary to separate and store the carbon dioxide. Saline formations provide a potential sink for carbon dioxide and delineating the capacity of the various known saline formations is a key part of building a storage inventory. As part of this effort, a project was undertaken to access the storage capacity of saline reservoirs in the Black Warrior Basin of Alabama. This basin has been a productive oil and gas reservoir that is well characterized to the west of the two major coal-fired power plants that are north of Birmingham. The saline zones were thought to extend as far east as the Sequatchie Anticline which is just east of the power plants. There is no oil or gas production in the area surrounding the power plants so little is known about the formations in that area. A geologic characterization well was drilled on the Gorgas Power Plant site, which is the farthest west of two power plants in the area. The well was planned to be drilled to approximately 8,000 feet, but drilling was halted at approximately 5,000 feet when a prolific freshwater zone was penetrated. During drilling, a complete set of cores through all of the potential injection zones and the seals above these zones were acquired. A complete set of openhole logs were run along with a vertical seismic profile (VSP). Before drilling started two approximately perpendicular seismic lines were run and later correlated with the VSP. While the zones that were expected were found at approximately the predicted depths, the zones that are typically saline through the reservoir were found to be saturated with a light crude oil. Unfortunately, both the porosity and permeability of these zones were small enough that no meaningful hydrocarbon production would be expected even with carbon dioxide flooding. iv While this part of the basin was found to be unsuitable for carbon dioxide injection, there is still a large storage capacity in the basin to the west of the power plants. It will, however, require pipeline construction to transport the carbon dioxide to the injection sites.

  15. The Firewall Paradox

    E-Print Network [OSTI]

    Furkan Semih Dündar

    2014-11-20

    In this MSc. thesis, we have attempted to give an overview of the firewall paradox and various approaches towards its resolution. After an introductory chapter on some basic concepts in quantum field theory in curved spacetimes such as Hawking radiation, we introduce the paradox. It arises out of application of principles each of which is thought or assumed to be correct: 1) unitary black hole evaporation, 2) validity of quantum field theory in curved spacetime, 3) a measure of the number of black hole quantum states, 4) Einstein's equivalence principle. Then, we present various approaches that exist in the literature towards the resolution of the paradox.

  16. Quantum Information Cannot Be Completely Hidden in Correlations: Implications for the Black-Hole Information Paradox

    E-Print Network [OSTI]

    Braunstein, Samuel L.

    5DD, United Kingdom 2 Institute of Physics, Sainik School Post, Bhubaneswar-751005, Orissa, India, this classical result has fueled the conjecture that while black-hole information cannot strictly be found within whose details are unknown to her. In addition, she shares one-half of an entangled state with Bob. Alice

  17. Black Warrior Geothermal Area | Open Energy Information

    Open Energy Info (EERE)

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  18. Black Warrior Geothermal Area | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmental JumpInformationBio-Gas Technologies, LLCMichigan:Earth,

  19. File:EIA-BlackWarrior-BOE.pdf | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QAsource History View New Pages Recent Changes AllApschem.pdf Jump to:ColoradoBOE.pdf Jump to:BOE.pdf

  20. File:EIA-BlackWarrior-GAS.pdf | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QAsource History View New Pages Recent Changes AllApschem.pdf Jump to:ColoradoBOE.pdf Jump to:BOE.pdfGAS.pdf Jump

  1. File:EIA-BlackWarrior-LIQ.pdf | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QAsource History View New Pages Recent Changes AllApschem.pdf Jump to:ColoradoBOE.pdf Jump to:BOE.pdfGAS.pdf

  2. Black Warrior, Nevada: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX ECoop IncIowaWisconsin:Pontiac Biomass Facility JumpII Jump to:BitworksFarm

  3. San Juan Montana Thrust Belt WY Thrust Belt Black Warrior

    Gasoline and Diesel Fuel Update (EIA)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustments (Billion Cubic Feet) Wyoming963 1.969 1.979 1.988 1.996 2.003 1990-2016November 2000 Overview OilSan

  4. The First Measurement of Spectral Lines in a Short-Period Star Bound to the Galaxy's Central Black Hole A Paradox of Youth

    E-Print Network [OSTI]

    Ghez, A M; Matthews, K; Hornstein, S D; Tanner, A; Larkin, J; Morris, M; Becklin, E E; Salim, S; Kremenek, T; Thompson, D; Soifer, B T; Neugebauer, G; McLean, I

    2003-01-01

    We have obtained the first detection of spectral absorption lines in one of the high-velocity stars in the vicinity of the Galaxy's central supermassive black hole. Both Brgamma (2.1661 micron) and He I (2.1126 micron) are seen in absorption in S0-2 with equivalent widths (2.8+-0.3 Ang & 1.7+-0.4 Ang) and an inferred stellar rotational velocity (220+-40 km/s) that are consistent with that of an O8-B0 dwarf, which suggests that it is a massive (~15 Msun), young (<10 Myr) main sequence star. This presents a major challenge to star formation theories, given the strong tidal forces that prevail over all distances reached by S0-2 in its current orbit (130 - 1900 AU) and the difficulty in migrating this star inward during its lifetime from further out where tidal forces should no longer preclude star formation. The radial velocity measurements (-510+-40 km/s) and our reported proper motions for S0-2 strongly constrain its orbit, providing a direct measure of the black hole mass of 4.1(+-0.6)x10^6(Ro/8kpc)^3 ...

  5. Types of Paradox in Physics

    E-Print Network [OSTI]

    Dragoljub A. Cucic

    2009-12-09

    Paradoxes are a relatively frequent occurrence in physics. The nature of their genesis is diverse and they are found in all branches of physics. There are a number of general and special classifications of paradoxes, but there are no classifications of paradoxes in physics. Nowadays, physics is a fundamental and rather formalized science, the paradoxes of which imply falsity and imprecision. One of the basic methods of addressing a problem is to present classifications that facilitate its formulation and study. This work groups together the paradoxes in physics according to certain common characteristics, which should assist in explaining the causes for paradox formation.

  6. ECO-WARRIORS IN THE SUPERMARKET?: EVALUATING THE UK SUSTAINABLE CONSUMPTION

    E-Print Network [OSTI]

    Bateman, Ian J.

    consumption and production; ecological citizenship; government policy; environmental decisionECO-WARRIORS IN THE SUPERMARKET?: EVALUATING THE UK SUSTAINABLE CONSUMPTION STRATEGY AS A TOOL?: EVALUATING THE UK SUSTAINABLE CONSUMPTION STRATEGY AS A TOOL FOR ECOLOGICAL CITIZENSHIP by Gill Seyfang

  7. Cultivating Sustainable Coffee: Persistent Paradoxes

    E-Print Network [OSTI]

    Bacon, Christopher M.; Mendez, Ernesto; Fox, Jonathan A

    2008-01-01

    Paradoxes Christopher M . Bacon, V. Ernesto Méndez, andfood: Good food? December 9. Bacon, C. M . 2006. Estudio deProductores de Comercio Justo. Bacon, C. M . forthcoming. A

  8. Col. Shauna Snyder aims for Gold during World Games By Annette Coward, Army Warrior Transition Command

    E-Print Network [OSTI]

    US Army Corps of Engineers

    du Sport Militaire (CISM) World Games being held in Mungyeong, South Korea, October 2-11 2015. She Warriors competing in para- track and field and para-archery. Founded in 1948, CISM is the second largest of its kind in the world. The United States joined CISM in 1951 and remains one of the most active

  9. CyberCIEGE vs CyberOps NetWarrior September 2009

    E-Print Network [OSTI]

    that fails to give the player a sense of what the countermeasure actually does. In CyberCIEGE, VPN gateways to the same workstation that has a VPN tunnel into the corporate network. In NetWarrior, a VPN is simply

  10. Representing the Daoist God Zhenwu, the Perfected Warrior, in Late Imperial China

    E-Print Network [OSTI]

    Giuffrida, Noelle

    2008-02-29

    Zhenwu, the Perfected Warrior, emerged as an anthropomorphic deity in the early Northern Song (960-1126) and reached the peak of his popularity in the Ming (1368-1644). Prior to this time he was known as Xuanwu, the Dark ...

  11. Love, Sacrifice, and Honor: Warrior Virtues and the American Soldiers’ Experience of World War II 

    E-Print Network [OSTI]

    Williamson, Benjamin K.

    2010-07-14

    ....................................................... 40 Elliot Johnson................................................................................ 42 VI AWARDING VIRTUE: MEDALS OF HONOR AND THE AMERICAN SYSTEM OF MILITARY COMMENDATION................ 45 History of the American system... of morality and virtue. Furthermore, I will investigate the way in which ?warrior virtues? operated?or failed to operate?in the experiences of soldiers in World War II. As stated by James Turner Johnson in his book Morality and Contemporary Warfare, ?The...

  12. Some remarks on black hole thermodynamics

    E-Print Network [OSTI]

    R. Y. Chiao

    2011-02-04

    Two thermodynamic "paradoxes" of black hole physics are re-examined. The first is that there is a thermal instability involving two coupled blackbody cavities containing two black holes, and second is that a classical black hole can swallow up entropy in the form of ambient blackbody photons without increasing its mass. The resolution of the second paradox by Bekenstein and by Hawking is re-visited. The link between Hawking radiation and Wigner's superluminal tunneling time is discussed using two equivalent Feynman diagrams, and Feynman's re-interpretation principle.

  13. Secondary oil recovery from selected Carter sandstone oilfields--Black Warrior Basin, Alabama. Final report

    SciTech Connect (OSTI)

    Anderson, J.C.

    1995-02-01

    Producibility problems, such as low reservoir pressure and reservoir heterogeneity, have severely limited oil production from the Central Bluff and North Fairview fields. Specific objectives for this project were: To successfully apply detailed geologic and engineering studies with conventional waterflood technologies to these fields in an effort to increase the ultimate economic recovery of oil from Carter sandstone fields; To extensively model, test and evaluate these technologies; thereby, developing a sound methodology for their use and optimization; and To team with Advanced Resources International and the US DOE to assimilate and transfer the information and results gathered from this study to other oil companies to encourage the widespread use of these technologies. At Central Bluff, water injection facilities were constructed and water injection into one well began in January 1993. Oil response from the waterflood has been observed at both producing wells. One of the producing wells has experienced early water breakthrough and a concomitant drop in secondary oil rate. A reservoir modeling study was initiated to help develop an appropriate operating strategy for Central Bluff. For the North Fairview unit waterflood, a previously abandoned well was converted for water injection which began in late June 1993. The reservoir is being re-pressurized, and unit water production has remained nil since flood start indicating the possible formation of an oil bank. A reservoir simulation to characterize the Carter sand at North Fairview was undertaken and the modeling results were used to forecast field performance. The project was terminated due to unfavorable economics. The factors contributing to this decision were premature water breakthrough at Central Bluff, delayed flood response at North Fairview and stalled negotiations at the South Bluff site.

  14. Black Warrior: Sub-soil gas and fluid inclusion exploration and slim well drilling

    Broader source: Energy.gov [DOE]

    DOE Geothermal Peer Review 2010 - Presentation. Project Objectives: Discover a blind, low-moderate temperature resource: Apply a combination of detailed sub-soil gas, hydrocarbon, and isotope data to define possible upflow areas; Calibrate the sub-soil chemistry with down-hole fluid inclusion stratigraphy and fluid analyses to define a follow-up exploration drilling target; Create short term jobs and long term employment through resource exploration, development and power plant operation; Extend and adapt the DOE sub-soil 2 meter probe technology to gas sampling.

  15. Black Warrior: Sub-soil Gas and Fluid Inclusion Exploration and...

    Open Energy Info (EERE)

    prospect. - Calibrate the sub-soil chemistry with down hole fluid inclusion stratigraphy analyses to define a follow-up exploration drilling target. - Successful...

  16. File:Black.Warrior.Basin usgs.map.pdf | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QAsource History View New Pages Recent Changes AllApschem.pdf Jump to: navigation,

  17. Flow Test At Black Warrior Area (DOE GTP) | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QAsource History View New PagesSustainable Urban Transport Jump to:Flanders,Information 5thsource

  18. 2-M Probe At Black Warrior Area (DOE GTP) | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmental Jump to:EAand Dalton Jump to:Wylie, Texas:V.S.A.Energy

  19. Black Warrior: Sub-soil Gas and Fluid Inclusion Exploration and Slim Well

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmental JumpInformationBio-Gas Technologies, LLCMichigan:Earth,Drilling Geothermal

  20. Compound and Elemental Analysis At Black Warrior Area (DOE GTP) | Open

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX ECoopButtePower Ventures JumpCommercial Jump to:Technology Corporation

  1. Core Analysis At Black Warrior Area (DOE GTP) | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX ECoopButtePower Ventures JumpCommercialRenewableGlobal L P JumpFarmCopisaCoram

  2. Cold warriors target arms control (Journal Article) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfate Reducing Bacteria (TechnicalTransmission,TextitSciTechinRequirementsorModelingandCold warriors

  3. Compliance Monitoring of Underwater Blasting for Rock Removal at Warrior Point, Columbia River Channel Improvement Project, 2009/2010

    SciTech Connect (OSTI)

    Carlson, Thomas J.; Johnson, Gary E.; Woodley, Christa M.; Skalski, J. R.; Seaburg, Adam

    2011-05-10

    The U.S. Army Corps of Engineers, Portland District (USACE) conducted the 20-year Columbia River Channel Improvement Project (CRCIP) to deepen the navigation channel between Portland, Oregon, and the Pacific Ocean to allow transit of fully loaded Panamax ships (100 ft wide, 600 to 700 ft long, and draft 45 to 50 ft). In the vicinity of Warrior Point, between river miles (RM) 87 and 88 near St. Helens, Oregon, the USACE conducted underwater blasting and dredging to remove 300,000 yd3 of a basalt rock formation to reach a depth of 44 ft in the Columbia River navigation channel. The purpose of this report is to document methods and results of the compliance monitoring study for the blasting project at Warrior Point in the Columbia River.

  4. Errors and paradoxes in quantum mechanics

    E-Print Network [OSTI]

    D. Rohrlich

    2007-08-28

    Errors and paradoxes in quantum mechanics, entry in the Compendium of Quantum Physics: Concepts, Experiments, History and Philosophy, ed. F. Weinert, K. Hentschel, D. Greenberger and B. Falkenburg (Springer), to appear

  5. Quantum chaos inside Black Holes

    E-Print Network [OSTI]

    Addazi, Andrea

    2015-01-01

    We show how semiclassical black holes can be reinterpreted as an effective geometry, composed of a large ensamble of horizonless naked singularities (eventually smoothed at the Planck scale). We call this new items {\\it frizzyballs}, which can be rigorously defined by euclidean path integral approach. This has interesting implications regarding information paradoxes. We demonstrate that infalling information will chaotically propagate inside this system before going to the full quantum gravity regime (Planck scale).

  6. Quantum chaos inside Black Holes

    E-Print Network [OSTI]

    Andrea Addazi

    2015-08-30

    We show how semiclassical black holes can be reinterpreted as an effective geometry, composed of a large ensamble of horizonless naked singularities (eventually smoothed at the Planck scale). We call this new items {\\it frizzyballs}, which can be rigorously defined by euclidean path integral approach. This has interesting implications regarding information paradoxes. We demonstrate that infalling information will chaotically propagate inside this system before going to the full quantum gravity regime (Planck scale).

  7. Introduction to Black Hole Evaporation

    E-Print Network [OSTI]

    Pierre-Henry Lambert

    2014-01-16

    These lecture notes are an elementary and pedagogical introduction to the black hole evaporation, based on a lecture given by the author at the Ninth Modave Summer School in Mathematical Physics and are intended for PhD students. First, quantum field theory in curved spacetime is studied and tools needed for the remaining of the course are introduced. Then, quantum field theory in Rindler spacetime in 1+1 dimensions and in the spacetime of a spherically collapsing star are considered, leading to Unruh and Hawking effects, respectively. Finally, some consequences such as thermodynamics of black holes and information loss paradox are discussed.

  8. Managing the Paradoxes of Perfection in Women's Daily Lives 

    E-Print Network [OSTI]

    Hampsten, Katherine

    2012-10-19

    This study explores the paradoxical nature of cultural norms of feminine perfection and the strategies women employ to manage those paradoxes. Following an analysis of the cultural discourses surrounding women and perfection, ...

  9. Bueno and Colyvan on Yablo’s Paradox 

    E-Print Network [OSTI]

    Ketland, Jeffrey

    2004-01-01

    This is a response to a paper “Paradox without satisfaction”, Analysis 63, 152-6 (2003) by Otavio Bueno and Mark Colyvan on Yablo’s paradox. I argue that this paper makes several substantial mathematical errors which vitiate ...

  10. Evidence Against Klein Paradox in Graphene

    E-Print Network [OSTI]

    Daniela Dragoman

    2008-02-23

    It is demonstrated that both transmission and reflection coefficients associated to the Klein paradox at a step barrier are positive and less than unity, so that the particle-antiparticle pair creation mechanism commonly linked to this phenomenon is not necessary. Because graphene is a solid-state testing ground for quantum electrodynamics phenomena involving massless Dirac fermions we suggest that the transport characteristic through a p-n graphene junction can decide between the results obtained in this paper and the common Klein paradox theory, which imply negative transmission and higher-than-unity reflection coefficients. Recent experimental evidence supports our findings.

  11. Quantum, Photo-Electric Single Capacitor Paradox

    E-Print Network [OSTI]

    Darko Kapor; Vladan Pankovic

    2009-12-10

    In this work single capacitor paradox (a variation of the remarkable two capacitor paradox) is considered in a new, quantum discrete form. Simply speaking we consider well-known usual, photoelectric effect experimental device, i.e. photo electric cell, where cathode and anode are equivalently charged but non-connected. It, obviously, represents a capacitor that initially, i.e. before action of the photons with individual energy equivalent to work function, holds corresponding energy of the electrical fields between cathode and anode. Further, we direct quantum discretely photons, one by one, toward cathode where according to photo-electrical effect electrons discretely, one by one, will be emitted and directed toward anode. It causes discrete discharge of the cell, i.e. capacitor and discrete decrease of the electrical field. Finally, total discharge of the cell, i.e. capacitor, and total disappearance of the electrical field and its energy will occur. Given, seemingly paradoxical, capacitor total energy loss can be simply explained without any dissipative effects (Joule heating or electromagnetic waves emission can be neglected as high order small corrections) by work done by the electrical field by movement of the electrons from cathode to anode. (Remarkable two capacitors paradox can be, obviously, formulated and explained in the completely analogous way.)

  12. Quantum Mechanics: Structures, Axioms and Paradoxes

    E-Print Network [OSTI]

    Aerts, Diederik

    Quantum Mechanics: Structures, Axioms and Paradoxes Diederik Aerts Center Leo Apostel, Brussels present an analysis of quantum mechanics and its problems and para- doxes taking into account the results a genuine incomplete- ness of standard quantum mechanics, however not an incompleteness that means

  13. Quantum simulation of the Klein paradox

    E-Print Network [OSTI]

    Gerritsma, R; Kirchmair, G; Zähringer, F; Hempel, C; Casanova, J; García-Ripoll, J J; Solano, E; Blatt, R; Roos, C F

    2010-01-01

    In 1929 Oskar Klein obtained a surprising result when investigating the scattering of a relativistic electron from an electrostatic potential step using the Dirac equation. Klein found that the electron can propagate through the step, without damping, and that the probability for this happening increases with the step height---a result commonly known as the Klein paradox. Since direct experimental investigations are lacking, and would be very challenging, the Klein paradox remains a much debated and investigated topic in relativistic quantum mechanics. Driven by the experimental inaccessibility of relativistic quantum systems there has been recent interest in performing quantum simulations. In this paper we report on the quantum simulation of relativistic scattering dynamics and the observation of Klein tunneling, using trapped ions. The combination of precise engineering of all terms in the simulated Hamiltonian and the ability to prepare arbitrary initial states enables the investigation of a wide range of ...

  14. Information Preservation and Weather Forecasting for Black Holes

    E-Print Network [OSTI]

    S. W. Hawking

    2014-01-22

    It has been suggested [1] that the resolution of the information paradox for evaporating black holes is that the holes are surrounded by firewalls, bolts of outgoing radiation that would destroy any infalling observer. Such firewalls would break the CPT invariance of quantum gravity and seem to be ruled out on other grounds. A different resolution of the paradox is proposed, namely that gravitational collapse produces apparent horizons but no event horizons behind which information is lost. This proposal is supported by ADS-CFT and is the only resolution of the paradox compatible with CPT. The collapse to form a black hole will in general be chaotic and the dual CFT on the boundary of ADS will be turbulent. Thus, like weather forecasting on Earth, information will effectively be lost, although there would be no loss of unitarity.

  15. An intuitive approach to inertial forces and the centrifugal force paradox in general relativity

    E-Print Network [OSTI]

    Rickard Jonsson

    2007-08-18

    As the velocity of a rocket in a circular orbit near a black hole increases, the outwardly directed rocket thrust must increase to keep the rocket in its orbit. This feature might appear paradoxical from a Newtonian viewpoint, but we show that it follows naturally from the equivalence principle together with special relativity and a few general features of black holes. We also derive a general relativistic formalism of inertial forces for reference frames with acceleration and rotation. The resulting equation relates the real experienced forces to the time derivative of the speed and the spatial curvature of the particle trajectory relative to the reference frame. We show that an observer who follows the path taken by a free (geodesic) photon will experience a force perpendicular to the direction of motion that is independent of the observers velocity. We apply our approach to resolve the submarine paradox, which regards whether a submerged submarine in a balanced state of rest will sink or float when given a horizontal velocity if we take relativistic effects into account. We extend earlier treatments of this topic to include spherical oceans and show that for the case of the Earth the submarine floats upward if we take the curvature of the ocean into account.

  16. The paradox of strategic environmental assessment

    SciTech Connect (OSTI)

    Bidstrup, Morten Hansen, Anne Merrild

    2014-07-01

    Strategic Environmental Assessment (SEA) is a tool that can facilitate sustainable development and improve decision-making by introducing environmental concern early in planning processes. However, various international studies conclude that current planning practice is not taking full advantage of the tool, and we therefore define the paradox of SEA as the methodological ambiguity of non-strategic SEA. This article explores causality through at three-step case study on aggregates extraction planning in Denmark, which consists of a document analysis; a questionnaire survey and follow-up communication with key planners. Though the environmental reports on one hand largely lack strategic considerations, practitioners express an inherent will for strategy and reveal that their SEAs in fact have been an integrated part of the planning process. Institutional context is found to be the most significant barrier for a strategy and this suggests that non-strategic planning setups can prove more important than non-strategic planning in SEA practice. Planners may try to execute strategy within the confinements of SEA-restricted planning contexts; however, such efforts can be overlooked if evaluated by a narrow criterion for strategy formation. Consequently, the paradox may also spark from challenged documentation. These findings contribute to the common understanding of SEA quality; however, further research is needed on how to communicate and influence the strategic options which arguably remain inside non-strategic planning realities. - Highlights: • International studies conclude that SEAs are not strategic. = The paradox of SEA. • Even on the highest managerial level, some contexts do not leave room for strategy. • Non-strategic SEA can derive from challenged documentation. • Descriptive and emergent strategy formation can, in practice, be deemed non-strategic.

  17. Zeno's First Paradox of Motion: A Cartesian Perspective

    E-Print Network [OSTI]

    Balster, Lori

    Zeno's First Paradox of Motion: A Cartesian Perspective Lori Bolster University of Dayton Before I introduce some of Descartes' perspective into a discussion of Zeno's First Paradox of Motion, I would first like to restate in general what Zeno...'s First Paradox of Motion is. Essentially, Zeno says that, in order for motion from point A to point B to occur, one half of that distance must first be traveled. In order for one half of that distance to be traveled, one fourth of that distance must...

  18. The shadow interpretation versus quantum paradoxes

    E-Print Network [OSTI]

    Leffler, Warren

    2009-01-01

    This paper explores the consequences of denying the "emptiness of paths not taken," EPNT, premise of Bernstein, Greenberger, Horne, and Zeilinger (BGHZ) in their paper titled, Bell theorem without inequalities.[ ] Carrying out the negation of EPNT leads to the concept of a "shadow stream." Streams are essentially particle implementations of the paths in Feynman path-integrals, resulting in a simple and consistent extension of the standard axioms for quantum mechanics. The construct provides elegant resolutions of single- and multi-particle interference paradoxes. Moreover, combining the argument of this paper with that of BGHZ shows that there are just two choices for quantum foundations: interpretations closely similar to the present one or those that harbor instantaneous action at a distance.

  19. EPR, Bell, Schrodinger's cat, and the Monty Hall Paradox

    E-Print Network [OSTI]

    Doron Cohen

    2007-04-09

    The purpose of this manuscript is to provide a short pedagogical explanation why "quantum collapse" is not a metaphysical event, by pointing out the analogy with a "classical collapse" which is associated with the Monty Hall Paradox.

  20. Mpemba paradox: Hydrogen bond memory and water-skin supersolidity

    E-Print Network [OSTI]

    Chang Q Sun

    2015-01-05

    Numerical reproduction of measurements, experimental evidence for skin super-solidity and hydrogen-bond memory clarified that Mpemba paradox integrates the heat emission-conduction-dissipation dynamics in the source-path-drain cycle system.

  1. LE PARADOXE DE L'AXE APPRENTISSAGE ORGANISATIONNEL ET

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    'exemple de BSC développés dans deux établissements hospitaliers. Au préalable une revue de la littérature for this management tool. Nevertheless, a detailed analysis of various papers shows a certain paradox between

  2. Effect of Substrate Roughness on D Spacing Supports Theoretical Resolution of Vapor Pressure Paradox

    E-Print Network [OSTI]

    Nagle, John F.

    Effect of Substrate Roughness on D Spacing Supports Theoretical Resolution of Vapor Pressure with and provides experimental support for a recently proposed theoretical resolution of the vapor pressure paradox has been called the vapor pressure paradox (Rand and Parsegian, 1989). Resolving this paradox

  3. "Audacity or Precision": The Paradoxes of Henri Villat's Fluid Mechanics

    E-Print Network [OSTI]

    Aubin, David

    1 "Audacity or Precision": The Paradoxes of Henri Villat's Fluid Mechanics in Interwar France David researches on fluid mechanics. Most of his original work was done before the First Word War; it was highly on, he held the fluid mechanics chair established by the Air Ministry at the Sorbonne in Paris

  4. Dispatch R637 Photosynthesis: The paradox of carbon dioxide efflux

    E-Print Network [OSTI]

    Falkowski, Paul G.

    Dispatch R637 Photosynthesis: The paradox of carbon dioxide efflux Paul G. Falkowski The discovery 0960-9822 Photosynthesis in the world oceans accounts for approximately 40% of the global carbon fixed each year on Earth [1]. The vast majority of photosynthetic carbon fixation, by far, is carried out

  5. Black Holes in the Cosmos, the Lab, and in Fundamental Physics (1/3)

    ScienceCinema (OSTI)

    None

    2011-10-06

    Black holes present the extreme limits of physics. They are ubiquitous in the cosmos, and in some extra-dimensional scenarios they could be produced at colliders. They have also yielded a puzzle that challenges the foundations of physics. These talks will begin with an overview of the basics of black hole physics, and then briefly summarize some of the exciting developments with cosmic black holes. They will then turn to properties of quantum black holes, and the question of black hole production in high energy collisions, perhaps beginning with the LHC. I will then overview the apparent paradox emerging from Hawking's discovery of black hole evaporation, and what it could be teaching us about the foundations of quantum mechanics and gravity.

  6. Black Holes in the Cosmos, the Lab, and in Fundamental Physics (3/3)

    ScienceCinema (OSTI)

    None

    2011-10-06

    Black holes present the extreme limits of physics. They are ubiquitous in the cosmos, and in some extra-dimensional scenarios they could be produced at colliders. They have also yielded a puzzle that challenges the foundations of physics. These talks will begin with an overview of the basics of black hole physics, and then briefly summarize some of the exciting developments with cosmic black holes. They will then turn to properties of quantum black holes, and the question of black hole production in high energy collisions, perhaps beginning with the LHC. I will then overview the apparent paradox emerging from Hawking's discovery of black hole evaporation, and what it could be teaching us about the foundations of quantum mechanics and gravity.

  7. Black Holes in the Cosmos, the Lab, and in Fundamental Physics (2/3)

    ScienceCinema (OSTI)

    None

    2011-10-06

    Black holes present the extreme limits of physics. They are ubiquitous in the cosmos, and in some extra-dimensional scenarios they could be produced at colliders. They have also yielded a puzzle that challenges the foundations of physics. These talks will begin with an overview of the basics of black hole physics, and then briefly summarize some of the exciting developments with cosmic black holes. They will then turn to properties of quantum black holes, and the question of black hole production in high energy collisions, perhaps beginning with the LHC. I will then overview the apparent paradox emerging from Hawking's discovery of black hole evaporation, and what it could be teaching us about the foundations of quantum mechanics and gravity.

  8. Quantum Jump from Singularity to Outside of Black Hole

    E-Print Network [OSTI]

    Dündar, Furkan Semih

    2015-01-01

    Considering the role of black hole singularity in quantum evolution, a resolution to the firewall paradox is presented. It is emphasized that if an observer has the singularity as a part of his spacetime, then the semi-classical evolution would be non-unitary as viewed by him. Specifically, a free-falling observer inside the black hole would have a Hilbert space with non-unitary evolution; a quantum jump for particles encountering the singularity to outside of the horizon as part of late radiations in black hole evaporation. Accordingly, we elaborate the first postulate of black hole complementarity: freely falling observers who pass through the event horizon would have non-unitarity evolutions. The non-unitary evolution is such that it does not have physically measurable effects for them. Besides, no information would be lost in singularity. Taking the modified picture into account, the firewall paradox {can be} resolved, respecting No Drama. A by-product of our modification is that roughly half of the mass ...

  9. 1-D Dirac Equation, Klein Paradox and Graphene

    E-Print Network [OSTI]

    S. P. Bowen

    2008-07-23

    Solutions of the one dimensional Dirac equation with piece-wise constant potentials are presented using standard methods. These solutions show that the Klein Paradox is non-existent and represents a failure to correctly match solutions across a step potential. Consequences of this exact solution are studied for the step potential and a square barrier. Characteristics of massless Dirac states and the momentum linear band energies for Graphene are shown to have quite different current and momentum properties.

  10. Intracellular L-arginine concentration does not determine NO production in endothelial cells: Implications on the 'L-arginine paradox'

    SciTech Connect (OSTI)

    Shin, Soyoung; Mohan, Srinidi; Fung, Ho-Leung

    2011-11-04

    Highlights: Black-Right-Pointing-Pointer Our findings provide a possible solution to the 'L-arginine paradox'. Black-Right-Pointing-Pointer Extracellular L-arginine concentration is the major determinant of NO production. Black-Right-Pointing-Pointer Cellular L-arginine action is limited by cellular ARG transport, not the K{sub m} of NOS. Black-Right-Pointing-Pointer We explain how L-arginine supplementation can work to increase endothelial function. -- Abstract: We examined the relative contributory roles of extracellular vs. intracellular L-arginine (ARG) toward cellular activation of endothelial nitric oxide synthase (eNOS) in human endothelial cells. EA.hy926 human endothelial cells were incubated with different concentrations of {sup 15}N{sub 4}-ARG, ARG, or L-arginine ethyl ester (ARG-EE) for 2 h. To modulate ARG transport, siRNA for ARG transporter (CAT-1) vs. sham siRNA were transfected into cells. ARG transport activity was assessed by cellular fluxes of ARG, {sup 15}N{sub 4}-ARG, dimethylarginines, and L-citrulline by an LC-MS/MS assay. eNOS activity was determined by nitrite/nitrate accumulation, either via a fluorometric assay or by{sup 15}N-nitrite or estimated {sup 15}N{sub 3}-citrulline concentrations when {sup 15}N{sub 4}-ARG was used to challenge the cells. We found that ARG-EE incubation increased cellular ARG concentration but no increase in nitrite/nitrate was observed, while ARG incubation increased both cellular ARG concentration and nitrite accumulation. Cellular nitrite/nitrate production did not correlate with cellular total ARG concentration. Reduced {sup 15}N{sub 4}-ARG cellular uptake in CAT-1 siRNA transfected cells vs. control was accompanied by reduced eNOS activity, as determined by {sup 15}N-nitrite, total nitrite and {sup 15}N{sub 3}-citrulline formation. Our data suggest that extracellular ARG, not intracellular ARG, is the major determinant of NO production in endothelial cells. It is likely that once transported inside the cell, ARG can no longer gain access to the membrane-bound eNOS. These observations indicate that the 'L-arginine paradox' should not consider intracellular ARG concentration as a reference point.

  11. Our Indian Warriors 

    E-Print Network [OSTI]

    2012-03-05

    TRANSCRIPTION; MESSAGE: Thank you so much for your L. L. dearest I came Home this morning Sunday I expect your P C will arrive in the morning I will do whatever is arrange Love [illegible]; SENT TO: Miss L. Richards; Coopersale Hall; Epping; Essex...

  12. Carbon smackdown: wind warriors

    ScienceCinema (OSTI)

    Glen Dahlbacka of the Accelerator & Fusion Research Division and Ryan Wiser of the Environmental Energy Technologies Division are the speakers.

    2010-09-01

    July 16. 2010 carbon smackdown summer lecture: learn how Berkeley Lab scientists are developing wind turbines to be used in an urban setting, as well as analyzing what it will take to increase the adoption of wind energy in the U.S.

  13. Globalization and Religion in Historical Perspective: A Paradoxical Relationship

    E-Print Network [OSTI]

    Herrington, Luke M.

    might characterize this as a kind of negative feedback loop, but the truth is that religion-globalization relationships are not couched exclusively in conflict. For this reason, the agent-opponent paradox is the subject of this article. Religions 2013... stream_size 79476 stream_content_type text/plain stream_name Herrington_globalization and religion.pdf.txt stream_source_info Herrington_globalization and religion.pdf.txt Content-Encoding UTF-8 Content-Type text/plain; charset...

  14. WORKING PAPER N 2011 30 Measuring Poverty Without The Mortality Paradox

    E-Print Network [OSTI]

    Boyer, Edmond

    WORKING PAPER N° 2011 ­ 30 Measuring Poverty Without The Mortality Paradox Mathieu Lefebvre Pierre, poverty measurement, censored income profile PARIS-JOURDAN SCIENCES ECONOMIQUES 48, BD JOURDAN ­ E;Measuring Poverty Without The Mortality Paradox Mathieu Lefebvre, Pierre Pestieauy and Gregory Ponthierez

  15. In Dale Jacquette (ed), Philosophy of Logic: 485518 The Mathematics of Skolem's Paradox

    E-Print Network [OSTI]

    Bays, Timothy

    --and quite a bit more interesting--than it's usually taken to be. Further, because philosophical discussions side of Skolem's Paradox. In particular, I don't attempt to survey all the things philosophers have simplest form, Skolem's Paradox involves a (seeming) conflict between two theorems of modern logic: Cantor

  16. A Case where a Paradox Like Braess's Occurs in the Nash Equilibrium but Does Not Occur in the Wardrop Equilibrium

    E-Print Network [OSTI]

    A Case where a Paradox Like Braess's Occurs in the Nash Equilibrium but Does Not Occur of the other individuals. Another framework in which such a paradox may occur is that of the Nash equilibrium­ negligible eoeect on the other players. It is natural to expect the same type of paradox in the Nash equilib

  17. Del Black

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HAB Packet HanfordDOEDanielDe novo Design ofDefects LeadDel Black Del

  18. Working Paper --Department of Operations and Information Management, The Wharton School THE ENVIRONMENTAL PARADOX OF BICYCLING

    E-Print Network [OSTI]

    Handy, Susan L.

    requirements of transportation by bicycle relative to automobiles. The environmental benefits of human power longevity of those who engage in physical activity. Paradoxically, increased use of human power Meyer Keywords: environment, energy, bicycle, bicycling, human power, transportation, longevity, human

  19. Time operator for the quantum harmonic oscillator: resolution of an apparent paradox

    E-Print Network [OSTI]

    Alex Granik; H. Ralph Lewis

    2000-06-14

    An apparent paradox is resolved that concerns the existence of time operators which have been derived for the quantum harmonic oscillator. There is an apparent paradox because, although a time operator is canonically conjugate to the Hamiltonian, it has been asserted that no operator exists that is canonically conjugate to the Hamiltonian. In order to resolve the apparent paradox, we work in a representation where the phase operator is diagonal. The boundary condition on wave functions is such that they be periodic in the phase variable, which is related to the (continuous) eigenvalue of the time operator. Matrix elements of the commutator of the time operator with the Hamiltonian involve the phase variable itself in addition to periodic functions of the phase variable. The Hamiltonian is not hermitian when operating in space that includes the phase variable itself. The apparent paradox is resolved when this non-hermeticity is taken into account correctly in the evaluation of matrix elements of the commutation relation.

  20. A Unitary Model of The Black Hole Evaporation

    E-Print Network [OSTI]

    Yu-Lei Feng; Yi-Xin Chen

    2014-12-16

    A unitary effective field model of the black hole evaporation is proposed to satisfy almost the four postulates of the black hole complementarity (BHC). In this model, we enlarge a black hole-scalar field system by adding an extra radiation detector that couples with the scalar field. After performing a partial trace over the scalar field space, we obtain an effective entanglement between the black hole and the detector (or radiation in it). As the whole system evolves, the S-matrix formula can be constructed formally step by step. Without local quantum measurements, the paradoxes of the information loss and AMPS's firewall can be resolved. However, the information can be lost due to quantum decoherence, as long as some local measurement has been performed on the detector to acquire the information of the radiation in it. But unlike Hawking's completely thermal spectrum, some residual correlations can be found in the radiations. All these considerations can be simplified in a qubit model that provides a \\emph{modified quantum teleportation} to transfer the information via an EPR pairs.

  1. Supermassive Black Holes

    E-Print Network [OSTI]

    Laura Ferrarese; David Merritt

    2002-06-13

    After a brief historical introduction, we summarize current efforts and accomplishments in the study of supermassive black holes.

  2. Black Pine Engineering

    Office of Energy Efficiency and Renewable Energy (EERE)

    Black Pine Engineering is commercializing a disruptive technology in the turbomachinery industry. Using a patented woven composite construction, Black Pine Engineering can make turbomachines (turbines, compressors) that are cheaper and lighter than competing technologies. Using this technology, Black Pine Engineering will sell turbo-compressors which solve the problem of wasted steam in geothermal power plants.

  3. Magnetized static black Saturn

    E-Print Network [OSTI]

    Stoytcho S. Yazadjiev

    2008-02-06

    We construct a new static solution to the 5D Einstein-Maxwell equations describing a static black hole surrounded by a non-rotating dipole black ring. The configuration is kept in equilibrium by an external magnetic field interacting with the dipole charge of the black ring. The properties of the black Saturn-like configuration are studied and the basic physical quantities are calculated. The solution demonstrates 2-fold continuous non-uniqueness of the 5D magnetized static neutral black objects for fixed total mass and Melvin background.

  4. Paradoxes of cosmological physics in the beginning of the 21-st century

    E-Print Network [OSTI]

    Yurij Baryshev

    2015-01-04

    In the history of cosmology physical paradoxes played important role for development of contemporary world models. Within the modern standard cosmological model there are both observational and conceptual cosmological paradoxes which stimulate to search their solution. Confrontation of theoretical predictions of the standard cosmological model with the latest astrophysical observational data is considered. A review of conceptual problems of the Friedmann space expending models, which are in the bases of modern cosmological model, is discussed. The main paradoxes, which are discussed in modern literature, are the Newtonian character of the exact Friedmann equation, the violation of the energy conservation within any comoving local volume, violation of the limiting recession velocity of galaxies for the observed high redshift objects. Possible observational tests of the nature of the cosmological redshift are discussed

  5. Paradoxes of cosmological physics in the beginning of the 21-st century

    E-Print Network [OSTI]

    Baryshev, Yurij

    2015-01-01

    In the history of cosmology physical paradoxes played important role for development of contemporary world models. Within the modern standard cosmological model there are both observational and conceptual cosmological paradoxes which stimulate to search their solution. Confrontation of theoretical predictions of the standard cosmological model with the latest astrophysical observational data is considered. A review of conceptual problems of the Friedmann space expending models, which are in the bases of modern cosmological model, is discussed. The main paradoxes, which are discussed in modern literature, are the Newtonian character of the exact Friedmann equation, the violation of the energy conservation within any comoving local volume, violation of the limiting recession velocity of galaxies for the observed high redshift objects. Possible observational tests of the nature of the cosmological redshift are discussed

  6. Exploring the isopycnal mixing and helium-heat paradoxes in a suite of Earth System Models

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Gnanadesikan, A.; Abernathey, R.; Pradal, M.-A.

    2014-11-20

    This paper uses a suite of Earth System models which simulate the distribution of He isotopes and radiocarbon to examine two paradoxes in Earth science. The helium-heat paradox refers to the fact that helium emissions to the deep ocean are far lower than would be expected given the rate of geothermal heating, since both are thought to be the result of radioactive decay in the earth's interior. The isopycnal mixing paradox comes from the fact that many theoretical parameterizations of the isopycnal mixing coefficient ARedi that link it to baroclinic instability project it to be small (of order a fewmore »hundred m2 s?1) in the ocean interior away from boundary currents. However, direct observations using tracers and floats (largely in the upper ocean) suggest that values of this coefficient are an order of magnitude higher. Because helium isotopes equilibrate rapidly with the atmosphere, but radiocarbon equilibrates slowly, it might be thought that resolving the isopycnal mixing paradox in favor of the higher observational estimates of ARedi might also solve the helium paradox. In this paper we show that this is not the case. In a suite of models with different spatially constant and spatially varying values of ARedi the distribution of radiocarbon and helium isotopes is sensitive to the value of ARedi. However, away from strong helium sources in the Southeast Pacific, the relationship between the two is not sensitive, indicating that large-scale advection is the limiting process for removing helium and radiocarbon from the deep ocean. The helium isotopes, in turn, suggest a higher value of ARedi in the deep ocean than is seen in theoretical parameterizations based on baroclinic growth rates. We argue that a key part of resolving the isopycnal mixing paradox is to abandon the idea that ARedi has a direct relationship to local baroclinic instability and to the so called "thickness" mixing coefficient AGM.« less

  7. The paradoxical Peking opera : performing tradition, history, and politics in 1949-1967 China

    E-Print Network [OSTI]

    Liao, Fan

    2012-01-01

    integrity were normally given a color black. “Characters represent certain standardized and clearly gendered personalities

  8. Bicycling Black Rings

    E-Print Network [OSTI]

    Henriette Elvang; Maria J. Rodriguez

    2008-01-25

    We present detailed physics analyses of two different 4+1-dimensional asymptotically flat vacuum black hole solutions with spin in two independent planes: the doubly spinning black ring and the bicycling black ring system ("bi-rings"). The latter is a new solution describing two concentric orthogonal rotating black rings which we construct using the inverse scattering technique. We focus particularly on extremal zero-temperature limits of the solutions. We construct the phase diagram of currently known zero-temperature vacuum black hole solutions with a single event horizon, and discuss the non-uniqueness introduced by more exotic black hole configurations such as bi-rings and multi-ring saturns.

  9. Bicycling Black Rings

    E-Print Network [OSTI]

    Elvang, Henriette

    2008-01-01

    We present detailed physics analyses of two different 4+1-dimensional asymptotically flat vacuum black hole solutions with spin in two independent planes: the doubly spinning black ring and the bicycling black ring system ("bi-rings"). The latter is a new solution describing two concentric orthogonal rotating black rings which we construct using the inverse scattering technique. We focus particularly on extremal zero-temperature limits of the solutions. Such limits exist for both types of solutions; for the bi-rings it is obtained when the two rings drag each other to extremality through the effect of gravitational frame-dragging. We construct the phase diagram of currently known zero-temperature vacuum black hole solutions with a single event horizon, and discuss the non-uniqueness introduced by more exotic black hole configurations such as bi-rings and multi-ring saturns.

  10. BLACK HISTORY MONTH

    Broader source: Energy.gov [DOE]

    Black History Month is an annual celebration of achievements by black Americans and a time for recognizing the central role of African Americans in U.S. history. The event grew out of “Negro History Week,” created by historian Carter G. Woodson and other prominent African Americans. Other countries around the world, including Canada and the United Kingdom, also devote a month to celebrating black history.

  11. Accreting Black Holes

    E-Print Network [OSTI]

    Begelman, Mitchell C

    2014-01-01

    I outline the theory of accretion onto black holes, and its application to observed phenomena such as X-ray binaries, active galactic nuclei, tidal disruption events, and gamma-ray bursts. The dynamics as well as radiative signatures of black hole accretion depend on interactions between the relatively simple black-hole spacetime and complex radiation, plasma and magnetohydrodynamical processes in the surrounding gas. I will show how transient accretion processes could provide clues to these interactions. Larger global magnetohydrodynamic simulations as well as simulations incorporating plasma microphysics and full radiation hydrodynamics will be needed to unravel some of the current mysteries of black hole accretion.

  12. Paradox Farm cold climate greenhouse Photo: Sue Wika Section I: Introduction

    E-Print Network [OSTI]

    Minnesota, University of

    #12;#12;Contents Paradox Farm cold climate greenhouse Photo: Sue Wika Contents Section I Towards the Sun 17 Site and Space Planning 19 Documentation and Monitoring 21 Section III: Greenhouse Components Greenhouse Components 23 Foundations 24 Soil and Containers 25 Greenhouse Frames 27 Light

  13. The St. Petersburg Paradox and the Crash of High-Tech Stocks in 2000

    E-Print Network [OSTI]

    Richards, Donald St. P.

    . P. RICHARDS During the late 1990s high technology growth stock prices were raised to unprecedented in which the valuation of growth stocks is related to the St. Petersburg paradox. Our conclusion- ball team; Fair game of chance; Geometric distribution; High technology stocks; Irrational exuberance

  14. BARRY LOEWER AND MARVIN BELZER HELP FOR THE GOOD SAMARITAN PARADOX

    E-Print Network [OSTI]

    Loewer, Barry

    with in this way. The "parad6x of the knower''4 goes like this: If Arabella is going to commit a murder FOR THE GOOD SAMARITAN PARADOX 119 murder. It seems to follow that Columbo ought to know that Arabella will commit a murder. Up to this point the best representation of the story in SDL seems to be: m-~ OKra, m

  15. Buffed energy landscapes: Another solution to the kinetic paradoxes of protein folding

    E-Print Network [OSTI]

    Plotkin, Steven S.

    Buffed energy landscapes: Another solution to the kinetic paradoxes of protein folding Steven S, February 6, 2003 The energy landscapes of proteins have evolved to be different from most random structure that is stable at biological temperatures leads to energy landscapes having a single dominant

  16. Megascience and the Powers and Paradoxes of Pushing Frontiers at Fermilab

    ScienceCinema (OSTI)

    Hoddeson, Lillian [University of Illinois, Champaign, Illinois, United States

    2009-09-01

    To help begin the year of celebration of Fermilab's fortieth anniversary (June 15, 1967), this colloquium will characterize the special brand of bigger 'Big Science' that emerged at Fermilab under Robert R. Wilson and Leon M. Lederman, with attention not only to its powers and beauties but to some of its paradoxes, conflicts, and ironies, due in part to funding limitations.

  17. Rotating Hairy Black Holes

    E-Print Network [OSTI]

    B. Kleihaus; J. Kunz

    2000-12-20

    We construct stationary black holes in SU(2) Einstein-Yang-Mills theory, which carry angular momentum and electric charge. Possessing non-trivial non-abelian magnetic fields outside their regular event horizon, they represent non-perturbative rotating hairy black holes.

  18. "Hybrid" Black Holes

    E-Print Network [OSTI]

    Valeri P. Frolov; Andrei V. Frolov

    2014-12-30

    We discuss a solution of the Einstein equations, obtained by gluing the external Kerr metric and the internal Weyl metric, describing an axisymmetric static vacuum distorted black hole. These metrics are glued at the null surfaces representing their horizons. For this purpose we use the formalism of massive thin null shells. The corresponding solution is called a "hybrid" black hole. The massive null shell has an angular momentum which is the origin of the rotation of the external Kerr spacetime. At the same time, the shell distorts the geometry inside the horizon. The inner geometry of the "hybrid" black hole coincides with the geometry of the interior of a non-rotating Weyl-distorted black hole. Properties of the "hybrid" black holes are briefly discussed.

  19. Exploring the isopycnal mixing and helium–heat paradoxes in a suite of Earth system models

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Gnanadesikan, A.; Pradal, M.-A.; Abernathey, R.

    2015-07-27

    This paper uses a suite of Earth system models which simulate the distribution of He isotopes and radiocarbon to examine two paradoxes in Earth science, each of which results from an inconsistency between theoretically motivated global energy balances and direct observations. The helium–heat paradox refers to the fact that helium emissions to the deep ocean are far lower than would be expected given the rate of geothermal heating, since both are thought to be the result of radioactive decay in Earth's interior. The isopycnal mixing paradox comes from the fact that many theoretical parameterizations of the isopycnal mixing coefficient ARedimore »that link it to baroclinic instability project it to be small (of order a few hundred m2 s?1) in the ocean interior away from boundary currents. However, direct observations using tracers and floats (largely in the upper ocean) suggest that values of this coefficient are an order of magnitude higher. Helium isotopes equilibrate rapidly with the atmosphere and thus exhibit large gradients along isopycnals while radiocarbon equilibrates slowly and thus exhibits smaller gradients along isopycnals. Thus it might be thought that resolving the isopycnal mixing paradox in favor of the higher observational estimates of ARedi might also solve the helium paradox, by increasing the transport of mantle helium to the surface more than it would radiocarbon. In this paper we show that this is not the case. In a suite of models with different spatially constant and spatially varying values of ARedi the distribution of radiocarbon and helium isotopes is sensitive to the value of ARedi. However, away from strong helium sources in the southeastern Pacific, the relationship between the two is not sensitive, indicating that large-scale advection is the limiting process for removing helium and radiocarbon from the deep ocean. The helium isotopes, in turn, suggest a higher value of ARedi below the thermocline than is seen in theoretical parameterizations based on baroclinic growth rates. We argue that a key part of resolving the isopycnal mixing paradox is to abandon the idea that ARedi has a direct relationship to local baroclinic instability and to the so-called "thickness" mixing coefficient AGM.« less

  20. PURDUE UNIVERSITY BLACK CULTURAL CENTER

    E-Print Network [OSTI]

    Pittendrigh, Barry

    traveled to Detroit, Michigan to study our fall research theme, " Black Detroit: The History, Movement

  1. Black Holes and Galaxy Evolution

    E-Print Network [OSTI]

    David Merritt

    1999-10-29

    Supermassive binary black holes and their influence on the structure and evolution of galaxies is reviewed.

  2. Renewable Electric Plant Information System user interface manual: Paradox 7 Runtime for Windows

    SciTech Connect (OSTI)

    1996-11-01

    The Renewable Electric Plant Information System (REPiS) is a comprehensive database with detailed information on grid-connected renewable electric plants in the US. The current version, REPiS3 beta, was developed in Paradox for Windows. The user interface (UI) was developed to facilitate easy access to information in the database, without the need to have, or know how to use, Paradox for Windows. The UI is designed to provide quick responses to commonly requested sorts of the database. A quick perusal of this manual will familiarize one with the functions of the UI and will make use of the system easier. There are six parts to this manual: (1) Quick Start: Instructions for Users Familiar with Database Applications; (2) Getting Started: The Installation Process; (3) Choosing the Appropriate Report; (4) Using the User Interface; (5) Troubleshooting; (6) Appendices A and B.

  3. Cold black holes in the Harlow–Hayden approach to firewalls

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ong, Yen Chin; McInnes, Brett; Chen, Pisin

    2014-12-31

    Firewalls are controversial principally because they seem to imply departures from general relativistic expectations in regions of spacetime where the curvature need not be particularly large. One of the virtues of the Harlow–Hayden approach to the firewall paradox, concerning the time available for decoding of Hawking radiation emanating from charged AdS black holes, is precisely that it operates in the context of cold black holes, which are not strongly curved outside the event horizon. Here we clarify this point. The approach is based on ideas borrowed from applications of the AdS/CFT correspondence to the quark–gluon plasma. Firewalls aside, our workmore »presents a detailed analysis of the thermodynamics and evolution of evaporating charged AdS black holes with flat event horizons. We show that, in one way or another, these black holes are always eventually destroyed in a time which, while long by normal standards, is short relative to the decoding time of Hawking radiation.« less

  4. Cold black holes in the Harlow–Hayden approach to firewalls

    SciTech Connect (OSTI)

    Ong, Yen Chin [Stockholm Univ., Stockholm (Sweden); National Taiwan Univ., Taipei (Taiwan); McInnes, Brett [National Univ. of Singapore (Singapore); Chen, Pisin [National Taiwan Univ., Taipei (Taiwan); SLAC National Accelerator Laboratory, Stanford, CA (United States)

    2014-12-31

    Firewalls are controversial principally because they seem to imply departures from general relativistic expectations in regions of spacetime where the curvature need not be particularly large. One of the virtues of the Harlow–Hayden approach to the firewall paradox, concerning the time available for decoding of Hawking radiation emanating from charged AdS black holes, is precisely that it operates in the context of cold black holes, which are not strongly curved outside the event horizon. Here we clarify this point. The approach is based on ideas borrowed from applications of the AdS/CFT correspondence to the quark–gluon plasma. Firewalls aside, our work presents a detailed analysis of the thermodynamics and evolution of evaporating charged AdS black holes with flat event horizons. We show that, in one way or another, these black holes are always eventually destroyed in a time which, while long by normal standards, is short relative to the decoding time of Hawking radiation.

  5. Black Holes In Astronomy Black Holes In Astronomy

    E-Print Network [OSTI]

    Wagner, Stephan

    Black Hole horizon static limit ergosphere radiation magnetic fields jet jet #12;Black-hole accretion with a central bulge. #12;Click to edit Master text styles Second level Third level Fourth level Fifth level Jets and lobes of Cygnus A Carilli et al. Supermassive black holes are the most powerful engines in the Universe

  6. The renaissance of black phosphorus

    E-Print Network [OSTI]

    Ling, Xi

    One hundred years after its first successful synthesis in the bulk form in 1914, black phosphorus (black P) was recently rediscovered from the perspective of a 2D layered material, attracting tremendous interest from ...

  7. Black Holes And Their Entropy 

    E-Print Network [OSTI]

    Mei, Jianwei

    2010-10-12

    . . . . . . . . . 21 1. Solutions in Four Dimensions . . . . . . . . . . . . . . 22 2. Solutions in Higher Dimensions . . . . . . . . . . . . . 27 C. Black Hole Solutions in Supergravity Theories . . . . . . . 30 D. Plebanski-Demianski Type Solutions in d = 5... is to discuss the construction of new black hole solutions and the calculation of the black hole entropy. In Chapter II, we shall re- port some new black hole solutions that we have found during the past few years [21, 22, 23] and we will discuss some...

  8. A model that solves to the wave-particle duality paradox

    E-Print Network [OSTI]

    Eduardo V. Flores

    2014-10-13

    Bohmian mechanics solves the wave-particle duality paradox by introducing the concept of a physical particle that is always point-like and a separate wavefunction with some sort of physical reality. However, this model has not been satisfactorily extended to relativistic levels. Here we introduce a model of permanent point-like particles that works at any energy level. Our model seems to have the benefits of Bohmian mechanics without its shortcomings. We propose an experiment for which the standard interpretation of quantum mechanics and our model make different predictions.

  9. Western consciousness, absurdity, and rebellion: the influence of paradox in the early works of Albert Camus 

    E-Print Network [OSTI]

    Lanier, Clinton David

    1994-01-01

    comes from the Greek word paradoxon with the roots para, which means "contrary to, " and doza, which means "opinion. " To state it simply, paradox is defined as a statement which is contrary to accepted opinion. This simple definition has evolved over... valuable and enduring lessons. "' In 1914, Camus's father was drafted into the French army and was killed in the first battle of the Marne. Camus's mother moved herself and her two sons, Lucien, the eldest, and Albert, to the working-class district...

  10. Increased Oil Production and Reserves Utilizing Secondary/Tertiary Recovery Techniques on Small Reservoirs in the Paradox Basin, Utah

    SciTech Connect (OSTI)

    Chidsey Jr., Thomas C.

    2003-02-06

    The primary objective of this project was to enhance domestic petroleum production by field demonstration and technology transfer of an advanced-oil-recovery technology in the Paradox Basin, southeastern Utah. If this project can demonstrate technical and economic feasibility, the technique can be applied to approximately 100 additional small fields in the Paradox Basin alone, and result in increased recovery of 150 to 200 million barrels (23,850,000-31,800,000 m3) of oil. This project was designed to characterize five shallow-shelf carbonate reservoirs in the Pennsylvanian (Desmoinesian) Paradox Formation and choose the best candidate for a pilot demonstration project for either a waterflood or carbon-dioxide-(CO2-) miscible flood project. The field demonstration, monitoring of field performance, and associated validation activities will take place within the Navajo Nation, San Juan County, Utah.

  11. Black Holes at Accelerators

    E-Print Network [OSTI]

    Bryan Webber

    2006-04-06

    In theories with large extra dimensions and TeV-scale gravity, black holes are copiously produced in particle collisions at energies well above the Planck scale. I briefly review some recent work on the phenomenology of this process, with emphasis on theoretical uncertainties and possible strategies for measuring the number of extra dimensions.

  12. Quantum black hole inflation

    E-Print Network [OSTI]

    M. B. Altaie

    2001-05-07

    In this paper we follow a new approach for particle creation by a localized strong gravitational field. The approach is based on a definition of the physical vacuum drawn from Heisenberg uncertainty principle. Using the fact that the gravitational field red-shifts the frequency modes of the vacuum, a condition on the minimum stregth of the gravitational field required to achieve real particle creation is derived. Application of this requirement on a Schwartzchid black hole resulted in deducing an upper limit on the region, outside the event horizon, where real particles can be created. Using this regional upper limit, and considering particle creation by black holes as a consequence of the Casimir effect, with the assumption that the created quanta are to be added to the initial energy, we deduce a natural power law for the development of the event horizon, and consequently a logarithmic law for the area spectrum of an inflating black hole. Application of the results on a cosmological model shows that if we start with a Planck-dimensional black hole, then through the process of particle creation we end up with a universe having the presently estimated critical density. Such a universe will be in a state of eternal inflation.

  13. Gasification of black liquor

    DOE Patents [OSTI]

    Kohl, Arthur L. (Woodland Hills, CA)

    1987-07-28

    A concentrated aqueous black liquor containing carbonaceous material and alkali metal sulfur compounds is treated in a gasifier vessel containing a relatively shallow molten salt pool at its bottom to form a combustible gas and a sulfide-rich melt. The gasifier vessel, which is preferably pressurized, has a black liquor drying zone at its upper part, a black liquor solids gasification zone located below the drying zone, and a molten salt sulfur reduction zone which comprises the molten salt pool. A first portion of an oxygen-containing gas is introduced into the gas space in the gasification zone immediatley above the molten salt pool. The remainder of the oxygen-containing gas is introduced into the molten salt pool in an amount sufficient to cause gasification of carbonaceous material entering the pool from the gasification zone but not sufficient to create oxidizing conditions in the pool. The total amount of the oxygen-containing gas introduced both above the pool and into the pool constitutes between 25 and 55% of the amount required for complete combustion of the black liquor feed. A combustible gas is withdrawn from an upper portion of the drying zone, and a melt in which the sulfur content is predominantly in the form of alkali metal sulfide is withdrawn from the molten salt sulfur reduction zone.

  14. Gasification of black liquor

    DOE Patents [OSTI]

    Kohl, A.L.

    1987-07-28

    A concentrated aqueous black liquor containing carbonaceous material and alkali metal sulfur compounds is treated in a gasifier vessel containing a relatively shallow molten salt pool at its bottom to form a combustible gas and a sulfide-rich melt. The gasifier vessel, which is preferably pressurized, has a black liquor drying zone at its upper part, a black liquor solids gasification zone located below the drying zone, and a molten salt sulfur reduction zone which comprises the molten salt pool. A first portion of an oxygen-containing gas is introduced into the gas space in the gasification zone immediately above the molten salt pool. The remainder of the oxygen-containing gas is introduced into the molten salt pool in an amount sufficient to cause gasification of carbonaceous material entering the pool from the gasification zone but not sufficient to create oxidizing conditions in the pool. The total amount of the oxygen-containing gas introduced both above the pool and into the pool constitutes between 25 and 55% of the amount required for complete combustion of the black liquor feed. A combustible gas is withdrawn from an upper portion of the drying zone, and a melt in which the sulfur content is predominantly in the form of alkali metal sulfide is withdrawn from the molten salt sulfur reduction zone. 2 figs.

  15. To label or not to label, the GMO food paradox Is labeling of foods containing GMOs a consumer right? Or does labeling of GMO

    E-Print Network [OSTI]

    Ciocan-Fontanine, Ionut

    To label or not to label, the GMO food paradox Is labeling of foods containing GMOs a consumer right? Or does labeling of GMO foods create a false warning? Are voluntary initiatives sufficient and government agencies? As States and the nation grapple with the GMO labeling paradox, the Finding Common

  16. Statistical Mechanics of Black Holes

    E-Print Network [OSTI]

    B. Harms; Y. Leblanc

    1992-05-11

    We analyze the statistical mechanics of a gas of neutral and charged black holes. The microcanonical ensemble is the only possible approach to this system, and the equilibrium configuration is the one for which most of the energy is carried by a single black hole. Schwarzschild black holes are found to obey the statistical bootstrap condition. In all cases, the microcanonical temperature is identical to the Hawking temperature of the most massive black hole in the gas. U(1) charges in general break the bootstrap property. The problems of black hole decay and of quantum coherence are also addressed.

  17. Identification of Astrophysical Black Holes

    E-Print Network [OSTI]

    Sandip K. Chakrabarti

    1998-03-19

    Black holes are by definition black, and therefore cannot be directly observed by using electromagnetic radiations. Convincing identification of black holes must necessarily depend on the identification of a very specially behaving matter and radiation which surround them. A major problem in this subject of black hole astrophysics is to quantify the behaviour of matter and radiation close to the horizon. In this review, the subject of black hole accretion and outflow is systematically developed. It is shown that both the stationary as well as the non-stationary properties of the observed spectra could be generally understood by these solutions. It is suggested that the solutions of radiative hydrodynamic equations may produce clear spectral signatures of black holes. Other circumstantial evidences of black holes, both in the galactic centers as well as in binary systems, are also presented.

  18. Black Hole Scan

    E-Print Network [OSTI]

    Juan Crisostomo; Ricardo Troncoso; Jorge Zanelli

    2000-09-22

    Gravitation theories selected by requiring that they have a unique anti-de Sitter vacuum with a fixed cosmological constant are studied. For a given dimension d, the Lagrangians under consideration are labeled by an integer k=1,2,...,[(d-1)/2]. Black holes for each d and k are found and are used to rank these theories. A minimum possible size for a localized electrically charged source is predicted in the whole set of theories, except General Relativity. It is found that the thermodynamic behavior falls into two classes: If d-2k=1, these solutions resemble the three dimensional black hole, otherwise, their behavior is similar to the Schwarzschild-AdS_4 geometry.

  19. Black holes at accelerators.

    E-Print Network [OSTI]

    Webber, Bryan R

    be presented and the effects of some of the uncertainties can be investigated. 3.1. Hawking Spectrum With the above assumptions, the spectrum of particles emitted during black hole decay takes the form dN dE ? ?E2 (eE/TH ? 1) T n+6H (8) where as usual... the trapped surface area [6, 7]. T030 02 4 6 8 10 0 0.2 0.4 0.6 0.8 1 1.2 n=0 n=1 n=2 n=6 E rS ?ˆ (0 ) ab s/ pi r2 S Figure 4: Grey-body factors for scalar emission on the brane from a (4 + n)D black hole. 0 2 4 6 8 10 0 0.2 0.4 0.6 0.8 1 1.2 n=0 n=1 n=2 n=6 E...

  20. Black Pine Circle Project

    SciTech Connect (OSTI)

    Mytko, Christine

    2014-03-31

    A group of seventh graders from Black Pine Circle school in Berkeley had the opportunity to experience the Advanced Light Source (ALS) as "users" via a collaborative field trip and proposal project. The project culminated with a field trip to the ALS for all seventh graders, which included a visit to the ALS data visualization room, a diffraction demonstration, a beamline tour, and informative sessions about x-rays and tomography presented by ALS scientists.

  1. Black Pine Circle Project

    ScienceCinema (OSTI)

    Mytko, Christine

    2014-09-15

    A group of seventh graders from Black Pine Circle school in Berkeley had the opportunity to experience the Advanced Light Source (ALS) as "users" via a collaborative field trip and proposal project. The project culminated with a field trip to the ALS for all seventh graders, which included a visit to the ALS data visualization room, a diffraction demonstration, a beamline tour, and informative sessions about x-rays and tomography presented by ALS scientists.

  2. Black Hole Demographics

    E-Print Network [OSTI]

    Laura Ferrarese

    2002-03-04

    The purpose of this contribution is to review the current status of black hole demographics in light of recent advances in the study of high redshift QSOs (section 2), local AGNs (section 3) and local quiescent galaxies (section 4). I will then outline the prospects for future progress (section 5), and discuss what I believe will be the challenges for the years to come [ABRIDGED].

  3. Generated using version 3.2 of the official AMS LATEX template Slippery thermals and the cumulus entrainment paradox1

    E-Print Network [OSTI]

    Sherwood, Steven

    entrainment paradox1 Steven C. Sherwood, Daniel Hern´andez-Deckers, and Maxime Colin Climate Change Research of momentum dilution for cumulus development are explored using a16 simple model of a heterogeneous entraining parcel. Without friction, parcels reach the upper17 troposphere even at a high entrainment rates ( (2 km

  4. Black holes in general relativity

    E-Print Network [OSTI]

    Visser, Matt

    2009-01-01

    What is going on (as of August 2008) at the interface between theoretical general relativity, string-inspired models, and observational astrophysics? Quite a lot. In this mini-survey I will make a personal choice and focus on four specific questions: Do black holes "exist"? (For selected values of the word "exist".) Is black hole formation and evaporation unitary? Can one mimic a black hole to arbitrary accuracy? Can one detect the presence of a horizon using local physics?

  5. Quantum Mechanics and Black Holes

    E-Print Network [OSTI]

    Jose N. Pecina-Cruz

    2005-11-27

    This paper discusses the existence of black holes from the foundations of quantum mechanics. It is found that quantum mechanics rule out a possible gravitational collapse.

  6. The Faint Young Sun Paradox in the Context of Modern Cosmology

    E-Print Network [OSTI]

    Dumin, Yurii V

    2015-01-01

    The Faint Young Sun Paradox comes from the fact that solar luminosity (2-4)x10^9 years ago was insufficient to support the Earth's temperature necessary for the efficient development of geological and biological evolution (particularly, for the existence of considerable volumes of liquid water). It remains unclear by now if the so-called greenhouse effect on the Earth can resolve this problem. An interesting alternative explanation was put forward recently by M.Krizek (New Ast. 2012, 17, 1), who suggested that planetary orbits expand with time due to the local Hubble effect, caused by the uniformly-distributed Dark Energy. Then, under a reasonable value of the local Hubble constant, it is easy to explain why the Earth was receiving an approximately constant amount of solar irradiation for a long period in the past and will continue to do so for a quite long time in future.

  7. Why Blue-Collar Blacks Help Less

    E-Print Network [OSTI]

    Smith, Sandra Susan; Young, Kara Alexis

    2013-01-01

    Exclude Black Men from Blue-Collar Jobs. Berkeley, CA:How Black and Latino Blue Collar Workers Make Decisionsof Sample Respondents Blue-Collar Latinos Blue-Collar Black

  8. Dermoscopy of black-spot poison ivy

    E-Print Network [OSTI]

    Rader, Ryan K; Mu, Ruipu; Shi, Honglan; Stoecker, William V; Hinton, Kristen A

    2012-01-01

    CT, Bean AS. Black-spot poison ivy: A rare phenomenon. J AmJG, Lucky AW. Black spot poison ivy: A report of 5 cases andis unique for black-spot poison ivy. The UFLC-MS/MS urushiol

  9. Green, Black, Lean Six Sigma and Master Black Belt Certifications

    E-Print Network [OSTI]

    Grissino-Mayer, Henri D.

    Green, Black, Lean Six Sigma and Master Black Belt Certifications Green BeLt CertifiCation Candidates may choose from three Green Belts offered: 1) Lean (one week of coursework) 2) Lean Six Sigma (two weeks of coursework) 3) Six Sigma (two weeks of coursework) Green Belt certification is a two

  10. Thermal BEC black holes

    E-Print Network [OSTI]

    Roberto Casadio; Andrea Giugno; Octavian Micu; Alessio Orlandi

    2015-11-04

    We review some features of BEC models of black holes obtained by means of the HWF formalism. We consider the KG equation for a toy graviton field coupled to a static matter current in spherical symmetry. The classical field reproduces the Newtonian potential generated by the matter source, while the corresponding quantum state is given by a coherent superposition of scalar modes with continuous occupation number. An attractive self-interaction is needed for bound states to form, so that (approximately) one mode is allowed, and the system of N bosons can be self-confined in a volume of the size of the Schwarzschild radius. The HWF is then used to show that the radius of such a system corresponds to a proper horizon. The uncertainty in the size of the horizon is related to the typical energy of Hawking modes: it decreases with the increasing of the black hole mass (larger number of gravitons), in agreement with semiclassical calculations and different from a single very massive particle. The spectrum contains a discrete ground state of energy $m$ (the bosons forming the black hole), and a continuous spectrum with energy $\\omega > m$ (representing the Hawking radiation and modelled with a Planckian distribution at the expected Hawking temperature). The $N$-particle state can be collectively described by a single-particle wave-function given by a superposition of a total ground state with energy $M = N m$ and a Planckian distribution for $E > M$ at the same Hawking temperature. The partition function is then found to yield the usual area law for the entropy, with a logarithmic correction related with the Hawking component. The backreaction of modes with $\\omega > m$ is also shown to reduce the Hawking flux and the evaporation properly stops for vanishing mass.

  11. Holographic Black Hole Chemistry

    E-Print Network [OSTI]

    Andreas Karch; Brandon Robinson

    2015-11-02

    Thermodynamic quantities associated with black holes in Anti-de Sitter space obey an interesting identity when the cosmological constant is included as one of the dynamical variables, the generalized Smarr relation. We show that this relation can easily be understood from the point of view of the dual holographic field theory. It amounts to the simple statement that the extensive thermodynamic quantities of a large $N$ gauge theory only depend on the number of colors, $N$, via an overall factor of $N^2$.

  12. You Cannot Press Out the Black Hole

    E-Print Network [OSTI]

    Daisuke Ida; Takahiro Okamoto

    2012-01-03

    It is shown that a ball-shaped black hole region homeomorphic with D**n cannot be pressed out, along whichever axis penetrating the black hole region, into a black ring with a doughnut-shaped black hole region homeomorphic with S**1 x D**(n-1). A more general prohibition law for the change of the topology of black holes, including a version of no-bifurcation theorems for black holes, is given.

  13. Black Stars and Gamma Ray Bursts

    E-Print Network [OSTI]

    Tanmay Vachaspati

    2007-06-08

    Stars that are collapsing toward forming a black hole but are frozen near the Schwarzschild horizon are termed ``black stars''. Collisions of black stars, in contrast to black hole collisions, may be sources of gamma ray bursts, whose basic parameters are estimated quite simply and are found to be consistent with observed gamma ray bursts. Black star gamma ray bursts should be preceded by gravitational wave emission similar to that from the coalescence of black holes.

  14. Black Holes of Negative Mass

    E-Print Network [OSTI]

    R. B. Mann

    1997-05-06

    I demonstrate that, under certain circumstances, regions of negative energy density can undergo gravitational collapse into a black hole. The resultant exterior black hole spacetimes necessarily have negative mass and non-trivial topology. A full theory of quantum gravity, in which topology-changing processes take place, could give rise to such spacetimes.

  15. Strings, higher curvature corrections, and black holes

    E-Print Network [OSTI]

    Thomas Mohaupt

    2005-12-05

    We review old and recent results on subleading contributions to black hole entropy in string theory.

  16. Physics: the big black box Mirror conjecture

    E-Print Network [OSTI]

    Cavalieri, Renzo

    Physics: the big black box Math Mirror conjecture A look into the mirror (I) an overview of Mirror Symmetry #12;Physics: the big black box Math Mirror conjecture Outline 1 Physics: the big black box 2 Math Symmetry #12;Physics: the big black box Math Mirror conjecture A slogan Mirror Symmetry is a correspondence

  17. Black hole horizons Eric Gourgoulhon

    E-Print Network [OSTI]

    Gourgoulhon, Eric

    on a black hole: up to 42% of the mass-energy mc2 of accreted matter ! NB: thermonuclear reactions release: a very deep gravitational potential well Release of potential gravitational energy by accretion

  18. Thermodynamics of regular black hole

    E-Print Network [OSTI]

    Yun Soo Myung; Yong-Wan Kim; Young-Jai Park

    2008-09-21

    We investigate thermodynamics for a magnetically charged regular black hole (MCRBH), which comes from the action of general relativity and nonlinear electromagnetics, comparing with the Reissner-Norstr\\"om (RN) black hole in both four and two dimensions after dimensional reduction. We find that there is no thermodynamic difference between the regular and RN black holes for a fixed charge $Q$ in both dimensions. This means that the condition for either singularity or regularity at the origin of coordinate does not affect the thermodynamics of black hole. Furthermore, we describe the near-horizon AdS$_2$ thermodynamics of the MCRBH with the connection of the Jackiw-Teitelboim theory. We also identify the near-horizon entropy as the statistical entropy by using the AdS$_2$/CFT$_1$ correspondence.

  19. Black Holes and Nuclear Dynamics

    E-Print Network [OSTI]

    David Merritt

    2006-02-17

    Supermassive black holes inhabit galactic nuclei, and their presence influences in crucial ways the evolution of the stellar distribution. The low-density cores observed in bright galaxies are probably a result of black hole infall, while steep density cusps like those at the Galactic center are a result of energy exchange between stars moving in the gravitational field of the single black hole. Loss-cone dynamics are substantially more complex in galactic nuclei than in collisionally-relaxed systems like globular clusters due to the wider variety of possible geometries and orbital populations. The rate of star-black hole interactions has begun to be constrained through observations of energetic events associated with stellar tidal disruptions.

  20. Extracting information about the initial state from the black hole radiation

    E-Print Network [OSTI]

    Kinjalk Lochan; T. Padmanabhan

    2015-07-23

    The crux of the black hole information paradox is related to the fact that the complete information about the initial state of a quantum field in a collapsing spacetime is not available to future asymptotic observers, belying the expectations from a unitary quantum theory. We study the imprints of the initial quantum state, contained in the distortions of the black hole radiation from the thermal spectrum, which can be detected by the asymptotic observers. We identify the class of in-states which can be fully reconstructed from the information contained in the distortions at the semiclassical level. Even for the general in-state, we can uncover a specific amount of information about the initial state. For a large class of initial states, some specific observables defined in the initial Hilbert space are completely determined from the resulting final spectrum. These results suggest that a \\textit{classical} collapse scenario ignores this richness of information in the resulting spectrum and a consistent quantum treatment of the entire collapse process might allow us to retrieve all the information from the spectrum of the final radiation.

  1. Hagedorn String Thermodynamics in Curved Spacetimes and near Black Hole Horizons

    E-Print Network [OSTI]

    Thomas G. Mertens

    2015-06-25

    This thesis concerns the study of high-temperature string theory on curved backgrounds, generalizing the notions of Hagedorn temperature and thermal scalar to general backgrounds. Chapter 2 contains a review on string thermodynamics in flat space, setting the stage. Chapters 3 and 4 contain the detailed study of the random walk picture in a general curved background. Chapters 5 and 6 then apply this to Rindler space, the near-horizon approximation of a generic (uncharged) black hole. Chapters 7 and 8 contain a study of the AdS3 and BTZ WZW models where we study the thermal spectrum and the resulting random walk picture that emerges. Chapters 9 and 10 attempt to draw general conclusions from the study of the two specific examples earlier: we draw lessons on string thermodynamics in general and on (perturbative) string thermodynamics around black hole horizons. For the latter, we point out a possible link to the firewall paradox. Finally, chapter 11 contains a detailed discussion on the near-Hagedorn (and high-energy) stress tensor in a generic spacetime, the results of which are applied to provide a description of the Bekenstein-Hawking entropy in terms of long string equilibration.

  2. Black Boundary Lines: Race, Class and Gender among Black Undergraduate Students

    E-Print Network [OSTI]

    Morales, Erica

    2012-01-01

    C. 1994. Behind the Mule: Race and Class in African AmericanHarlemworld: Doing Race and Class in Contemporary BlackBlue-Chip Black: Race, Class and Status in the New Black

  3. Fishing in Black Holes

    E-Print Network [OSTI]

    A. Brotas

    2006-09-01

    The coordinate system $(\\bar{x},\\bar{t})$ defined by $r = 2m + K\\bar{x}- c K \\bar{t}$ and $t=\\bar{x}/cK - 1 /cK \\int_{r_a}^r (1- 2m/r + K^2)^{1/2} (1 - 2m/r)^{-1}dr$ allow us to write the Schwarzschild metric in the form: \\[ds^2=c^2 d\\bar{t}^2 + (W^2/K^2 - 2W/K) d\\bar{x}^2 + 2c (1 + W/K) d\\bar{x}d\\bar{t} - r^2 (d\\theta^2 + cos^2\\theta d\\phi^2)\\] with $W=(1 - 2m/r + K^2)^{1/2}$, in which the coefficients' pathologies are moved to $r_K = 2m/(1+K^2)$. This new coordinate system is used to study the entrance into a black hole of a rigid line (a line in which the shock waves propagate with velocity c).

  4. Quasi-normal modes: the "electrons" of black holes as "gravitational atoms"? Implications for the black hole information puzzle

    E-Print Network [OSTI]

    Christian Corda

    2015-03-31

    Some recent important results on black hole (BH) quantum physics concerning the BH effective state and the natural correspondence between Hawking radiation and BH quasi-normal modes (QNMs) are reviewed, clarified and refined. Such a correspondence permits to naturally interpret QNMs as quantum levels in a semi-classical model. This is a model of BH somewhat similar to the historical semi-classical model of the structure of a hydrogen atom introduced by Bohr in 1913. In a certain sense, QNMs represent the "electron" which jumps from a level to another one and the absolute values of the QNMs frequencies "triggered" by emissions (Hawking radiation) and absorption of particles represent the energy "shells" of the "gravitational hydrogen atom". Important consequences on the BH information puzzle are discussed. In fact, it is shown that the time evolution of this "Bohr-like BH model" obeys to a time dependent Schr\\"odinger equation which permits the final BH state to be a pure quantum state instead of a mixed one. Thus, information comes out in BH evaporation, in agreement with the assumption by 't Hooft that Schr\\"oedinger equations can be used universally for all dynamics in the universe. We also show that, in addition, our approach solves the entanglement problem connected with the information paradox. We emphasize that Bohr model is an approximated model of the hydrogen atom with respect to the valence shell atom model of full quantum mechanics. In the same way, we expect the Bohr-like BH model to be an approximated model with respect to the definitive, but at the present time unknown, BH model arising from a full quantum gravity theory.

  5. Black hole mimickers: Regular versus singular behavior

    SciTech Connect (OSTI)

    Lemos, Jose P. S.; Zaslavskii, Oleg B.

    2008-07-15

    Black hole mimickers are possible alternatives to black holes; they would look observationally almost like black holes but would have no horizon. The properties in the near-horizon region where gravity is strong can be quite different for both types of objects, but at infinity it could be difficult to discern black holes from their mimickers. To disentangle this possible confusion, we examine the near-horizon properties, and their connection with far away asymptotic properties, of some candidates to black mimickers. We study spherically symmetric uncharged or charged but nonextremal objects, as well as spherically symmetric charged extremal objects. Within the uncharged or charged but nonextremal black hole mimickers, we study nonextremal {epsilon}-wormholes on the threshold of the formation of an event horizon, of which a subclass are called black foils, and gravastars. Within the charged extremal black hole mimickers we study extremal {epsilon}-wormholes on the threshold of the formation of an event horizon, quasi-black holes, and wormholes on the basis of quasi-black holes from Bonnor stars. We elucidate whether or not the objects belonging to these two classes remain regular in the near-horizon limit. The requirement of full regularity, i.e., finite curvature and absence of naked behavior, up to an arbitrary neighborhood of the gravitational radius of the object enables one to rule out potential mimickers in most of the cases. A list ranking the best black hole mimickers up to the worst, both nonextremal and extremal, is as follows: wormholes on the basis of extremal black holes or on the basis of quasi-black holes, quasi-black holes, wormholes on the basis of nonextremal black holes (black foils), and gravastars. Since in observational astrophysics it is difficult to find extremal configurations (the best mimickers in the ranking), whereas nonextremal configurations are really bad mimickers, the task of distinguishing black holes from their mimickers seems to be less difficult than one could think of it.

  6. International black tea market integration and price discovery 

    E-Print Network [OSTI]

    Dharmasena, Kalu Arachchillage Senarath Dhananjaya Bandara

    2004-09-30

    In this thesis we study three basic issues related to international black tea markets: Are black tea markets integrated? Where is the price of black tea discovered? Are there leaders and followers in black tea markets? We ...

  7. Energy on black hole spacetimes

    E-Print Network [OSTI]

    Alejandro Corichi

    2012-07-18

    We consider the issue of defining energy for test particles on a background black hole spacetime. We revisit the different notions of energy as defined by different observers. The existence of a time-like isometry allows for the notion of a total conserved energy to be well defined, and subsequently the notion of a gravitational potential energy is also meaningful. We then consider the situation in which the test particle is adsorbed by the black hole, and analyze the energetics in detail. In particular, we show that the notion of horizon energy es defined by the isolated horizons formalism provides a satisfactory notion of energy compatible with the particle's conserved energy. As another example, we comment a recent proposal to define energy of the black hole as seen by an observer at rest. This account is intended to be pedagogical and is aimed at the level of and as a complement to the standard textbooks on the subject.

  8. Heat Engine of black holes

    E-Print Network [OSTI]

    J. Sadeghi; Kh. Jafarzade

    2015-06-23

    As we know, the cosmological constant in different theories of gravity acts as a thermodynamics variable. The cosmological constant exists in different actions of gravity and also appears in the solution of such theories. These lead to use the black hole as a heat engines. Also, there are two values for the cosmological constant as positive and negative values. The case of negative cosmological constant supplies a natural realization of these engines in terms of the field theory description of the fluids to which they are holographically dual. In this paper, we are going to define heat engines for two different black holes as Dyonic BH and Kerr BH. And also, we calculate maximum efficiency for two black holes.

  9. Charged rotating dilaton black strings

    SciTech Connect (OSTI)

    Dehghani, M.H.; Farhangkhah, N.

    2005-02-15

    In this paper we, first, present a class of charged rotating solutions in four-dimensional Einstein-Maxwell-dilaton gravity with zero and Liouville-type potentials. We find that these solutions can present a black hole/string with two regular horizons, an extreme black hole or a naked singularity provided the parameters of the solutions are chosen suitable. We also compute the conserved and thermodynamic quantities, and show that they satisfy the first law of thermodynamics. Second, we obtain the (n+1)-dimensional rotating solutions in Einstein-dilaton gravity with Liouville-type potential. We find that these solutions can present black branes, naked singularities or spacetimes with cosmological horizon if one chooses the parameters of the solutions correctly. Again, we find that the thermodynamic quantities of these solutions satisfy the first law of thermodynamics.

  10. Quantum Criticality and Black Holes

    ScienceCinema (OSTI)

    Sachdev, Subir [Harvard University, Cambridge, Massachusetts, United States

    2009-09-01

    I will describe the behavior of a variety of condensed matter systems in the vicinity of zero temperature quantum phase transitions. There is a remarkable analogy between the hydrodynamics of such systems and the quantum theory of black holes. I will show how insights from this analogy have shed light on recent experiments on the cuprate high temperature superconductors. Studies of new materials and trapped ultracold atoms are yielding new quantum phases, with novel forms of quantum entanglement. Some materials are of technological importance: e.g. high temperature superconductors. Exact solutions via black hole mapping have yielded first exact results for transport coefficients in interacting many-body systems, and were valuable in determining general structure of hydrodynamics. Theory of VBS order and Nernst effect in cuprates. Tabletop 'laboratories for the entire universe': quantum mechanics of black holes, quark-gluon plasma, neutrons stars, and big-bang physics.

  11. Black Holes and Galaxy Dynamics

    E-Print Network [OSTI]

    David Merritt

    1999-06-02

    The consequences of nuclear black holes for the structure and dynamics of stellar spheroids are reviewed. Slow growth of a black hole in a pre-existing core produces a steep power-law density profile similar to the cusps seen in faint elliptical galaxies. The weaker cusps in bright ellipticals may result from ejection of stars by a coalescing black-hole binary; there is marginal kinematical evidence for such a process having occurred in M87. Stellar orbits in a triaxial nucleus are mostly regular at radii where the gravitational force is dominated by the black hole; however the orbital shapes are not conducive to reinforcing the triaxial figure, hence nuclei are likely to be approximately axisymmetric. In triaxial potentials, a ``zone of chaos'' extends outward to a radius where the enclosed stellar mass is roughly 100 times the mass of the black hole; in this chaotic zone, no regular, box-like orbits exist. At larger radii, the phase space in triaxial potentials is complex, consisting of stochastic orbits as well as regular orbits associated with stable resonances. Figure rotation tends to increase the degree of stochasticity. Both test-particle integrations and N-body simulations suggest that a triaxial galaxy responds globally to the presence of a central mass concentration by evolving toward more axisymmetric shapes; the evolution occurs rapidly when the mass of the central object exceeds roughly 2% of the mass in stars. The lack of significant triaxiality in most early-type galaxies may be a consequence of orbital evolution induced by nuclear black holes.

  12. Radiation transport around Kerr black holes

    E-Print Network [OSTI]

    Schnittman, Jeremy David

    2005-01-01

    This Thesis describes the basic framework of a relativistic ray-tracing code for analyzing accretion processes around Kerr black holes. We begin in Chapter 1 with a brief historical summary of the major advances in black ...

  13. Does phantom energy produce black hole?

    E-Print Network [OSTI]

    F. Rahaman; A. Ghosh; M. Kalam

    2006-12-23

    We have found an exact solution of spherically symmetrical Einstein equations describing a black hole with a special type phantom energy source. It is surprising to note that our solution is analogous to Reissner-Nordstr\\"{o}m black hole.

  14. 4d neutral dilatonic black holes and (4+p) dimensional nondilatonic black p-branes

    E-Print Network [OSTI]

    J. R. Morris

    2000-01-11

    It is shown that, in contrast to the case of extreme 4d dilatonic black holes, 4d neutral dilatonic black holes with horizon singularities can not be interpreted as nonsingular nondilatonic black p-branes in (4+p) dimensions, regardless of the number of extra dimensions p. That is, extra dimensions do not remove naked singularities of 4d neutral dilatonic black holes.

  15. Increased oil production and reserves utilizing secondary/tertiary recovery techniques on small reservoirs in the Paradox Basin, Utah, Class II

    SciTech Connect (OSTI)

    Chidsey, Thomas C.

    2000-07-28

    The primary objective of this project is to enhance domestic petroleum production by field demonstration and technology transfer of an advanced-oil-recovery technology in the Paradox basin, southeastern Utah. If this project can demonstrate technical and economic feasibility, the technique can be applied to approximately 100 additional small fields in the Paradox basin alone, and result in increased recovery of 150 to 200 million barrels (23,850,000-31,800,000 m{sup 3}) of oil. This project is designed to characterize five shallow-shelf carbonate reservoirs in the Pennsylvanian (Desmoinesian) Paradox Formation and choose the best candidate for a pilot demonstration project for either a waterflood or carbon-dioxide-miscible flood project. The field demonstration, monitoring of field performance, and associated validation activities will take place within the Navajo Nation, San Juan County, Utah.

  16. Classical and thermodynamic stability of black holes

    E-Print Network [OSTI]

    Ricardo Monteiro

    2010-06-28

    We consider the stability of black holes within both classical general relativity and the semiclassical thermodynamic description. In particular, we study linearised perturbations and their contribution to the gravitational partition function, addressing technical issues for charged (Reissner-Nordstrom) and rotating (Kerr-AdS) black holes. Exploring the connection between classical and thermodynamic stability, we find classical instabilities of Myers-Perry black holes and bifurcations to new black hole families.

  17. Will black holes eventually engulf the universe?

    E-Print Network [OSTI]

    Prado Martin-Moruno; Jose A. Jimenez Madrid; Pedro F. Gonzalez-Diaz

    2006-03-28

    The Babichev-Dokuchaev-Eroshenko model for the accretion of dark energy onto black holes has been extended to deal with black holes with non-static metrics. The possibility that for an asymptotic observer a black hole with large mass will rapidly increase and eventually engulf the Universe at a finite time in the future has been studied by using reasonable values for astronomical parameters. It is concluded that such a phenomenon is forbidden for all black holes in quintessential cosmological models.

  18. Hawking Emission and Black Hole Thermodynamics

    E-Print Network [OSTI]

    Don N. Page

    2006-12-18

    A brief review of Hawking radiation and black hole thermodynamics is given, based largely upon hep-th/0409024.

  19. Warrior Girl Corporation | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page| Open Energy Information Serbia-EnhancingEt Al.,Turin,VillageWarren Park, Indiana: EnergyWarrick County,

  20. Scattering by regular black holes: Planar massless scalar waves impinging upon a Bardeen black hole

    E-Print Network [OSTI]

    Macedo, Caio F B; Crispino, Luís C B

    2015-01-01

    Singularities are common features of general relativity black holes. However, within general relativity, one can construct black holes that present no singularities. These regular black hole solutions can be achieved by, for instance, relaxing one of the energy conditions on the stress energy tensor sourcing the black hole. Some regular black hole solutions were found in the context of non-linear electrodynamics, the Bardeen black hole being the first one proposed. In this paper, we consider a planar massless scalar wave scattered by a Bardeen black hole. We compare the scattering cross section computed using a partial-wave description with the classical geodesic scattering of a stream of null geodesics, as well as with the semi-classical glory approximation. We obtain that, for some values of the corresponding black hole charge, the scattering cross section of a Bardeen black hole has a similar interference pattern of a Reissner-Nordstr\\"om black hole.

  1. Scattering by regular black holes: Planar massless scalar waves impinging upon a Bardeen black hole

    E-Print Network [OSTI]

    Caio F. B. Macedo; Ednilton S. de Oliveira; Luís C. B. Crispino

    2015-06-26

    Singularities are common features of general relativity black holes. However, within general relativity, one can construct black holes that present no singularities. These regular black hole solutions can be achieved by, for instance, relaxing one of the energy conditions on the stress energy tensor sourcing the black hole. Some regular black hole solutions were found in the context of non-linear electrodynamics, the Bardeen black hole being the first one proposed. In this paper, we consider a planar massless scalar wave scattered by a Bardeen black hole. We compare the scattering cross section computed using a partial-wave description with the classical geodesic scattering of a stream of null geodesics, as well as with the semi-classical glory approximation. We obtain that, for some values of the corresponding black hole charge, the scattering cross section of a Bardeen black hole has a similar interference pattern of a Reissner-Nordstr\\"om black hole.

  2. New approaches to black holes Eric Gourgoulhon

    E-Print Network [OSTI]

    Gourgoulhon, Eric

    References Eric Gourgoulhon (LUTH) New approaches to black holes Okinawa Nat. Col. Tech., 17 Aug 2008 2 / 36 Gourgoulhon (LUTH) New approaches to black holes Okinawa Nat. Col. Tech., 17 Aug 2008 3 / 36 #12;Local (2006)] Eric Gourgoulhon (LUTH) New approaches to black holes Okinawa Nat. Col. Tech., 17 Aug 2008 4

  3. From Pinholes to Black Holes

    SciTech Connect (OSTI)

    Fenimore, Edward E.

    2014-10-06

    Pinhole photography has made major contributions to astrophysics through the use of “coded apertures”. Coded apertures were instrumental in locating gamma-ray bursts and proving that they originate in faraway galaxies, some from the birth of black holes from the first stars that formed just after the big bang.

  4. Extremal Higher Spin Black Holes

    E-Print Network [OSTI]

    Máximo Bañados; Alejandra Castro; Alberto Faraggi; Juan I. Jottar

    2015-11-30

    The gauge sector of three-dimensional higher spin gravities can be formulated as a Chern-Simons theory. In this context, a higher spin black hole corresponds to a flat connection with suitable holonomy (smoothness) conditions which are consistent with the properties of a generalized thermal ensemble. Building on these ideas, we discuss a definition of black hole extremality which is appropriate to the topological character of 3d higher spin theories. Our definition can be phrased in terms of the Jordan class of the holonomy around a non-contractible (angular) cycle, and we show that it is compatible with the zero-temperature limit of smooth black hole solutions. While this notion of extremality does not require nor implies the existence of supersymmetry, we exemplify its consequences in the context of sl(3|2) + sl(3|2) Chern-Simons theory. Remarkably, while as usual not all extremal solutions preserve supersymmetries, we find that the higher spin setup allows for non-extremal supersymmetric black hole solutions as well. Furthermore, we discuss our results from the perspective of the holographic duality between sl(3|2) + sl(3|2) Chern-Simons theory and two-dimensional CFTs with W_{(3|2)} symmetry, the simplest higher spin extension of the N=2 super-Virasoro algebra. In particular, we compute W_{(3|2)} BPS bounds at the full quantum level, and relate their semiclassical limit to extremal black hole or conical defect solutions in the 3d bulk. Along the way, we discuss the role of the spectral flow automorphism and provide a conjecture for the form of the semiclassical BPS bounds in general N=2 two-dimensional CFTs with extended symmetry algebras.

  5. Black hole microstates in AdS

    E-Print Network [OSTI]

    Shaghoulian, Edgar

    2015-01-01

    We extend a recently derived higher-dimensional Cardy formula to include angular momenta, which we use to obtain the Bekensten-Hawking entropy of AdS black branes, compactified rotating branes, and large Schwarzschild/Kerr black holes. This is the natural generalization of Strominger's microscopic derivation of the BTZ black hole entropy to higher dimensions. We propose an extension to include $U(1)$ charge, which agrees with the Bekenstein-Hawking entropy of large Reissner-Nordstrom/Kerr-Newman black holes at high temperature. We extend the results to arbitrary hyperscaling violation exponent (this captures the case of black D$p$-branes as a subclass) and reproduce logarithmic corrections.

  6. Holographic Thermalization, stability of AdS, and the Fermi-Pasta-Ulam-Tsingou paradox

    E-Print Network [OSTI]

    Venkat Balasubramanian; Alex Buchel; Stephen R. Green; Luis Lehner; Steven L. Liebling

    2014-06-16

    For a real massless scalar field in general relativity with a negative cosmological constant, we uncover a large class of spherically symmetric initial conditions that are close to AdS, but whose numerical evolution does not result in black hole formation. According to the AdS/CFT dictionary, these bulk solutions are dual to states of a strongly interacting boundary CFT that fail to thermalize at late times. Furthermore, as these states are not stationary, they define dynamical CFT configurations that do not equilibrate. We develop a two-timescale perturbative formalism that captures both direct and inverse cascades of energy and agrees with our fully nonlinear evolutions in the appropriate regime. We also show that this formalism admits a large class of quasi-periodic solutions. Finally, we demonstrate a striking parallel between the dynamics of AdS and the classic Fermi-Pasta-Ulam-Tsingou problem.

  7. Black Hole Thermodynamics and Electromagnetism

    E-Print Network [OSTI]

    Burra G. Sidharth

    2005-07-15

    We show a strong parallel between the Hawking, Beckenstein black hole Thermodynamics and electromagnetism: When the gravitational coupling constant transform into the electromagnetic coupling constant, the Schwarzchild radius, the Beckenstein temperature, the Beckenstein decay time and the Planck mass transform to respectively the Compton wavelength, the Hagedorn temperature, the Compton time and a typical elementary particle mass. The reasons underlying this parallalism are then discussed in detail.

  8. Classical Black Holes Are Hot

    E-Print Network [OSTI]

    Erik Curiel

    2014-11-09

    In the early 1970s it is was realized that there is a striking formal analogy between the Laws of black-hole mechanics and the Laws of classical thermodynamics. Before the discovery of Hawking radiation, however, it was generally thought that the analogy was only formal, and did not reflect a deep connection between gravitational and thermodynamical phenomena. It is still commonly held that the surface gravity of a stationary black hole can be construed as a true physical temperature and its area as a true entropy only when quantum effects are taken into account; in the context of classical general relativity alone, one cannot cogently construe them so. Does the use of quantum field theory in curved spacetime offer the only hope for taking the analogy seriously? I think the answer is `no'. To attempt to justify that answer, I shall begin by arguing that the standard argument to the contrary is not physically well founded, and in any event begs the question. Looking at the various ways that the ideas of "temperature" and "entropy" enter classical thermodynamics then will suggest arguments that, I claim, show the analogy between classical black-hole mechanics and classical thermodynamics should be taken more seriously, without the need to rely on or invoke quantum mechanics. In particular, I construct an analogue of a Carnot cycle in which a black hole "couples" with an ordinary thermodynamical system in such a way that its surface gravity plays the role of temperature and its area that of entropy. Thus, the connection between classical general relativity and classical thermodynamics on their own is already deep and physically significant, independent of quantum mechanics.

  9. Relationship of Black Holes to Bulges

    E-Print Network [OSTI]

    David Merritt; Laura Ferrarese

    2001-07-08

    Supermassive black holes appear to be uniquely associated with galactic bulges. The mean ratio of black hole mass to bulge mass was until recently very uncertain, with ground based, stellar kinematical data giving a value roughly an order of magnitude larger than other techniques. The discrepancy was resolved with the discovery of the M-sigma relation, which simultaneously established a tight corrrelation between black hole mass and bulge velocity dispersion, and confirmed that the stellar kinematical mass estimates were systematically too large due to failure to resolve the black hole's sphere of influence. There is now excellent agreement between the various techniques for estimating the mean black hole mass, including dynamical mass estimation in quiescent galaxies; reverberation mapping in active galaxies and quasars; and computation of the mean density of compact objects based on integrated quasar light. Implications of the M-sigma relation for the formation of black holes are discussed.

  10. Boson shells harboring charged black holes

    SciTech Connect (OSTI)

    Kleihaus, Burkhard; Kunz, Jutta; Laemmerzahl, Claus; List, Meike

    2010-11-15

    We consider boson shells in scalar electrodynamics coupled to Einstein gravity. The interior of the shells can be empty space, or harbor a black hole or a naked singularity. We analyze the properties of these types of solutions and determine their domains of existence. We investigate the energy conditions and present mass formulae for the composite black hole-boson shell systems. We demonstrate that these types of solutions violate black hole uniqueness.

  11. Thermodynamic fluctuation in black string flow

    E-Print Network [OSTI]

    Meng Sun; Yong-Chang Huna

    2015-06-14

    It has long been noticed that Laudau-Lifshitz theory can be used to study the fluctuation of a system that contains a black hole. Since the black string can be constructed by extending n-dimensional black hole into one extra dimension. We study the fluctuation of black string flow with a Schwarzschlid-like metric in D=n+1 dimensional spacetime and a charged solution in D=5 dimensional spacetime and get the second moments of the fluctuation of the mass flux and charge flux.

  12. Thermodynamic fluctuation in black string flow

    E-Print Network [OSTI]

    Meng Sun; Yong-Chang Huang

    2015-05-11

    It has long been noticed that Laudau-Lifshitz theory can be used to study the fluctuation of a system that contains a black hole. Since the black string can be constructed by extending n-dimensional black hole into one extra dimension. We study the fluctuation of black string flow with a Schwarzschlid-like metric in D=n+1 dimensional spacetime and a charged solution in D=5 dimensional spacetime and get the second moments of the fluctuation of the mass flux and charge flux.

  13. Black carbon contribution to global warming

    SciTech Connect (OSTI)

    Chylek, P.; Johnson, B.; Kou, L.; Wong, J.

    1996-12-31

    Before the onset of industrial revolution the only important source of black carbon in the atmosphere was biomass burning. Today, black carbon production is divided between the biomass and fossil fuel burning. Black carbon is a major agent responsible for absorption of solar radiation by atmospheric aerosols. Thus black carbon makes other aerosols less efficient in their role of reflecting solar radiation and cooling the earth-atmosphere system. Black carbon also contributes to the absorption of solar radiation by clouds and snow cover. The authors present the results of black carbon concentrations measurements in the atmosphere, in cloud water, in rain and snow melt water collected during the 1992--1996 time period over the southern Nova Scotia. Their results are put into the global and historical perspective by comparing them with the compilation of past measurements at diverse locations and with their measurements of black carbon concentrations in the Greenland and Antarctic ice cores. Black carbon contribution to the global warming is estimated, and compared to the carbon dioxide warming, using the radiative forcing caused by the black carbon at the top of the atmosphere.

  14. Lower Dimensional Black Holes: Inside and Out

    E-Print Network [OSTI]

    R. B. Mann

    1995-01-27

    I survey the physics of black holes in two and three spacetime dimensions, with special attention given to an understanding of their exterior and interior properties.

  15. Black Holes: from Speculations to Observations

    E-Print Network [OSTI]

    Thomas W. Baumgarte

    2006-04-13

    This paper provides a brief review of the history of our understanding and knowledge of black holes. Starting with early speculations on ``dark stars'' I discuss the Schwarzschild "black hole" solution to Einstein's field equations and the development of its interpretation from "physically meaningless" to describing the perhaps most exotic and yet "most perfect" macroscopic object in the universe. I describe different astrophysical black hole populations and discuss some of their observational evidence. Finally I close by speculating about future observations of black holes with the new generation of gravitational wave detectors.

  16. Rotating Black Holes and Coriolis Effect

    E-Print Network [OSTI]

    Wu, Xiaoning; Yuan, Pei-Hung; Cho, Chia-Jui

    2015-01-01

    In this work, we consider the fluid/gravity correspondence for general rotating black holes. By using the Petrov-like boundary condition in near horizon limit, we study the correspondence between gravitational perturbation and fluid equation. We find that the dual fluid equation for rotating black holes contains a Coriolis force term, which is closely related to the angular velocity of the black hole horizon. This can be seen as a dual effect for the frame-dragging effect of rotating black hole under the holographic picture.

  17. Rotating Black Holes and Coriolis Effect

    E-Print Network [OSTI]

    Xiaoning Wu; Yi Yang; Pei-Hung Yuan; Chia-Jui Cho

    2015-11-27

    In this work, we consider the fluid/gravity correspondence for general rotating black holes. By using the Petrov-like boundary condition in near horizon limit, we study the correspondence between gravitational perturbation and fluid equation. We find that the dual fluid equation for rotating black holes contains a Coriolis force term, which is closely related to the angular velocity of the black hole horizon. This can be seen as a dual effect for the frame-dragging effect of rotating black hole under the holographic picture.

  18. L.A. Rebellion: Creating a New Black Cinema

    E-Print Network [OSTI]

    Sheppard, Samantha Noelle

    2011-01-01

    Creating a New Black Cinema Symposium Review by SamanthaCreating a New Black Cinema By the turn of the next century,in the development of Black cinema took place at UCLA in the

  19. Queering Black Gay Historiography: Performance, (Mis) Identifications, and Possibilities

    E-Print Network [OSTI]

    Fitzgerald, Thomas Howard

    2013-01-01

    In 1976 the black comedy Car Wash featured a black gay manthe a openly black sissy in the Car Wash as a character thatsaw the distribution of Car Wash with Antoino Fargas playing

  20. Extraordinary vacuum black string solutions

    SciTech Connect (OSTI)

    Kim, Hyeong-Chan; Lee, Jungjai

    2008-01-15

    In addition to the boosted static solution there are two other classes of stationary stringlike solutions of the vacuum Einstein equation in (4+1) dimensions. Each class is characterized by three parameters of mass, tension, and momentum flow along the fifth coordinate. We analyze the metric properties of one of the two classes, which was previously assumed to be naked singular, and show that the solution spectrum contains black string and wormhole in addition to the known naked singularity as the momentum flow to mass ratio increases. Interestingly, there does not exist new zero momentum solution in these cases.

  1. Effective theories and black hole production in warped compactificatio...

    Office of Scientific and Technical Information (OSTI)

    Effective theories and black hole production in warped compactifications Citation Details In-Document Search Title: Effective theories and black hole production in warped...

  2. An electromagnetic black hole made of metamaterials

    E-Print Network [OSTI]

    Qiang Cheng; Tie Jun Cui; Wei Xiang Jiang; Ben Geng Cai

    2010-04-30

    Traditionally, a black hole is a region of space with huge gravitational field, which absorbs everything hitting it. In history, the black hole was first discussed by Laplace under the Newton mechanics, whose event horizon radius is the same as the Schwarzschild's solution of the Einstein's vacuum field equations. If all those objects having such an event horizon radius but different gravitational fields are called as black holes, then one can simulate certain properties of the black holes using electromagnetic fields and metamaterials due to the similar propagation behaviours of electromagnetic waves in curved space and in inhomogeneous metamaterials. In a recent theoretical work by Narimanov and Kildishev, an optical black hole has been proposed based on metamaterials, in which the theoretical analysis and numerical simulations showed that all electromagnetic waves hitting it are trapped and absorbed. Here we report the first experimental demonstration of such an electromagnetic black hole in the microwave frequencies. The proposed black hole is composed of non-resonant and resonant metamaterial structures, which can trap and absorb electromagnetic waves coming from all directions spirally inwards without any reflections due to the local control of electromagnetic fields and the event horizon corresponding to the device boundary. It is shown that the absorption rate can reach 99% in the microwave frequencies. We expect that the electromagnetic black hole could be used as the thermal emitting source and to harvest the solar light.

  3. Black holes cannot support conformal scalar hair

    E-Print Network [OSTI]

    T. Zannias

    1994-09-14

    It is shown that the only static asymptotically flat non-extrema black hole solution of the Einstein-conformally invariant scalar field equations having the scalar field bounded on the horizon, is the Schwarzschild one. Thus black holes cannot be endowed with conformal scalar hair of finite length.

  4. Quantum Entropy of Charged Rotating Black Holes

    E-Print Network [OSTI]

    R. B. Mann

    1996-07-10

    I discuss a method for obtaining the one-loop quantum corrections to the tree-level entropy for a charged Kerr black hole. Divergences which appear can be removed by renormalization of couplings in the tree-level gravitational action in a manner similar to that for a static black hole.

  5. Topological Black Holes in Quantum Gravity

    E-Print Network [OSTI]

    J. Kowalski-Glikman; D. Nowak-Szczepaniak

    2000-07-31

    We derive the black hole solutions with horizons of non-trivial topology and investigate their properties in the framework of an approach to quantum gravity being an extension of Bohm's formulation of quantum mechanics. The solutions we found tend asymptotically (for large $r$) to topological black holes. We also analyze the thermodynamics of these space-times.

  6. Primordial black holes and asteroid danger

    E-Print Network [OSTI]

    Alexander Shatskiy

    2008-02-21

    Probability for a primordial black hole to invade the Kuiper belt was calculated. We showed that primordial black holes of certain masses can significantly change asteroids' orbits. These events may result in disasters, local for our solar system and global for the Earth (like the Tunguska meteorite). We also estimated how often such events occur.

  7. Stability of AdS black strings

    E-Print Network [OSTI]

    T. Delsate

    2008-08-14

    We review the recent developements in the stability problem and phase diagram for asymptotically locally $AdS$ black strings. First, we quickly review the case of locally flat black string before turning to the case of locally $AdS$ spacetimes.

  8. Canonical structure of 2D black holes

    E-Print Network [OSTI]

    Navarro-Salas, J; Talavera, C F

    1994-01-01

    We determine the canonical structure of two-dimensional black-hole solutions arising in $2D$ dilaton gravity. By choosing the Cauchy surface appropriately we find that the canonically conjugate variable to the black hole mass is given by the difference of local (Schwarzschild) time translations at right and left spatial infinities. This can be regarded as a generalization of Birkhoff's theorem.

  9. Fractal Statistics and Quantum Black Hole Entropy

    E-Print Network [OSTI]

    Wellington da Cruz

    2000-11-18

    Simple considerations about the fractal characteristic of the quantum-mechanical path give us the opportunity to derive the quantum black hole entropy in connection with the concept of fractal statistics. We show the geometrical origin of the numerical factor of four of the quantum black hole entropy expression and the statistics weight appears as a counting of the quanta of geometry.

  10. Can Superconducting Cosmic Strings Piercing Seed Black Holes Generate Supermassive Black Holes in the Early Universe?

    E-Print Network [OSTI]

    Lake, Matthew J

    2015-01-01

    The discovery of a large number of supermassive black holes at redshifts $z> 6$, when the Universe was only nine hundred million years old, has raised the fundamental question of how such massive compact objects could form in a (cosmologically) short time interval. Each of the proposed standard scenarios for black hole formation, involving rapid accretion of seed black holes, or black hole mergers, faces severe theoretical difficulties in explaining the short time formation of supermassive objects. In the present Letter, we propose an alternative scenario for the formation of supermassive black holes in the early Universe in which energy transfer from superconducting cosmic strings, piercing small seed black holes, is the main physical process leading to rapid mass increase. The increase in mass of a primordial seed black hole pierced by two antipodal strings is estimated and it is shown that this increases linearly in time. Due to the high energy transfer rate from the cosmic strings, we find that supermassi...

  11. Class Transitions in Black Holes

    E-Print Network [OSTI]

    Sandip K. Chakrabarti

    2005-01-14

    A black hole spectrum is known to change from the hard state to the soft state when the energy spectral index $\\alpha$ ($F_E \\propto E^{-\\alpha}$) in, say, 2-20 keV range changes from $\\alpha \\sim 0.5$ to $\\sim 1.5$. However, this `classical' definition which characterizes black holes like Cyg X-1, becomes less useful for many objects such as GRS 1915+105 in which the spectral slope is seen to vary from one to the other in a matter of seconds and depending on whether or not winds form, the spectral slope also changes. The light curves and the colour-colour diagrams may look completely different on different days depending on the frequency and mode of switching from one spectral state to the other. Though RXTE observations have yielded wealth of information on such `variability classes' in GRS 1915+105, very rarely one has been able to observe how the object goes from one class to the other. In the present review, we discuss possible origins of the class transition and present several examples of such transitions. In this context, we use mostly the results of the Indian X-ray Astronomy Experiment (IXAE) which observed GRS 1915+105 more regularly.

  12. Nonthermal correction to black hole spectroscopy

    E-Print Network [OSTI]

    Wen-Yu Wen

    2014-11-14

    Area spectrum of black holes have been obtained via various methods such as quasinormal modes, adiabatic invariance and angular momentum. Among those methods, calculations were done by assuming black holes in thermal equilibrium. Nevertheless, black holes in the asymptotically flat space usually have negative specific heat and therefore tend to stay away from thermal equilibrium. Even for those black holes with positive specific heat, temperature may still not be well defined in the process of radiation, due to the back reaction of decreasing mass. Respect to these facts, it is very likely that Hawking radiation is nonthermal and the area spectrum is no longer equidistant. In this note, we would like to illustrate how the area spectrum of black holes is corrected by this nonthermal effect.

  13. Fourier Analysis of the BTZ Black Hole

    E-Print Network [OSTI]

    Ian M. Tolfree

    2009-11-11

    In this paper we extend our previous work regarding the role of the Fourier transformation in bulk to boundary mappings to include the BTZ black hole. We follow standard procedures for modifying Fourier Transformations to accommodate quotient spaces and arrive at a bulk to boundary mapping in a black hole background. We show that this mapping is consistent with known results and lends a new insight into the AdS/CFT duality. We find that the micro-states corresponding to the entropy of a bulk scalar field are the Fourier coefficients on the boundary, which transform under the principal series representation of $SL(2,R)$. Building upon this we present a toy model to analyze the implications of this for the origin of black hole entropy. We find that the black hole micro-states live on the boundary and correspond to the possible emission modes of the black hole

  14. Evidence for the Black Hole Event Horizon

    E-Print Network [OSTI]

    Ramesh Narayan

    2003-10-23

    Astronomers have discovered many candidate black holes in X-ray binaries and in the nuclei of galaxies. The candidate objects are too massive to be neutron stars, and for this reason they are considered to be black holes. While the evidence based on mass is certainly strong, there is no proof yet that any of the objects possesses the defining characteristic of a black hole, namely an event horizon. Type I X-ray bursts, which are the result of thermonuclear explosions when gas accretes onto the surface of a compact star, may provide important evidence in this regard. Type I bursts are commonly observed in accreting neutron stars, which have surfaces, but have never been seen in accreting black hole candidates. It is argued that the lack of bursts in black hole candidates is compelling evidence that these objects do not have surfaces. The objects must therefore possess event horizons.

  15. How fast can a black hole rotate?

    E-Print Network [OSTI]

    Herdeiro, Carlos A R

    2015-01-01

    Kerr black holes have their angular momentum, $J$, bounded by their mass, $M$: $Jc\\leqslant GM^2$. There are, however, known black hole solutions violating this Kerr bound. We propose a very simple universal bound on the rotation, rather than on the angular momentum, of four-dimensional, stationary and axisymmetric, asymptotically flat black holes, given in terms of an appropriately defined horizon linear velocity, $v_H$. The $v_H$ bound is simply that $v_H$ cannot exceed the velocity of light. We verify the $v_H$ bound for known black hole solutions, including some that violate the Kerr bound, and conjecture that only extremal Kerr black holes saturate the $v_H$ bound.

  16. INCREASED OIL PRODUCTION AND RESERVES UTILIZING SECONDARY/TERTIARY RECOVERY TECHNIQUES ON SMALL RESERVOIRS IN THE PARADOX BASIN, UTAH

    SciTech Connect (OSTI)

    Thomas C. Chidsey, Jr.

    2002-11-01

    The Paradox Basin of Utah, Colorado, and Arizona contains nearly 100 small oil fields producing from shallow-shelf carbonate buildups or mounds within the Desert Creek zone of the Pennsylvanian (Desmoinesian) Paradox Formation. These fields typically have one to four wells with primary production ranging from 700,000 to 2,000,000 barrels (111,300-318,000 m{sup 3}) of oil per field at a 15 to 20 percent recovery rate. Five fields in southeastern Utah were evaluated for waterflood or carbon-dioxide (CO{sub 2})-miscible flood projects based upon geological characterization and reservoir modeling. Geological characterization on a local scale focused on reservoir heterogeneity, quality, and lateral continuity as well as possible compartmentalization within each of the five project fields. The Desert Creek zone includes three generalized facies belts: (1) open-marine, (2) shallow-shelf and shelf-margin, and (3) intra-shelf, salinity-restricted facies. These deposits have modern analogs near the coasts of the Bahamas, Florida, and Australia, respectively, and outcrop analogs along the San Juan River of southeastern Utah. The analogs display reservoir heterogeneity, flow barriers and baffles, and lithofacies geometry observed in the fields; thus, these properties were incorporated in the reservoir simulation models. Productive carbonate buildups consist of three types: (1) phylloid algal, (2) coralline algal, and (3) bryozoan. Phylloid-algal buildups have a mound-core interval and a supra-mound interval. Hydrocarbons are stratigraphically trapped in porous and permeable lithotypes within the mound-core intervals of the lower part of the buildups and the more heterogeneous supramound intervals. To adequately represent the observed spatial heterogeneities in reservoir properties, the phylloid-algal bafflestones of the mound-core interval and the dolomites of the overlying supra-mound interval were subdivided into ten architecturally distinct lithotypes, each of which exhibits a characteristic set of reservoir properties obtained from outcrop analogs, cores, and geophysical logs. The Anasazi and Runway fields were selected for geostatistical modeling and reservoir compositional simulations. Models and simulations incorporated variations in carbonate lithotypes, porosity, and permeability to accurately predict reservoir responses. History matches tied previous production and reservoir pressure histories so that future reservoir performances could be confidently predicted. The simulation studies showed that despite most of the production being from the mound-core intervals, there were no corresponding decreases in the oil in place in these intervals. This behavior indicates gravity drainage of oil from the supra-mound intervals into the lower mound-core intervals from which the producing wells' major share of production arises. The key to increasing ultimate recovery from these fields (and similar fields in the basin) is to design either waterflood or CO{sub 2}-miscible flood projects capable of forcing oil from high-storage-capacity but low-recovery supra-mound units into the high-recovery mound-core units. Simulation of Anasazi field shows that a CO{sub 2} flood is technically superior to a waterflood and economically feasible. For Anasazi field, an optimized CO{sub 2} flood is predicted to recover a total 4.21 million barrels (0.67 million m3) of oil representing in excess of 89 percent of the original oil in place. For Runway field, the best CO{sub 2} flood is predicted to recover a total of 2.4 million barrels (0.38 million m3) of oil representing 71 percent of the original oil in place. If the CO{sub 2} flood performed as predicted, it is a financially robust process for increasing the reserves in the many small fields in the Paradox Basin. The results can be applied to other fields in the Rocky Mountain region, the Michigan and Illinois Basins, and the Midcontinent.

  17. Increased oil production and reserves utilizing secondary/tertiary recovery techniques on small reservoirs in the Paradox basin, Utah. Annual report

    SciTech Connect (OSTI)

    Chidsey, T.C. Jr.

    1997-02-01

    The Paradox basin of Utah, Colorado, and Arizona contains nearly 100 small oil fields producing from carbonate buildups or mounds within the Pennsylvanian (Desmoinesian) Paradox Formation. These fields typically have one to four wells with primary production ranging from 700,000 to 2,000,000 barrels of oil per field at a 15 to 20% recovery rate. At least 200 million barrels of oil is at risk of being unrecovered in these small fields because of inefficient recovery practices and undrained heterogeneous reservoirs. Five fields (Anasazi, mule, Blue Hogan, heron North, and Runway) within the Navajo Nation of southeastern utah are being evaluated for waterflood or carbon-dioxide-miscible flood projects based upon geological characterization and reservoir modeling. The results can be applied to other fields in the Paradox basin and the Rocky Mountain region, the Michigan and Illinois basins, and the Midcontinent. The reservoir engineering component of the work completed to date included analysis of production data and well tests, comprehensive laboratory programs, and preliminary mechanistic reservoir simulation studies. A comprehensive fluid property characterization program was completed. Mechanistic reservoir production performance simulation studies were also completed.

  18. Morphology of PolyethyleneCarbon Black Composites G. BEAUCAGE,1

    E-Print Network [OSTI]

    Beaucage, Gregory

    -ray scattering (SAXS) study of a conductive grade of carbon black and carbon black­polymer composites and a power-law scaling of polydispersity. One use of conductive black­polyethylene composites is in circuit(methyl methacrylate); carbon black; filler; composite; conductivity; percolation INTRODUCTION The morphology

  19. Report on the WORKSHOP ON COMMERCIALIZATION OF BLACK LIQUOR

    E-Print Network [OSTI]

    .3. Gasifier Supplier Perspectives 11 Black Liquor Gasifier Suppliers 12 Biomass Gasifier Suppliers 13 5

  20. Testing black hole candidates with electromagnetic radiation

    E-Print Network [OSTI]

    Bambi, Cosimo

    2015-01-01

    Astrophysical black hole candidates are thought to be the Kerr black holes of general relativity, but there is currently no direct observational evidence that the spacetime geometry around these objects is described by the Kerr solution. The study of the properties of the electromagnetic radiation emitted by gas or stars orbiting these objects can potentially test the Kerr black hole hypothesis. In this paper, I review the state of the art of this research field, describing the possible approaches to test the Kerr metric with current and future observational facilities and discussing current constraints.

  1. Quasinormal Modes of Dirty Black Holes

    E-Print Network [OSTI]

    P. T. Leung; Y. T. Liu; W. -M. Suen; C. Y. Tam; K. Young

    1999-03-08

    Quasinormal mode (QNM) gravitational radiation from black holes is expected to be observed in a few years. A perturbative formula is derived for the shifts in both the real and the imaginary part of the QNM frequencies away from those of an idealized isolated black hole. The formulation provides a tool for understanding how the astrophysical environment surrounding a black hole, e.g., a massive accretion disk, affects the QNM spectrum of gravitational waves. We show, in a simple model, that the perturbed QNM spectrum can have interesting features.

  2. Black Hole Thermodynamics and Statistical Mechanics

    E-Print Network [OSTI]

    Steven Carlip

    2008-07-28

    We have known for more than thirty years that black holes behave as thermodynamic systems, radiating as black bodies with characteristic temperatures and entropies. This behavior is not only interesting in its own right; it could also, through a statistical mechanical description, cast light on some of the deep problems of quantizing gravity. In these lectures, I review what we currently know about black hole thermodynamics and statistical mechanics, suggest a rather speculative "universal" characterization of the underlying states, and describe some key open questions.

  3. Thermodynamics of Dyonic Lifshitz Black Holes

    E-Print Network [OSTI]

    Tobias Zingg

    2011-07-15

    Black holes with asymptotic anisotropic scaling are conjectured to be gravity duals of condensed matter system close to quantum critical points with non-trivial dynamical exponent z at finite temperature. A holographic renormalization procedure is presented that allows thermodynamic potentials to be defined for objects with both electric and magnetic charge in such a way that standard thermodynamic relations hold. Black holes in asymptotic Lifshitz spacetimes can exhibit paramagnetic behavior at low temperature limit for certain values of the critical exponent z, whereas the behavior of AdS black holes is always diamagnetic.

  4. Testing the Kerr black hole hypothesis

    E-Print Network [OSTI]

    Cosimo Bambi

    2011-10-13

    It is thought that the final product of the gravitational collapse is a Kerr black hole and astronomers have discovered several good astrophysical candidates. While there is some indirect evidence suggesting that the latter have an event horizon, and therefore that they are black holes, a proof that the space-time around these objects is described by the Kerr geometry is still lacking. Recently, there has been an increasing interest in the possibility of testing the Kerr black hole hypothesis with present and future experiments. In this paper, I briefly review the state of the art of the field, focussing on some recent results and work in progress.

  5. Scalar Perturbations of Charged Dilaton Black Holes

    E-Print Network [OSTI]

    Sharmanthie Fernando; Keith Arnold

    2015-08-01

    We have studied the scalar perturbation of static charged dilaton black holes in 3+1 dimensions. The black hole considered here is a solution to the low-energy string theory in 3+1 dimensions. The quasinormal modes for the scalar perturbations are calculated using the third order WKB method. The dilaton coupling constant has a considerable effect on the values of quasi normal modes. It is also observed that there is a linear relation between the quasi normal modes and the temperature for large black holes.

  6. Energy density bounds for black strings

    E-Print Network [OSTI]

    Shinya Tomizawa

    2005-06-07

    The conserved charge called Y-ADM mass density associated with asymptotically translational Killing-Yano tensor gives us an appropriate physical meaning about the energy density of $p$ brane spacetimes or black strings. We investigated the positivity of energy density in black string spacetimes, using the spinorial technique introduced by Witten. Recently, the positivity of Y-ADM mass density in p brane spacetimes was discussed. In this paper, we will extend this discussion to the transversely asymptotically flat black string spacetimes containing an apparent horizon. We will give the sufficient conditions for the Y-ADM mass density to become positive in such spacetimes.

  7. Thermodynamics and evaporation of the noncommutative black hole

    E-Print Network [OSTI]

    Yun Soo Myung; Yong-Wan Kim; Young-Jai Park

    2007-01-21

    We investigate the thermodynamics of the noncommutative black hole whose static picture is similar to that of the nonsingular black hole known as the de Sitter-Schwarzschild black hole. It turns out that the final remnant of extremal black hole is a thermodynamically stable object. We describe the evaporation process of this black hole by using the noncommutativity-corrected Vaidya metric. It is found that there exists a close relationship between thermodynamic approach and evaporation process.

  8. Energy of 4-Dimensional Black Hole, etc

    E-Print Network [OSTI]

    Dmitriy Palatnik

    2011-07-18

    In this letter I suggest possible redefinition of mass density, not depending on speed of the mass element, which leads to a more simple stress-energy for an object. I calculate energy of black hole.

  9. Horizon Operator Approach to Black Hole Quantization

    E-Print Network [OSTI]

    G. 't Hooft

    1994-02-21

    The $S$-matrix Ansatz for the construction of a quantum theory of black holes is further exploited. We first note that treating the metric tensor $g_{\\m\

  10. Topological Black Holes -- Outside Looking In

    E-Print Network [OSTI]

    R. B. Mann

    1997-09-15

    I describe the general mathematical construction and physical picture of topological black holes, which are black holes whose event horizons are surfaces of non-trivial topology. The construction is carried out in an arbitrary number of dimensions, and includes all known special cases which have appeared before in the literature. I describe the basic features of massive charged topological black holes in $(3+1)$ dimensions, from both an exterior and interior point of view. To investigate their interiors, it is necessary to understand the radiative falloff behaviour of a given massless field at late times in the background of a topological black hole. I describe the results of a numerical investigation of such behaviour for a conformally coupled scalar field. Significant differences emerge between spherical and higher genus topologies.

  11. Evidence for the Black Hole Event Horizon

    E-Print Network [OSTI]

    Ramesh Narayan; Jeremy S. Heyl

    2002-04-26

    Roughly a dozen X-ray binaries are presently known in which the compact accreting primary stars are too massive to be neutron stars. These primaries are identified as black holes, though there is as yet no definite proof that any of the candidate black holes actually possesses an event horizon. We discuss how Type I X-ray bursts may be used to verify the presence of the event horizon in these objects. Type I bursts are caused by thermonuclear explosions when gas accretes onto a compact star. The bursts are commonly seen in many neutron star X-ray binaries, but they have never been seen in any black hole X-ray binary. Our model calculations indicate that black hole candidates ought to burst frequently if they have surfaces. Based on this, we argue that the lack of bursts constitutes strong evidence for the presence of event horizons in these objects.

  12. CHARYBDIS: A Black hole event generator.

    E-Print Network [OSTI]

    Harris, Chris M.; Richardson, P.; Webber, Bryan R.

    CHARYBDIS is an event generator which simulates the production and decay of miniature black holes at hadronic colliders as might be possible in certain extra dimension models. It interfaces via the Les Houches accord to general purpose Monte...

  13. Spacetime constraints on accreting black holes

    SciTech Connect (OSTI)

    Garofalo, David [Jet Propulsion Laboratory, California Institute of Technology, Pasadena California 91109 (United States)

    2009-06-15

    We study the spin dependence of accretion onto rotating Kerr black holes using analytic techniques. In its linear regime, angular momentum transport in MHD turbulent accretion flow involves the generation of radial magnetic field connecting plasma in a differentially rotating flow. We take a first principles approach, highlighting the constraint that limits the generation and amplification of radial magnetic fields, stemming from the transfer of energy from mechanical to magnetic form. Because the energy transferred in magnetic form is ultimately constrained by gravitational potential energy or Killing energy, the spin dependence of the latter allows us to derive spin-dependent constraints on the success of the accreting plasma to expel its angular momentum. We find an inverse relationship between this ability and black hole spin. If this radial magnetic field generation forms the basis for angular momentum transfer in accretion flows, accretion rates involving Kerr black holes are expected to be lower as the black hole spin increases in the prograde sense.

  14. Black Hills Energy- Solar Power Program

    Broader source: Energy.gov [DOE]

    All incentive payments are subject to the availability of funds and a pre-installation site inspection. Black Hills Energy has established participation caps for each tier. The status of funding ...

  15. Classical and thermodynamic stability of black holes

    E-Print Network [OSTI]

    Monteiro, Ricardo

    2010-07-06

    Perturbations of the asymptotic charges . . . . . . . . . . . . . . . . 169 IV Conclusion 171 9 Conclusion and outlook 173 A Spectral numerical method 177 2 CONTENTS Part I Introduction 3 Chapter 1 Black holes Black holes are arguably the most interesting... to Newto- nian dynamics in the Solar system, and the indirect detection of gravitational waves from binary pulsars [1]. A crucial distinction from Newtonian gravity is that the “action-at-a-distance” is substituted by a built-in causality structure...

  16. Charged Cylindrical Black Holes in Conformal Gravity

    E-Print Network [OSTI]

    Jackson Levi Said; Joseph Sultana; Kristian Zarb Adami

    2013-01-04

    Considering cylindrical topology we present the static solution for a charged black hole in conformal gravity. We show that unlike the general relativistic case there are two different solutions, both including a factor that when set to zero recovers the familiar static charged black string solution in Einstein's theory. This factor gives rise to a linear term in the potential that also features in the neutral case and may have significant ramifications for particle trajectories.

  17. Black Holes and Biophysical (Mem)-branes

    E-Print Network [OSTI]

    Jay Armas; Troels Harmark

    2014-11-26

    We argue that the effective theory describing the long-wavelength dynamics of black branes is the same effective theory that describes the dynamics of biophysical membranes. We improve the phase structure of higher-dimensional black rings by considering finite thickness corrections in this effective theory, showing a striking agreement between our analytical results and recent numerical constructions while simultaneously drawing a parallel between gravity and the effective theory of biophysical membranes.

  18. Fractionated Branes and Black Hole Interiors

    E-Print Network [OSTI]

    Emil J. Martinec

    2015-05-20

    Combining a variety of results in string theory and general relativity, a picture of the black hole interior is developed wherein spacetime caps off at an inner horizon, and the inter-horizon region is occupied by a Hagedorn gas of a very low tension state of fractionated branes. This picture leads to natural resolutions of a variety of puzzles concerning quantum black holes. Gravity Research Foundation 2015 Fourth Prize Award for Essays on Gravitation.

  19. Nanoscopy Reveals Metallic Black Phosphorus

    E-Print Network [OSTI]

    Abate, Yohannes; Zhen, Li; Cronin, Stephen B; Wang, Han; Babicheva, Viktoriia; Javani, Mohammad H; Stockman, Mark I

    2015-01-01

    Layered and two-dimensional (2D) materials such as graphene, boron nitride, transition metal dichalcogenides(TMDCs), and black phosphorus (BP) have intriguing fundamental physical properties and bear promise of numerous important applications in electronics and optics. Of them, BP is a novel 2D material that has been theoretically predicted to acquire plasmonic behavior for frequencies below ~0.4 eV when highly doped. The electronic properties of BP are unique due to an anisotropic structure, which could strongly influence collective electronic excitations. Advantages of BP as a material for nanoelectronics and nanooptics are due to the fact that, in contrast to metals, the free carrier density in it can be dynamically controlled by electrostatic gating, which has been demonstrated by its use in field-effect transistors. Despite all the interest that BP attracts, near-field and plasmonic properties of BP have not yet been investigated experimentally. Here we report the first observation of nanoscopic near-fie...

  20. Rotating black hole thermodynamics with a particle probe

    SciTech Connect (OSTI)

    Gwak, Bogeun; Lee, Bum-Hoon

    2011-10-15

    The thermodynamics of Myers-Perry black holes in general dimensions are studied using a particle probe. When undergoing particle absorption, the changes of the entropy and irreducible mass are shown to be dependent on the particle radial momentum. The black hole thermodynamic behaviors are dependent on dimensionality for specific rotations. For a 4-dimensional Kerr black hole, its black hole properties are maintained for any particle absorption. 5-dimensional black holes can avoid a naked ring singularity by absorbing a particle in specific momenta ranges. Black holes over 6 dimensions become ultraspinning black holes through a specific form of particle absorption. The microscopical changes are interpreted in limited cases of Myers-Perry black holes using Kerr/CFT correspondence. We systematically describe the black hole properties changed by particle absorption in all dimensions.

  1. Lumpy AdS$\\bf{_5\\times}$ S$\\bf{^5}$ Black Holes and Black Belts

    E-Print Network [OSTI]

    Oscar J. C. Dias; Jorge E. Santos; Benson Way

    2015-01-26

    Sufficiently small Schwarzschild black holes in global AdS$_5\\times$S$^5$ are Gregory-Laflamme unstable. We construct new families of black hole solutions that bifurcate from the onset of this instability and break the full SO$(6)$ symmetry group of the S$^5$ down to SO$(5)$. These new "lumpy" solutions are labelled by the harmonics $\\ell$. We find evidence that the $\\ell = 1$ branch never dominates the microcanonical/canonical ensembles and connects through a topology-changing merger to a localised black hole solution with S$^8$ topology. We argue that these S$^8$ black holes should become the dominant phase in the microcanonical ensemble for small enough energies, and that the transition to Schwarzschild black holes is first order. Furthermore, we find two branches of solutions with $\\ell = 2$. We expect one of these branches to connect to a solution containing two localised black holes, while the other branch connects to a black hole solution with horizon topology $\\mathrm S^4\\times\\mathrm S^4$ which we call a "black belt".

  2. Classical and Quantum Reissner-Nordström Black Hole Thermodynamics and first order Phase Transition

    E-Print Network [OSTI]

    Hossein Ghaffarnejad

    2015-11-01

    First we consider CRNBH metric which is obtained by solving Einstein-Maxwell metric equation for a point electric charge $e$ inside of a spherical static body with mass $M$. It has 2 interior and exterior horizons. Using Bekenestein-Hawking entropy theorem we calculate interior and exterior entropy, temperature, Gibbs free energy and heat capacity at constant electric charge. We calculate first derivative of the Gibbs free energy with respect to temperature which become a singular function having a singularity at critical point with corresponding temperature $T_c=\\frac{1}{24\\pi \\sqrt{3}|e|}.$ Hence we clime first order phase transition is happened there. Temperature same as Gibbs free energy takes absolutely positive (negative) values on the exterior (interior) horizon. The Gibbs free energy takes two different positive values synchronously for $0black hole which its final remnant mass is $m_{final}=|e|$ in geometrical units. Its temperature and luminosity vanish but not in Schwarzschild case of evaporation. Our calculations can be takes some acceptable statements about information loss paradox .

  3. Holographic superconductor in the exact hairy black hole

    E-Print Network [OSTI]

    Yun Soo Myung; Chanyong Park

    2011-09-13

    We study the charged black hole of hyperbolic horizon with scalar hair (charged Martinez-Troncoso-Zanelli: CMTZ black hole) as a model of analytic hairy black hole for holographic superconductor. For this purpose, we investigate the second order phase transition between CMTZ and hyperbolic Reissner-Nordstr\\"om-AdS (HRNAdS) black holes. However, this transition unlikely occur. As an analytic treatment for holographic superconductor, we develop superconductor in the bulk and superfluidity on the boundary using the CMTZ black hole below the critical temperature. The presence of charge destroys the condensates around the zero temperature, which is in accord with the thermodynamic analysis of the CMTZ black hole.

  4. Electrically charged black hole with scalar hair

    E-Print Network [OSTI]

    Cristian Martinez; Ricardo Troncoso

    2006-06-16

    An electrically charged black hole solution with scalar hair in four dimensions is presented. The self-interacting scalar field is real and it is minimally coupled to gravity and electromagnetism. The event horizon is a surface of negative constant curvature and the asymptotic region is locally an AdS spacetime. The asymptotic fall-off of the fields is slower than the standard one. The scalar field is regular everywhere except at the origin, and is supported by the presence of electric charge which is bounded from above by the AdS radius. In turn, the presence of the real scalar field smooths the electromagnetic potential everywhere. Regardless the value of the electric charge, the black hole is massless and has a fixed temperature. The entropy follows the usual area law. It is shown that there is a nonvanishing probability for the decay of the hairy black hole into a charged black hole without scalar field. Furthermore, it is found that an extremal black hole without scalar field is likely to undergo a spontaneous dressing up with a nontrivial scalar field, provided the electric charge is below a critical value.

  5. The Environmental Impact of Supermassive Black Holes

    E-Print Network [OSTI]

    Abraham Loeb

    2004-08-10

    The supermassive black holes observed at the centers of almost all present-day galaxies, had a profound impact on their environment. I highlight the principle of self-regulation, by which supermassive black holes grow until they release sufficient energy to unbind the gas that feeds them from their host galaxy. This principle explains several observed facts, including the correlation between the mass of a central black hole and the depth of the gravitational potential well of its host galaxy, and the abundance and clustering properties of bright quasars in the redshift interval of z~2-6. At lower redshifts, quasars might have limited the maximum mass of galaxies through the suppression of cooling flows in X-ray clusters. The seeds of supermassive black holes were likely planted in dwarf galaxies at redshifts z>10, through the collapse of massive or supermassive stars. The minimum seed mass can be identified observationally through the detection of gravitational waves from black hole binaries by Advanced LIGO or LISA. Aside from shaping their host galaxies, quasar outflows filled the intergalactic medium with magnetic fields and heavy elements. Beyond the reach of these outflows, the brightest quasars at z>6 have ionized exceedingly large volumes of gas (tens of comoving Mpc) prior to global reionization, and must have suppressed the faint end of the galaxy luminosity function in these volumes before the same occurred through the rest of the universe.

  6. Perturbative String Thermodynamics near Black Hole Horizons

    E-Print Network [OSTI]

    Thomas G. Mertens; Henri Verschelde; Valentin I. Zakharov

    2015-07-01

    We provide further computations and ideas to the problem of near-Hagedorn string thermodynamics near (uncharged) black hole horizons, building upon our earlier work JHEP 1403 (2014) 086. The relevance of long strings to one-loop black hole thermodynamics is emphasized. We then provide an argument in favor of the absence of $\\alpha'$-corrections for the (quadratic) heterotic thermal scalar action in Rindler space. We also compute the large $k$ limit of the cigar orbifold partition functions (for both bosonic and type II superstrings) which allows a better comparison between the flat cones and the cigar cones. A discussion is made on the general McClain-Roth-O'Brien-Tan theorem and on the fact that different torus embeddings lead to different aspects of string thermodynamics. The black hole/string correspondence principle for the 2d black hole is discussed in terms of the thermal scalar. Finally, we present an argument to deal with arbitrary higher genus partition functions, suggesting the breakdown of string perturbation theory (in $g_s$) to compute thermodynamical quantities in black hole spacetimes.

  7. Thermodynamics and Luminosities of Rainbow Black Holes

    E-Print Network [OSTI]

    Benrong Mu; Peng Wang; Haitang Yang

    2015-07-14

    Doubly special relativity (DSR) is an effective model for encoding quantum gravity in flat spacetime. As a result of the nonlinearity of the Lorentz transformation, the energy-momentum dispersion relation is modified. One simple way to import DSR to curved spacetime is \\textquotedblleft Gravity's rainbow", where the spacetime background felt by a test particle would depend on its energy. Focusing on the \\textquotedblleft Amelino-Camelia dispersion relation" which is $E^{2}=m^{2}+p^{2}\\left[ 1-\\eta\\left( E/m_{p}\\right) ^{n}\\right] $ with $n>0$, we investigate the thermodynamical properties of a Schwarzschild black hole and a static uncharged black string for all possible values of $\\eta$ and $n$ in the framework of rainbow gravity. It shows that there are non-vanishing minimum masses for these two black holes in the cases with $\\eta<0$ and $n\\geq2$. Considering effects of rainbow gravity on both the Hawking temperature and radius of the event horizon, we use the geometric optics approximation to compute luminosities of a 2D black hole, a Schwarzschild one and a static uncharged black string. It is found that the luminosities can be significantly suppressed or boosted depending on the values of $\\eta$ and $n$.

  8. Black Hole Spin in AGN and GBHCs

    E-Print Network [OSTI]

    Christopher S. Reynolds; Laura W. Brenneman; David Garofalo

    2004-10-05

    We discuss constraints on black hole spin and spin-related astrophysics as derived from X-ray spectroscopy. After a brief discussion about the robustness with which X-ray spectroscopy can be used to probe strong gravity, we summarize how these techniques can constrain black hole spin. In particular, we highlight XMM-Newton studies of the Seyfert galaxy MCG-6-30-15 and the stellar-mass black hole GX339-4. The broad X-ray iron line profile, together with reasonable and general astrophysical assumptions, allow a non-rotating black hole to be rejected in both of these sources. If we make the stronger assertion of no emission from within the innermost stable circular orbit, the MCG-6-30-15 data constrain the dimensionless spin parameter to be a>0.93. Furthermore, these XMM-Newton data are already providing evidence for exotic spin-related astrophysics in the central regions of this object. We conclude with a discussion of the impact that Constellation-X will have on the study of strong gravity and black hole spin.

  9. Investigating Dark Energy with Black Hole Binaries

    E-Print Network [OSTI]

    Laura Mersini-Houghton; Adam Kelleher

    2009-06-08

    The accelerated expansion of the universe is ascribed to the existence of dark energy. Black holes accretion of dark energy induces a mass change proportional to the energy density and pressure of the background dark energy fluid. The time scale during which the mass of black holes changes considerably is too long relative to the age of the universe, thus beyond detection possibilities. We propose to take advantage of the modified black hole masses for exploring the equation of state $w[z]$ of dark energy, by investigating the evolution of supermassive black hole binaries on a dark energy background. Deriving the signatures of dark energy accretion on the evolution of binaries, we find that dark energy imprints on the emitted gravitational radiation and on the changes in the orbital radius of the binary can be within detection limits for certain supermassive black hole binaries. In this talk I describe how binaries can provide a useful tool in obtaining complementary information on the nature of dark energy, based on the work done with A.Kelleher.

  10. Rotating black lens solution in five dimensions

    SciTech Connect (OSTI)

    Chen Yu; Teo, Edward

    2008-09-15

    It has recently been shown that a stationary, asymptotically flat vacuum black hole in five space-time dimensions with two commuting axial symmetries must have an event horizon with either a spherical, ring or lens-space topology. In this paper, we study the third possibility, a so-called black lens with L(n,1) horizon topology. Using the inverse scattering method, we construct a black-lens solution with the simplest possible rod structure, and possessing a single asymptotic angular momentum. Its properties are then analyzed; in particular, it is shown that there must either be a conical singularity or a naked curvature singularity present in the space-time.

  11. Neutrino Majorana Mass from Black Hole

    E-Print Network [OSTI]

    Yosuke Uehara

    2002-05-25

    We propose a new mechanism to generate the neutrino Majorana mass in TeV-scale gravity models. The black hole violates all non-gauged symmetries and can become the origin of lepton number violating processes. The fluctuation of higher-dimensional spacetime can result in the production of a black hole, which emits 2 neutrinos. If neutrinos are Majorana particles, this process is equivalent to the free propagation of a neutrino with the insertion of the black hole. From this fact, we derive the neutrino Majorana mass. The result is completely consistent with the recently observed evidence of neutrinoless double beta decay. And the obtained neutrino Majorana mass satisfies the constraint from the density of the neutrino dark matter, which affects the cosmic structure formation. Furthermore, we can explain the ultrahigh energy cosmic rays by the Z-burst scenario with it.

  12. Numerical Analysis of Black Hole Evaporation

    E-Print Network [OSTI]

    Tsvi Piran; Andrew Strominger

    1993-04-28

    Black hole formation/evaporation in two-dimensional dilaton gravity can be described, in the limit where the number $N$ of matter fields becomes large, by a set of second-order partial differential equations. In this paper we solve these equations numerically. It is shown that, contrary to some previous suggestions, black holes evaporate completely a finite time after formation. A boundary condition is required to evolve the system beyond the naked singularity at the evaporation endpoint. It is argued that this may be naturally chosen so as to restore the system to the vacuum. The analysis also applies to the low-energy scattering of $S$-wave fermions by four-dimensional extremal, magnetic, dilatonic black holes.

  13. Black Hole Thermodynamics in Modified Gravity

    E-Print Network [OSTI]

    Jonas R. Mureika; John W. Moffat; Mir Faizal

    2015-03-03

    We analyze the thermodynamics of a non-rotating and rotating black hole in a modified theory of gravity that includes scalar and vector modifications to general relativity, which results in a modified gravitational constant $G = G_N(1+\\alpha)$ and a new gravitational charge $Q = \\sqrt{\\alpha G_N}M$. The influence of the parameter $\\alpha$ alters the non-rotating black hole's lifetime, temperature and entropy profiles from the standard Schwarzschild case. The thermodynamics of a rotating black hole is analyzed and it is shown to possess stable, cold remnants. The thermodynamic properties of a vacuum solution regular at $r=0$ are investigated and the solution without a horizon called a "gray hole" is not expected to possess an information loss problem.

  14. No Supermassive Black Hole in M33?

    E-Print Network [OSTI]

    David Merritt; Laura Ferrarese; Charles L. Joseph

    2001-07-20

    We analyze optical long-slit spectroscopy of the nucleus of M33 obtained from the Space Telescope Imaging Spectrograph aboard the Hubble Space Telescope. Rather than the steep rise expected within the radius of influence of a supermassive black hole, the velocity dispersion drops significantly within the inner parsec. Dynamical modelling yields an estimated upper limit of 3000 solar masses for the mass of a central compact object. This upper limit is however consistent within the uncertainties with the mass predicted by the M-sigma relation, which is between 2000 and 20,000 solar masses. We therefore can not conclude that the presence of a massive black hole in the nucleus of M33 would require a different formation mechanism from that of the black holes detected in galaxies with more luminous bulges.

  15. Dynamics of galaxy cores and supermassive black holes

    E-Print Network [OSTI]

    David Merritt

    2006-05-02

    Recent work on the dynamical evolution of galactic nuclei containing supermassive black holes is reviewed. Topics include galaxy structural properties; collisionless and collisional equilibria; loss-cone dynamics; and dynamics of binary and multiple supermassive black holes.

  16. Black hole Meissner effect and Blandford-Znajek jets

    E-Print Network [OSTI]

    Penna, Robert

    Spinning black holes tend to expel magnetic fields. In this way they are similar to superconductors. It has been a persistent concern that this black hole “Meissner effect” could quench jet power at high spins. This would ...

  17. CHARYBDIS: A Black Hole Event Generator

    E-Print Network [OSTI]

    C. M. Harris; P. Richardson; B. R. Webber

    2003-07-29

    CHARYBDIS is an event generator which simulates the production and decay of miniature black holes at hadronic colliders as might be possible in certain extra dimension models. It interfaces via the Les Houches accord to general purpose Monte Carlo programs like HERWIG and PYTHIA which then perform the parton evolution and hadronization. The event generator includes the extra-dimensional `grey-body' effects as well as the change in the temperature of the black hole as the decay progresses. Various options for modelling the Planck-scale terminal decay are provided.

  18. Virtual Black Holes in Hyperbolic Metamaterials

    E-Print Network [OSTI]

    Igor I. Smolyaninov

    2011-01-24

    Optical space in electromagnetic metamaterials may be engineered to emulate various exotic space-time geometries. However, these metamaterial models are limited in many respects. It is believed that real physical space-time strongly fluctuates on the Planck scale. These fluctuations are usually described as virtual black holes. Static metamaterial models introduced so far do not exhibit similar behavior. Here we demonstrate that thermal fluctuations of optical space in hyperbolic metamaterials lead to creation of virtual electromagnetic black holes. This effect is very large if the dielectric component of the metamaterial exhibits critical opalescence.

  19. Vacuum polarization for lukewarm black holes

    E-Print Network [OSTI]

    Elizabeth Winstanley; Phil M. Young

    2007-12-20

    We compute the renormalized expectation value of the square of a quantum scalar field on a Reissner-Nordstrom-de Sitter black hole in which the temperatures of the event and cosmological horizons are equal (`lukewarm' black hole). Our numerical calculations for a thermal state at the same temperature as the two horizons indicate that this renormalized expectation value is regular on both the event and cosmological horizons. We are able to show analytically, using an approximation for the field modes near the horizons, that this is indeed the case.

  20. Thermal Gravitational Waves from Primordial Black Holes

    E-Print Network [OSTI]

    C. Sivaram; Kenath Arun

    2010-05-19

    Thermal gravitational waves can be generated in various sources such as, in the cores of stars, white dwarfs and neutron stars due to the fermion collisions in the dense degenerate Fermi gas. Such high frequency thermal gravitational waves can also be produced during the collisions in a gamma ray burst or during the final stages of the evaporation of primordial black holes. Here we estimate the thermal gravitational waves from primordial black holes and estimate the integrated energy of the gravitational wave emission over the entire volume of the universe and over Hubble time. We also estimate the gravitational wave flux from gamma ray bursts and jets.

  1. Thermal stability of radiant black holes

    E-Print Network [OSTI]

    Parthasarathi Majumdar

    2006-04-06

    Beginning with a brief sketch of the derivation of Hawking's theorem of horizon area increase, based on the Raychaudhuri equation, we go on to discuss the issue as to whether generic black holes, undergoing Hawking radiation, can ever remain in stable thermal equilibrium with that radiation. We derive a universal criterion for such a stability, which relates the black hole mass and microcanonical entropy, both of which are well-defined within the context of the Isolated Horizon, and in principle calculable within Loop Quantum Gravity. The criterion is argued to hold even when thermal fluctuations of electric charge are considered, within a {\\it grand} canonical ensemble.

  2. Magnetized black hole as a gravitational lens

    E-Print Network [OSTI]

    R. A. Konoplya

    2006-11-19

    We use the Ernst-Schwarzschild solution for a black hole immersed in a uniform magnetic field to estimate corrections to the bending angle and time delay due-to presence of weak magnetic fields in galaxies and between galaxies, and also due-to influence of strong magnetic field near supermassive black holes. The magnetic field creates a kind of confinement in space, that leads to increasing of the bending angle and time delay for a ray of light propagating in the equatorial plane.

  3. Entropy and Area of Black Holes in Loop Quantum Gravity

    E-Print Network [OSTI]

    I. B. Khriplovich

    2002-03-31

    Simple arguments related to the entropy of black holes strongly constrain the spectrum of the area operator for a Schwarzschild black hole in loop quantum gravity. In particular, this spectrum is fixed completely by the assumption that the black hole entropy is maximum. Within the approach discussed, one arrives in loop quantum gravity at a quantization rule with integer quantum numbers $n$ for the entropy and area of a black hole.

  4. UofT Wireless Network BlackBerry 6 Setup

    E-Print Network [OSTI]

    UofT Wireless Network BlackBerry 6 Setup Note:theseinstructionsweretestedonaBlackBerryBold9700,OS6-4357,help.desk@utoronto.ca). UofT Wireless Network BlackBerry 10 Setup Note: these instructions were tested on a BlackBerry Q10. 1. Before you can use the UofT wireless network, you must verify your UTORid (you

  5. SEARCH FOR SUPERMASSIVE BLACK HOLE BINARIES IN THE SLOAN DIGITAL...

    Office of Scientific and Technical Information (OSTI)

    ASTROPHYSICS; BLACK HOLES; COMPARATIVE EVALUATIONS; CORRELATIONS; COSMOLOGY; GALAXIES; GALAXY NUCLEI; NONLUMINOUS MATTER; OSCILLATIONS; QUASARS; VELOCITY Word Cloud More Like This...

  6. Location and Geology Fig 1. The Macasty black shale

    E-Print Network [OSTI]

    to the chondritic uniform reservoir (CHUR; black line) and the depleted mantle (purple line). The parameters of CHUR by calcite. Fig. 5. Pyritized fracture Fig. 6. Massive black shale Fig. 7. Graptolite in black shale Fig. 8 shale, - Measure the concentrations of major, minor and trace elements including organic carbon

  7. Emission of scalar particles from cylindrical black holes

    E-Print Network [OSTI]

    H. Gohar; K. Saifullah

    2011-09-27

    We study quantum tunneling of scalar particles from black strings. For this purpose we apply WKB approximation and Hamilton-Jacobi method to solve the Klein-Gordon equation for outgoing trajectories. We find the tunneling probability of outgoing charged and uncharged scalars from the event horizon of black strings, and hence the Hawking temperature for these black configurations.

  8. The Role of Primordial Kicks on Black Hole Merger Rates

    E-Print Network [OSTI]

    Miroslav Micic; Tom Abel; Steinn Sigurdsson

    2006-09-06

    Primordial stars are likely to be very massive $\\geq30\\Msun$, form in isolation, and will likely leave black holes as remnants in the centers of their host dark matter halos in the mass range $10^{6}-10^{10}\\Ms$. Such early black holes, at redshifts z$\\gtsim10$, could be the seed black holes for the many supermassive black holes found in galaxies in the local universe. If they exist, their mergers with nearby supermassive black holes may be a prime signal for long wavelength gravitational wave detectors. We simulate formation of black holes in the center of high redshift dark matter halos and explore implications of initial natal kick velocities conjectured by some formation models. The central concentration of early black holes in present day galaxies is reduced if they are born even with moderate kicks of tens of km/s. The modest kicks allow the black holes to leave their parent halo, which consequently leads to dynamical friction being less effective on the lower mass black holes as compared to those still embedded in their parent halos. Therefore, merger rates may be reduced by more than an order of magnitude. Using analytical and illustrative cosmological N--body simulations we quantify the role of natal kicks of black holes formed from massive metal free stars on their merger rates with supermassive black holes in present day galaxies. Our results also apply to black holes ejected by the gravitational slingshot mechanism.

  9. Charged fermions tunneling from accelerating and rotating black holes

    SciTech Connect (OSTI)

    Rehman, Mudassar; Saifullah, K., E-mail: mudassir051@yahoo.com, E-mail: saifullah@qau.edu.pk [Department of Mathematics, Quaid-i-Azam University, Islamabad (Pakistan)

    2011-03-01

    We study Hawking radiation of charged fermions from accelerating and rotating black holes with electric and magnetic charges. We calculate the tunneling probabilities of incoming and outgoing fermionic particles and find the Hawking temperature of these black holes. We also provide an explicit expression of the classical action for the massive and massless particles in the background of these black holes.

  10. Detroit to Durban: Black Workers' Common Struggle; Southern Africa/Black America: Same Struggles, Same Fight

    E-Print Network [OSTI]

    Philips, John

    1978-01-01

    DETROIT TO DURBAN: BlACK \\\\OOKERS CCM1>N STRUGGLE by Blackearliest parrphlet is Detroit to Durban . Although publishedstrikes of early 1973 and the Detroit riots of 1967 is a bit

  11. Brief review on higher spin black holes

    E-Print Network [OSTI]

    Alfredo Perez; David Tempo; Ricardo Troncoso

    2014-05-12

    We review some relevant results in the context of higher spin black holes in three-dimensional spacetimes, focusing on their asymptotic behaviour and thermodynamic properties. For simplicity, we mainly discuss the case of gravity nonminimally coupled to spin-3 fields, being nonperturbatively described by a Chern-Simons theory of two independent sl(3,R) gauge fields. Since the analysis is particularly transparent in the Hamiltonian formalism, we provide a concise discussion of their basic aspects in this context; and as a warming up exercise, we briefly analyze the asymptotic behaviour of pure gravity, as well as the BTZ black hole and its thermodynamics, exclusively in terms of gauge fields. The discussion is then extended to the case of black holes endowed with higher spin fields, briefly signaling the agreements and discrepancies found through different approaches. We conclude explaining how the puzzles become resolved once the fall off of the fields is precisely specified and extended to include chemical potentials, in a way that it is compatible with the asymptotic symmetries. Hence, the global charges become completely identified in an unambiguous way, so that different sets of asymptotic conditions turn out to contain inequivalent classes of black hole solutions being characterized by a different set of global charges.

  12. Quantum Chaos and the Black Body Radiation

    E-Print Network [OSTI]

    Giulio Casati

    2000-11-16

    We discuss a mechanical model which mimics the main features of the radiation matter interaction in the black body problem. The pure classical dynamical evolution, with a simple discretization of the action variables, leads to the Stefan- Boltzmann law and to the Planck distribution without any additional statistical assumption.

  13. Scalar Hairy Black Holes in General Dimensions

    E-Print Network [OSTI]

    Xing-Hui Feng; H. Lu; Qiang Wen

    2014-01-13

    We obtain a class of asymptotic flat or (A)dS hairy black holes in D-dimensional Einstein gravity coupled to a scalar with certain scalar potential. For a given mass, the theory admits both the Schwarzschild-Tangherlini and the hairy black holes with different temperature and entropy, but satisfying the same first law of thermodynamics. For some appropriate choice of parameters, the scalar potential can be expressed in terms of a super-potential and it can arise in gauged supergravities. In this case, the solutions develop a naked curvature singularity and become the spherical domain walls. Uplifting the solutions to D=11 or 10, we obtain solutions that can be viewed as spherical M-branes or D3-branes. We also add electric charges to these hairy black holes. All these solutions contain no scalar charges in that the first law of thermodynamics are unmodified. We also try to construct new AdS black holes carrying scalar charges, with some moderate success in that the charges are pre-fixed in the theory instead of being some continuous integration constants.

  14. Scalar Hairy Black Holes in General Dimensions

    E-Print Network [OSTI]

    Feng, Xing-Hui; Wen, Qiang

    2013-01-01

    We obtain a class of asymptotic flat or (A)dS hairy black holes in D-dimensional Einstein gravity coupled to a scalar with certain scalar potential. For a given mass, the theory admits both the Schwarzschild-Tangherlini and the hairy black holes with different temperature and entropy, but satisfying the same first law of thermodynamics. For some appropriate choice of parameters, the scalar potential can be expressed in terms of a super-potential and it can arise in gauged supergravities. In this case, the solutions develop a naked curvature singularity and become the spherical domain walls. Uplifting the solutions to D=11 or 10, we obtain solutions that can be viewed as spherical M-branes or D3-branes. We also add electric charges to these hairy black holes. All these solutions contain no scalar charges in that the first law of thermodynamics are unmodified. We also try to construct new AdS black holes carrying scalar charges, with some moderate success in that the charges are pre-fixed in the theory instead ...

  15. Bubbling supertubes and foaming black holes

    SciTech Connect (OSTI)

    Bena, Iosif; Warner, Nicholas P.

    2006-09-15

    We construct smooth BPS three-charge geometries that resolve the zero-entropy singularity of the U(1)xU(1) invariant black ring. This singularity is resolved by a geometric transition that results in geometries without any branes sources or singularities but with nontrivial topology. These geometries are both ground states of the black ring, and nontrivial microstates of the D1-D5-P system. We also find the form of the geometries that result from the geometric transition of N zero-entropy black rings, and argue that, in general, such geometries give a very large number of smooth bound-state three-charge solutions, parametrized by 6N functions. The generic microstate solution is specified by a four-dimensional hyper-Kaehler geometry of a certain signature, and contains a 'foam' of nontrivial two-spheres. We conjecture that these geometries will account for a significant part of the entropy of the D1-D5-P black hole, and that Mathur's conjecture might reduce to counting certain hyper-Kaehler manifolds.

  16. Schwarzschild black hole in dark energy background

    E-Print Network [OSTI]

    Ngangbam Ishwarchandra; Ng. Ibohal; K. Yugindro Singh

    2014-09-27

    In this paper we present an exact solution of Einstein's field equations describing the Schwarzschild black hole in dark energy background. It is also regarded as an embedded solution that the Schwarzschild black hole is embedded into the dark energy space producing Schwarzschild-dark energy black hole. It is found that the space-time geometry of Schwarzschild-dark energy solution is non-vacuum Petrov type $D$ in the classification of space-times. We study the energy conditions (like weak, strong and dominant conditions) for the energy-momentum tensor of the Schwarzschild-dark energy solution. We also find that the energy-momentum tensor of the Schwarzschild-dark energy solution violates the strong energy condition due to the negative pressure leading to a repulsive gravitational force of the matter field in the space-time. It is shown that the time-like vector field for an observer in the Schwarzschild-dark energy space is expanding, accelerating, shearing and non-rotating. We investigate the surface gravity and the area of the horizons for the Schwarzschild-dark energy black hole.

  17. Pulsed combustion process for black liquor gasification

    SciTech Connect (OSTI)

    Durai-Swamy, K.; Mansour, M.N.; Warren, D.W.

    1991-02-01

    The objective of this project is to test an energy efficient, innovative black liquor recovery system on an industrial scale. In the MTCI recovery process, black liquor is sprayed directly onto a bed of sodium carbonate solids which is fluidized by steam. Direct contact of the black liquor with hot bed solids promotes high rates of heating and pyrolysis. Residual carbon, which forms as a deposit on the particle surface, is then gasified by reaction with steam. Heat is supplied from pulse combustor resonance tubes which are immersed within the fluid bed. A portion of the gasifier product gas is returned to the pulse combustors to provide the energy requirements of the reactor. Oxidized sulfur species are partially reduced by reaction with the gasifier products, principally carbon monoxide and hydrogen. The reduced sulfur decomposed to solid sodium carbonate and gaseous hydrogen sulfide (H{sub 2}S). Sodium values are recovered by discharging a dry sodium carbonate product from the gasifier. MTCI's indirectly heated gasification technology for black liquor recovery also relies on the scrubbing of H{sub 2}S for product gases to regenerate green liquor for reuse in the mill circuit. Due to concerns relative to the efficiency of sulfur recovery in the MTCI integrated process, an experimental investigation was undertaken to establish performance and design data for this portion of the system.

  18. Six Sigma Black Belts Fight For Quality

    E-Print Network [OSTI]

    Vardeman, Stephen B.

    Six Sigma Black Belts Fight For Quality Ron Scott Ross Finnestad Rodney Kalsow IE 361 mini-paper 9/22/00 #12;Six Sigma is a breakthrough management strategy that is revolutionizing the world's top corporations. So what is Six Sigma? "It is a business process that allows companies to drastically improve

  19. Lower-Dimensional Black Hole Chemistry

    E-Print Network [OSTI]

    Antonia M. Frassino; Robert B. Mann; Jonas R. Mureika

    2015-09-18

    The connection between black hole thermodynamics and chemistry is extended to the lower-dimensional regime by considering the rotating and charged BTZ metric in the $(2+1)$-D and a $(1+1)$-D limits of Einstein gravity. The Smarr relation is naturally upheld in both BTZ cases, where those with $Q \

  20. Strains and Jets in Black Hole Fields

    E-Print Network [OSTI]

    D. Bini; F. de Felice; A. Geralico

    2007-12-14

    We study the behaviour of an initially spherical bunch of particles emitted along trajectories parallel to the symmetry axis of a Kerr black hole. We show that, under suitable conditions, curvature and inertial strains compete to generate jet-like structures.

  1. Area products for black hole horizons

    E-Print Network [OSTI]

    Visser, Matt

    2013-01-01

    Area products for multi-horizon black holes often have intriguing properties, and are often independent of the mass of the black hole (depending only on various charges, angular momenta, and moduli). Such products are often formulated in terms of the areas of inner (Cauchy) horizons and event horizons, and often include the effects of unphysical "virtual'" horizons. For the Schwarzschild-de Sitter [Kottler] black hole in (3+1) dimensions it is shown by explicit exact calculation that the product of event horizon area and cosmological horizon area is not mass independent. (Including the effect of the third "virtual" horizon does not improve the situation.) Similarly, in the Reissner-Nordstrom-anti-de Sitter black hole in (3+1) dimensions the product of inner (Cauchy) horizon area and event horizon area is calculated (perturbatively), and is shown to be not mass independent. That is, the mass-independence of the product of physical horizon areas is not generic. In the generic situation, whenever the quasi-local...

  2. Report Review Checklist a. Ink is Black

    E-Print Network [OSTI]

    Report Review Checklist 1. General a. Ink is Black b. Margins Left & Top 1.5"; Right & Bottom 1" c. Page Numbers 1. Arabic numerals upper right corner within body of paper 2. Page Numbers: Lower case roman numerals for front matter. d. Spacing: Double spaced throughout report. e. Typeface: Arial, Times

  3. Black Cowboys and Black Masculinity African American Ranchers, Rodeo Cowboys and Trailriders 

    E-Print Network [OSTI]

    Babers, Myeshia Chanel

    2014-12-17

    in the works of W. E. B. DuBois, Booker T. Washington, and Cater G. Woodson. Although disciplinary approaches, individual motivations, and prescriptions for the perceived “Negro Problem” in America vary, one common issue that scholars reproach is the idea... information about Black cowboys creates a peculiar position regarding notions, representations, and understandings about the racially signified cowboys. One common issue regarding Black identity that scholars reproach is the idea that it is pathological...

  4. Trumpet-puncture initial data for black holes

    SciTech Connect (OSTI)

    Immerman, Jason D.; Baumgarte, Thomas W.

    2009-09-15

    We propose a new approach, based on the puncture method, to construct black hole initial data in the so-called trumpet geometry, i.e. on slices that asymptote to a limiting surface of nonzero areal radius. Our approach is easy to implement numerically and, at least for nonspinning black holes, does not require any internal boundary conditions. We present numerical results, obtained with a uniform-grid finite-difference code, for boosted black holes and binary black holes. We also comment on generalizations of this method for spinning black holes.

  5. Acoustic clouds: standing sound waves around a black hole analogue

    E-Print Network [OSTI]

    Carolina L. Benone; Luis C. B. Crispino; Carlos Herdeiro; Eugen Radu

    2015-01-28

    Under certain conditions sound waves in fluids experience an acoustic horizon with analogue properties to those of a black hole event horizon. In particular, a draining bathtub-like model can give rise to a rotating acoustic horizon and hence a rotating black hole (acoustic) analogue. We show that sound waves, when enclosed in a cylindrical cavity, can form stationary waves around such rotating acoustic black holes. These acoustic perturbations display similar properties to the scalar clouds that have been studied around Kerr and Kerr-Newman black holes; thus they are dubbed acoustic clouds. We make the comparison between scalar clouds around Kerr black holes and acoustic clouds around the draining bathtub explicit by studying also the properties of scalar clouds around Kerr black holes enclosed in a cavity. Acoustic clouds suggest the possibility of testing, experimentally, the existence and properties of black hole clouds, using analog models.

  6. Thermodynamic Relations for Kiselev and Dilaton Black Hole

    E-Print Network [OSTI]

    Bushra Majeed; Mubasher Jamil; Parthapratim Pradhan

    2015-08-24

    We investigate the thermodynamics and phase transition for Kiselev black hole and dilaton black hole. Speci?cally we consider Reissner Nordstrom black hole surrounded by radiation and dust, and Schwarzschild black hole surrounded by quintessence, as special cases of Kiselev solution. We have calculated the products relating the surface gravities, surface temperatures, Komar energies, areas, entropies, horizon radii and the irreducible masses at the Cauchy and the event horizons. It is observed that the product of surface gravities, surface temperature product and product of Komar energies at the horizons are not universal quantities for the Kiselev solutions while products of areas and entropies at both the horizons are independent of mass of the above mentioned black holes (except for Schwarzschild black hole surrounded by quintessence). For charged dilaton black hole, all the products vanish. First law of thermodynamics is also veri?ed for Kiselev solutions. Heat capacities are calculated and phase transitions are observed, under certain conditions.

  7. Quantization of black holes by analogy with hydrogen atoms

    E-Print Network [OSTI]

    Chang Liu; Yan-Gang Miao; Yu-Mei Wu; Yu-Hao Zhang

    2015-11-16

    We suggest a proposal of quantization for black holes that is based on an analogy between a black hole and a hydrogen atom. A self-regular Schwarzschild-AdS black hole is investigated, where the mass density of the extreme black hole is given by the probability density of the ground state of hydrogen atoms and the mass densities of non-extreme black holes are chosen to be the probability densities of excited states with no angular momenta. Consequently, it is logical to accept quantization of mean radii of hydrogen atoms as that of black hole horizons. In this way, quantization of total black hole masses is deduced. Furthermore, the quantum hoop conjecture and the Correspondence Principle are discussed.

  8. Quantization of black holes by analogy with hydrogen atoms

    E-Print Network [OSTI]

    Liu, Chang; Wu, Yu-Mei; Zhang, Yu-Hao

    2015-01-01

    We suggest a proposal of quantization for black holes that is based on an analogy between a black hole and a hydrogen atom. A self-regular Schwarzschild-AdS black hole is investigated, where the mass density of the extreme black hole is given by the probability density of the ground state of hydrogen atoms and the mass densities of non-extreme black holes are chosen to be the probability densities of excited states with no angular momenta. Consequently, it is logical to accept quantization of mean radii of hydrogen atoms as that of black hole horizons. In this way, quantization of total black hole masses is deduced. Furthermore, the quantum hoop conjecture and the Correspondence Principle are discussed.

  9. Quantization of black holes by analogy with hydrogen atoms

    E-Print Network [OSTI]

    Chang Liu; Yan-Gang Miao; Yu-Mei Wu; Yu-Hao Zhang

    2015-11-23

    We suggest a proposal of quantization for black holes that is based on an analogy between a black hole and a hydrogen atom. A self-regular Schwarzschild-AdS black hole is investigated, where the mass density of the extreme black hole is given by the probability density of the ground state of hydrogen atoms and the mass densities of non-extreme black holes are chosen to be the probability densities of excited states with no angular momenta. Consequently, it is logical to accept quantization of mean radii of hydrogen atoms as that of black hole horizons. In this way, quantization of total black hole masses is deduced. Furthermore, the quantum hoop conjecture and the Correspondence Principle are discussed.

  10. Energy Extraction from Spinning Black Holes via Relativistic Jets

    E-Print Network [OSTI]

    Ramesh Narayan; Jeffrey E. McClintock; Alexander Tchekhovskoy

    2013-03-12

    It has for long been an article of faith among astrophysicists that black hole spin energy is responsible for powering the relativistic jets seen in accreting black holes. Two recent advances have strengthened the case. First, numerical general relativistic magnetohydrodynamic simulations of accreting spinning black holes show that relativistic jets form spontaneously. In at least some cases, there is unambiguous evidence that much of the jet energy comes from the black hole, not the disk. Second, spin parameters of a number of accreting stellar-mass black holes have been measured. For ballistic jets from these systems, it is found that the radio luminosity of the jet correlates with the spin of the black hole. This suggests a causal relationship between black hole spin and jet power, presumably due to a generalized Penrose process.

  11. The Role of Primordial Kicks on Black Hole Merger Rates

    E-Print Network [OSTI]

    Miroslav Micic; Tom Abel; Steinn Sigurdsson

    2006-09-15

    Primordial stars are likely to be very massive >30 Msun, form in isolation, and will likely leave black holes as remnants in the centers of their host dark matter halos. We expect primordial stars to form in halos in the mass range 10^6-10^10 Msun. Some of these early black holes, formed at redshifts z>10, could be the seed black hole for a significant fraction of the supermassive black holes found in galaxies in the local universe. If the black hole descendants of the primordial stars exist, their mergers with nearby supermassive black holes may be a prime candidate for long wavelength gravitational wave detectors. We simulate formation and evolution of dark matter halos in LambdaCDM universe. We seed high-redshift dark matter halos with early black holes, and explore the merger history of the host halos and the implications of black hole's kick velocities arising from their coalescence. The central concentration of low mass early black holes in present day galaxies is reduced if they experience even moderate kicks of tens of km/s. Even such modest kicks allow the black holes to leave their parent halo, which consequently leads to dynamical friction being less effective on the low mass black holes that were ejected, compared to those still embedded in their parent halos. Therefore, merger rates with central supermassive black holes in the largest halos may be reduced by more than an order of magnitude. Using analytical and illustrative cosmological N-body simulations, we quantify the role of kicks on the merger rates of black holes formed from massive metal free stars with supermassive black holes in present day galaxies.

  12. Hovering Black Holes from Charged Defects

    E-Print Network [OSTI]

    Gary T. Horowitz; Nabil Iqbal; Jorge E. Santos; Benson Way

    2015-05-05

    We construct the holographic dual of an electrically charged, localised defect in a conformal field theory at strong coupling, by applying a spatially dependent chemical potential. We find that the IR behaviour of the spacetime depends on the spatial falloff of the potential. Moreover, for sufficiently localized defects with large amplitude, we find that a new gravitational phenomenon occurs: a spherical extremal charged black hole nucleates in the bulk: a hovering black hole. This is a second order quantum phase transition. We construct this new phase with several profiles for the chemical potential and study its properties. We find an apparently universal behaviour for the entropy of the defect as a function of its amplitude. We comment on the possible field theory implications of our results.

  13. Astrophysical black holes in screened modified gravity

    SciTech Connect (OSTI)

    Davis, Anne-Christine; Jha, Rahul; Muir, Jessica; Gregory, Ruth E-mail: r.a.w.gregory@durham.ac.uk E-mail: jlmuir@umich.edu

    2014-08-01

    Chameleon, environmentally dependent dilaton, and symmetron gravity are three models of modified gravity in which the effects of the additional scalar degree of freedom are screened in dense environments. They have been extensively studied in laboratory, cosmological, and astrophysical contexts. In this paper, we present a preliminary investigation into whether additional constraints can be provided by studying these scalar fields around black holes. By looking at the properties of a static, spherically symmetric black hole, we find that the presence of a non-uniform matter distribution induces a non-constant scalar profile in chameleon and dilaton, but not necessarily symmetron gravity. An order of magnitude estimate shows that the effects of these profiles on in-falling test particles will be sub-leading compared to gravitational waves and hence observationally challenging to detect.

  14. Black Hole Portal into Hidden Valleys

    E-Print Network [OSTI]

    Sergei Dubovsky; Victor Gorbenko

    2010-12-13

    Superradiant instability turns rotating astrophysical black holes into unique probes of light axions. We consider what happens when a light axion is coupled to a strongly coupled hidden gauge sector. In this case superradiance results in an adiabatic increase of a hidden sector CP-violating $\\theta$-parameter in a near horizon region. This may trigger a first order phase transition in the gauge sector. As a result a significant fraction of a black hole mass is released as a cloud of hidden mesons and can be later converted into electromagnetic radiation. This results in a violent electromagnetic burst. The characteristic frequency of such bursts may range approximately from 100 eV to 100 MeV.

  15. Puncture Evolution of Schwarzschild Black Holes

    E-Print Network [OSTI]

    J. David Brown

    2008-01-15

    The moving puncture method is analyzed for a single, non-spinning black hole. It is shown that the puncture region is not resolved by current numerical codes. As a result, the geometry near the puncture appears to evolve to an infinitely long cylinder of finite areal radius. The puncture itself actually remains at spacelike infinity throughout the evolution. In the limit of infinite resolution the data never become stationary. However, at any reasonable finite resolution the grid points closest to the puncture are rapidly drawn into the black hole interior by the Gamma-driver shift condition. The data can then evolve to a stationary state. These results suggest that the moving puncture technique should be viewed as a type of "natural excision".

  16. Hybrid black-hole binary initial data

    E-Print Network [OSTI]

    Bruno C. Mundim; Bernard J. Kelly; Yosef Zlochower; Hiroyuki Nakano; Manuela Campanelli

    2010-12-04

    Traditional black-hole binary puncture initial data is conformally flat. This unphysical assumption is coupled with a lack of radiation signature from the binary's past life. As a result, waveforms extracted from evolutions of this data display an abrupt jump. In Kelly et al. [Class.Quant.Grav.27:114005,2010], a new binary black-hole initial data with radiation contents derived in the post-Newtonian (PN) calculation was adapted to puncture evolutions in numerical relativity. This data satisfies the constraint equations to the 2.5PN order, and contains a transverse-traceless "wavy" metric contribution, violating the standard assumption of conformal flatness. Although the evolution contained less spurious radiation, there were undesired features; the unphysical horizon mass loss and the large initial orbital eccentricity. Introducing a hybrid approach to the initial data evaluation, we significantly reduce these undesired features.

  17. Electromagnetic Jets from Stars and Black Holes

    E-Print Network [OSTI]

    Samuel E. Gralla; Alexandru Lupsasca; Maria J. Rodriguez

    2015-04-08

    We present analytic force-free solutions modeling rotating stars and black holes immersed in the magnetic field of a thin disk that terminates at an inner radius. The solutions are exact in flat spacetime and approximate in Kerr spacetime. The compact object produces a conical jet whose properties carry information about its nature. For example, the jet from a star is surrounded by a current sheet, while that of a black hole is smooth. We compute an effective resistance in each case and compare to the canonical values used in circuit models of energy extraction. These solutions illustrate all of the basic features of the Blandford-Znajek process for energy extraction and jet formation in a clean setting.

  18. Electromagnetic Jets from Stars and Black Holes

    E-Print Network [OSTI]

    Gralla, Samuel E; Rodriguez, Maria J

    2015-01-01

    We present analytic force-free solutions modeling rotating stars and black holes immersed in the magnetic field of a thin disk that terminates at an inner radius. The solutions are exact in flat spacetime and approximate in Kerr spacetime. The compact object produces a conical jet whose properties carry information about its nature. For example, the jet from a star is surrounded by a current sheet, while that of a black hole is smooth. We compute an effective resistance in each case and compare to the canonical values used in circuit models of energy extraction. These solutions illustrate all of the basic features of the Blandford-Znajek process for energy extraction and jet formation in a clean setting.

  19. Stable gravastars - an alternative to black holes?

    E-Print Network [OSTI]

    Matt Visser; David L. Wiltshire

    2003-12-04

    The "gravastar" picture developed by Mazur and Mottola is one of a very small number of serious challenges to our usual conception of a "black hole". In the gravastar picture there is effectively a phase transition at/ near where the event horizon would have been expected to form, and the interior of what would have been the black hole is replaced by a segment of de Sitter space. While Mazur and Mottola were able to argue for the thermodynamic stability of their configuration, the question of dynamic stability against spherically symmetric perturbations of the matter or gravity fields remains somewhat obscure. In this article we construct a model that shares the key features of the Mazur-Mottola scenario, and which is sufficiently simple for a full dynamical analysis. We find that there are some physically reasonable equations of state for the transition layer that lead to stability.

  20. Phase Structure of Higher Spin Black Holes

    E-Print Network [OSTI]

    Abhishek Chowdhury; Arunabha Saha

    2015-02-12

    We revisit the study of the phase structure of higher spin black holes carried out in arXiv$:1210.0284$ using the "canonical formalism". In particular we study the low as well as high temperature regimes. We show that the Hawking-Page transition takes place in the low temperature regime. The thermodynamically favoured phase changes from conical surplus to black holes and then again to conical surplus as we increase temperature. We then show that in the high temperature regime the diagonal embedding gives the appropriate description. We also give a map between the parameters of the theory near the IR and UV fixed points. This makes the "good" solutions near one end map to the "bad" solutions near the other end and vice versa.

  1. HETEROGENEOUS SHALLOW-SHELF CARBONATE BUILDUPS IN THE PARADOX BASIN, UTAH AND COLORADO: TARGETS FOR INCREASED OIL PRODUCTION AND RESERVES USING HORIZONTAL DRILLING TECHNIQUES

    SciTech Connect (OSTI)

    David E. Eby; Thomas C. Chidsey, Jr.; Kevin McClure; Craig D. Morgan

    2003-07-01

    The Paradox Basin of Utah, Colorado, Arizona, and New Mexico contains nearly 100 small oil fields producing from carbonate buildups within the Pennsylvanian (Desmoinesian) Paradox Formation. These fields typically have one to 10 wells with primary production ranging from 700,000 to 2,000,000 barrels (111,300-318,000 m{sup 3}) of oil per field and a 15 to 20 percent recovery rate. At least 200 million barrels (31.8 million m{sup 3}) of oil will not be recovered from these small fields because of inefficient recovery practices and undrained heterogeneous reservoirs. Several fields in southeastern Utah and southwestern Colorado are being evaluated as candidates for horizontal drilling and enhanced oil recovery from existing vertical wells based upon geological characterization and reservoir modeling case studies. Geological characterization on a local scale is focused on reservoir heterogeneity, quality, and lateral continuity, as well as possible reservoir compartmentalization, within these fields. This study utilizes representative cores, geophysical logs, and thin sections to characterize and grade each field's potential for drilling horizontal laterals from existing development wells. The results of these studies can be applied to similar fields elsewhere in the Paradox Basin and the Rocky Mountain region, the Michigan and Illinois Basins, and the Midcontinent region. This report covers research activities for the second half of the third project year (October 6, 2002, through April 5, 2003). The primary work included describing and mapping regional facies of the upper Ismay and lower Desert Creek zones of the Paradox Formation in the Blanding sub-basin, Utah. Regional cross sections show the development of ''clean carbonate'' packages that contain all of the productive reservoir facies. These clean carbonates abruptly change laterally into thick anhydrite packages that filled several small intra-shelf basins in the upper Ismay zone. Examination of upper Ismay cores identified seven depositional facies: open marine, middle shelf, inner shelf/tidal flat, bryozoan mounds, phylloid-algal mounds, quartz sand dunes, and anhydritic salinas. Lower Desert Creek facies include open marine, middle shelf, protomounds/collapse breccia, and phylloid-algal mounds. Mapping the upper Ismay zone facies delineates very prospective reservoir trends that contain porous, productive buildups around the anhydrite-filled intra-shelf basins. Facies and reservoir controls imposed by the anhydritic intra-shelf basins should be considered when selecting the optimal location and orientation of any horizontal drilling from known phylloidalgal reservoirs to undrained reserves, as well as identifying new exploration trends. Although intra-shelf basins are not present in the lower Desert Creek zone of the Blanding sub-basin, drilling horizontally along linear shoreline trends could also encounter previously undrilled, porous intervals and buildups. Technology transfer activities consisted of a technical presentation at a Class II Review conference sponsored by the National Energy Technology Laboratory at the Center for Energy and Economic Diversification in Odessa, Texas. The project home page was updated on the Utah Geological Survey Internet web site.

  2. Comparing quantum black holes and naked singularities

    E-Print Network [OSTI]

    T. P. Singh

    2000-12-21

    There are models of gravitational collapse in classical general relativity which admit the formation of naked singularities as well as black holes. These include fluid models as well as models with scalar fields as matter. Even if fluid models were to be regarded as unphysical in their matter content, the remaining class of models (based on scalar fields) generically admit the formation of visible regions of finite but arbitrarily high curvature. Hence it is of interest to ask, from the point of view of astrophysics, as to what a stellar collapse leading to a naked singularity (or to a visible region of very high curvature) will look like, to a far away observer. The emission of energy during such a process may be divided into three phases - (i) the classical phase, during which matter and gravity can both be treated according to the laws of classical physics, (ii) the semiclassical phase, when gravity is treated classically but matter behaves as a quantum field, and (iii) the quantum gravitational phase. In this review, we first give a summary of the status of naked singularities in classical relativity, and then report some recent results comparing the semiclassical phase of black holes with the semiclassical phase of spherical collapse leading to a naked singularity. In particular, we ask how the quantum particle creation during the collapse leading to a naked singularity compares with the Hawking radiation from a star collapsing to form a black hole. It turns out that there is a fundamental difference between the two cases. A spherical naked star emits only about one Planck energy during its semiclassical phase, and the further evolution can only be determined by the laws of quantum gravity. This contrasts with the semiclassical evaporation of a black hole.

  3. Electromagnetic wave scattering by Schwarzschild black holes

    E-Print Network [OSTI]

    Luís C. B. Crispino; Sam R. Dolan; Ednilton S. Oliveira

    2009-05-20

    We analyze the scattering of a planar monochromatic electromagnetic wave incident upon a Schwarzschild black hole. We obtain accurate numerical results from the partial wave method for the electromagnetic scattering cross section, and show that they are in excellent agreement with analytical approximations. The scattering of electromagnetic waves is compared with the scattering of scalar, spinor and gravitational waves. We present a unified picture of the scattering of all massless fields for the first time.

  4. Lagrangian perfect fluids and black hole mechanics

    E-Print Network [OSTI]

    Vivek Iyer

    1996-10-15

    The first law of black hole mechanics (in the form derived by Wald), is expressed in terms of integrals over surfaces, at the horizon and spatial infinity, of a stationary, axisymmetric black hole, in a diffeomorphism invariant Lagrangian theory of gravity. The original statement of the first law given by Bardeen, Carter and Hawking for an Einstein-perfect fluid system contained, in addition, volume integrals of the fluid fields, over a spacelike slice stretching between these two surfaces. When applied to the Einstein-perfect fluid system, however, Wald's methods yield restricted results. The reason is that the fluid fields in the Lagrangian of a gravitating perfect fluid are typically nonstationary. We therefore first derive a first law-like relation for an arbitrary Lagrangian metric theory of gravity coupled to arbitrary Lagrangian matter fields, requiring only that the metric field be stationary. This relation includes a volume integral of matter fields over a spacelike slice between the black hole horizon and spatial infinity, and reduces to the first law originally derived by Bardeen, Carter and Hawking when the theory is general relativity coupled to a perfect fluid. We also consider a specific Lagrangian formulation for an isentropic perfect fluid given by Carter, and directly apply Wald's analysis. The resulting first law contains only surface integrals at the black hole horizon and spatial infinity, but this relation is much more restrictive in its allowed fluid configurations and perturbations than that given by Bardeen, Carter and Hawking. In the Appendix, we use the symplectic structure of the Einstein-perfect fluid system to derive a conserved current for perturbations of this system: this current reduces to one derived ab initio for this system by Chandrasekhar and Ferrari.

  5. Economic aspects of black bases in Texas 

    E-Print Network [OSTI]

    Schoen, Wayne Ayron

    1976-01-01

    such that an optimal asphalt content for each aggregate type could be determined. Test method Tex-126-E requires that the 6-inches in diameter by 8-inches in height samples be failed in unconfined compression and from these results an optimum asphalt content... procedure and two would not. The purpose of the vacuum saturation procedure was to determine the effect of water on the black base mixtures. At present, an acceptable national standard vacuum saturation procedure does not exist. Therefore, a test...

  6. Big Bang Nucleosynthesis and Primordial Black Holes

    E-Print Network [OSTI]

    C. Sivaram; Kenath Arun

    2010-06-28

    There are ongoing efforts in detecting Hawking radiation from primordial black holes (PBH) formed during the early universe. Here we put an upper limit on the PBH number density that could have been formed prior to the big bang nucleosynthesis era, based on the constraint that the PBH evaporation energy consisting of high energy radiation not affect the observed abundances' of elements, by disintegrating the nuclei.

  7. Interior of Black Holes and Information Recovery

    E-Print Network [OSTI]

    Hikaru Kawai; Yuki Yokokura

    2015-09-28

    We analyze time evolution of a collapsing matter from a point of view that black holes evaporate by nature. We first consider a spherical thin shell that falls in the metric of an evaporating Schwarzschild black hole whose radius $a(t)$ decreases as $\\frac{da(t)}{dt}=-\\frac{2\\sigma(a(t))}{a(t)^2}$. The shell can never reach $a(t)$, but it approaches $a(t)+\\frac{2\\sigma(a(t))}{a(t)}$ in the time scale $\\sim a(t)$. Then the radiation from the hole is extremely weakened because of the large redshift caused by the shell. This time, however, the shell itself starts to radiate and exhausts energy. After that, the hole starts to radiate again. We can repeat this argument recursively because the motion of a shell in a spherically symmetric system is independent of the outside. In this way we can analyze a spherically symmetric collapsing matter with a general continuous distribution, and find that it evaporates without forming a trapped region. If the theory has considerably more species of matter fields, the trans-Planckian problems are avoided. There is a clear boundary at $r=a+\\frac{2\\sigma}{a}$ as the surface of the object. Although the matter distribution inside the object depends on the initial data, from the outside it looks almost the same as a conventional black hole. A strong angular pressure is induced by the Hawking radiation, because of which the matter loses energy when it collapses. We then discuss how the information of the matter is recovered in this picture. Next we consider a black hole that is adiabatically grown from a small one in the heat bath, and obtain the interior metric. We show that it is the self-consistent solution of $G_{\\mu\

  8. Flip-flopping binary black holes

    E-Print Network [OSTI]

    Carlos O. Lousto; James Healy

    2015-03-14

    We study binary spinning black holes to display the long term individual spin dynamics. We perform a full numerical simulation starting at an initial proper separation of $d\\approx25M$ between equal mass holes and evolve them down to merger for nearly 48 orbits, 3 precession cycles, and half of a flip-flop cycle. The simulation lasts for $t=20000M$ and displays a total change in the orientation of the spin of one of the black holes from initially aligned with the orbital angular momentum to a complete anti-alignment after half of a flip-flop cycle. We compare this evolution with an integration of the 3.5 Post-Newtonian equations of motion and spin evolution to show that this process continuously flip-flops the spin during the lifetime of the binary until merger. We also provide lower order analytic expressions for the maximum flip-flop angle and frequency. We discuss the effects this dynamics may have on spin growth in accreting binaries and on the observational consequences for galactic and supermassive binary black holes.

  9. Thermodynamics and Luminosities of Rainbow Black Holes

    E-Print Network [OSTI]

    Mu, Benrong; Yang, Haitang

    2015-01-01

    Doubly special relativity (DSR) is an effective model for encoding quantum gravity in flat spacetime. As a result of the nonlinearity of the Lorentz transformation, the energy-momentum dispersion relation is modified. One simple way to import DSR to curved spacetime is \\textquotedblleft Gravity's rainbow", where the spacetime background felt by a test particle would depend on its energy. Focusing on the \\textquotedblleft Amelino-Camelia dispersion relation" which is $E^{2}=m^{2}+p^{2}\\left[ 1-\\eta\\left( E/m_{p}\\right) ^{n}\\right] $ with $n>0$, we investigate the thermodynamical properties of a Schwarzschild black hole and a static uncharged black string for all possible values of $\\eta$ and $n$ in the framework of rainbow gravity. It shows that there are non-vanishing minimum masses for these two black holes in the cases with $\\eta<0$ and $n\\geq2$. Considering effects of rainbow gravity on both the Hawking temperature and radius of the event horizon, we use the geometric optics approximation to compute lum...

  10. Rotating black hole solutions with quintessential energy

    E-Print Network [OSTI]

    Toshmatov, Bobir; Ahmedov, Bobomurat

    2015-01-01

    Quintessential dark energy with density $\\rho$ and pressure $p$ is governed by an equation of state of the form $p=-\\omega_{q}\\rho$ with the quintessential parameter $\\omega_q\\in(-1;-1/3)$. We derive the geometry of quintessential rotating black holes, generalizing thus the Kerr spacetimes. Then we study the quintessential rotating black hole spacetimes with the special value of $\\omega_q = -2/3$ when the resulting formulae are simple and easily tractable. We show that such special spacetimes can exist for dimensionless quintessential parameter $c<1/6$ and determine the critical rotational parameter $a_0$ separating the black hole and naked singularity spacetime in dependence on the quintessential parameter $c$. For the spacetimes with $\\omega_q = 2/3$ we present the integrated geodesic equations in separated form and study in details the circular geodetical orbits. We give radii and parameters of the photon circular orbits, marginally bound and marginally stable orbits. We stress that the outer boundary o...

  11. Adaptive Finite Elements and Colliding Black Holes

    E-Print Network [OSTI]

    Douglas N. Arnold; Arup Mukherjee; Luc Pouly

    1997-09-15

    According to the theory of general relativity, the relative acceleration of masses generates gravitational radiation. Although gravitational radiation has not yet been detected, it is believed that extremely violent cosmic events, such as the collision of black holes, should generate gravity waves of sufficient amplitude to detect on earth. The massive Laser Interferometer Gravitational-wave Observatory, or LIGO, is now being constructed to detect gravity waves. Consequently there is great interest in the computer simulation of black hole collisions and similar events, based on the numerical solution of the Einstein field equations. In this note we introduce the scientific, mathematical, and computational problems and discuss the development of a computer code to solve the initial data problem for colliding black holes, a nonlinear elliptic boundary value problem posed in an unbounded three dimensional domain which is a key step in solving the full field equations. The code is based on finite elements, adaptive meshes, and a multigrid solution process. Here we will particularly emphasize the mathematical and algorithmic issues arising in the generation of adaptive tetrahedral meshes.

  12. Probing Dark Energy with Black Hole Binaries

    E-Print Network [OSTI]

    Laura Mersini-Houghton; Adam Kelleher

    2008-08-25

    The equation of state (EoS) of dark energy $w$ remains elusive despite enormous experimental efforts to pin down its value and its time variation. Yet it is the single most important handle we have in our understanding of one of the most mysterious puzzle in nature, dark energy. This letter proposes a new method for measuring the EoS of dark energy by using the gravitational waves (GW) of black hole binaries. The method described here offers an alternative to the standard way of large scale surveys. It is well known that the mass of a black hole changes due to the accretion of dark energy but at an extremely slow rate. However, a binary of supermassive black holes (SBH) radiates gravitational waves with a power proportional to the masses of these accreting stars and thereby carries information on dark energy. These waves can propagate through the vastness of structure in the universe unimpeded. The orbital changes of the binary, induced by the energy loss from gravitational radiation, receive a large contribution from dark energy accretion. This contribution is directly proportional to $(1+w)$ and is dominant for SBH binaries with separation $R \\ge 1000$ parsec, thereby accelerating the merging process for $w > -1$ or ripping the stars apart for phantom dark energy with $w < -1$. Such orbital changes, therefore $w$, can be detected with LIGO and LISA near merging time, or with X-ray and radio measurements of Chandra and VLBA experiments.

  13. Accretion Processes On a Black Hole

    E-Print Network [OSTI]

    Sandip K. Chakrabarti

    1996-05-03

    We describe astrophysical processes around a black hole keeping primarily the physics of accretion in mind. In Section 1, we briefly discuss the formation, evolution and detection of black holes. We also discuss the difference of flow properties around a black hole and a Newtonian star. In Section 2, we present past and present developments in the study of spherically accreting flows. We study the properties of Bondi flow with and without radiative transfer. In the presence of significant angular momentum, which is especially true in a binary system, matter will be accreted as a thin Keplerian disk. In Section 3, we discuss a large number of models of these disks including the more popular standard disk model. We present magnetized disk models as well. Since the angular momentum is high in these systems, rotational motion is the most dominant component compared to the radial or the vertical velocity components. In Section 4, we study thick disk models which are of low angular momentum but still have no significant radial motion. The accretion rates could be very high causing the flow to become radiation dominated and the disk to be geometrically thick. For low accretion rates, ion pressure supported disks are formed. In Section 5, we extensively discuss the properties of transonic flows which has with sub-Keplerian angular momentum. In the absence of shock discontinuities, these sub-Keplerian flows are basically advecting, similar to Bondi flows, close to the black holes, though far away they match Keplerian or sub-Keplerian disks. In presence of shocks, the post-shock flow becomes rotation dominated similar to thick disks. In Section 6, we present results of important numerical simulations of accretion flows. Significant results from the studies of evolution of viscous transonic flows are reported. In Section 7, we discuss some observational evidences of the black hole accretion. We also present a detailed model of a generalized accretion disk and present its spectra and compare with observations. In Section 8, we summarize the review and make concluding remarks.

  14. Black Carbon Emissions by Rocket Engines Types of rocket engines Emissions

    E-Print Network [OSTI]

    Toohey, Darin W.

    Black Carbon Emissions by Rocket Engines Types of rocket engines Emissions Liquid Hydrogen. Note: Black carbon does not deplete ozone. What happens is the black carbon emissions from the rocket. Other black carbon emissions: The number one contributor to black carbon is burning biomass. Also

  15. Thermodynamic Product Formula for Taub-NUT Black Hole

    E-Print Network [OSTI]

    Parthapratim Pradhan

    2015-08-20

    We derive various important thermodynamic relations of the inner and outer horizon in the background of Taub-NUT(Newman-Unti-Tamburino) black hole in four dimensional \\emph{Lorentzian geometry}. We compare these properties with the properties of Reissner Nordstr{\\o}m black hole. We compute \\emph{area product, area sum, area minus and area division} of black hole horizons. We show that they all are not universal quantities. Based on these relations, we compute the area bound of all horizons. From area bound, we derive entropy bound and irreducible mass bound for both the horizons. We further study the stability of such black hole by computing the specific heat for both the horizons. It is shown that due to negative specific heat the black hole is thermodynamically unstable. All these calculations might be helpful to understanding the nature of black hole entropy both \\emph{interior} and exterior at the microscopic level.

  16. Thermodynamic Product Formula for Taub-NUT Black Hole

    E-Print Network [OSTI]

    Pradhan, Parthapratim

    2015-01-01

    We derive various important thermodynamic relations of the inner and outer horizon in the background of Taub-NUT(Newman-Unti-Tamburino) black hole in four dimensional \\emph{Lorentzian geometry}. We compare these properties with the properties of Reissner Nordstr{\\o}m black hole. We compute \\emph{area product, area sum, area minus and area division} of black hole horizons. We show that they all are not universal quantities. Based on these relations, we compute the area bound of all horizons. From area bound, we derive entropy bound and irreducible mass bound for both the horizons. We further study the stability of such black hole by computing the specific heat for both the horizons. It is shown that due to negative specific heat the black hole is thermodynamically unstable. All these calculations might be helpful to understanding the nature of black hole entropy both \\emph{interior} and exterior at the microscopic level.

  17. Destroying Kerr-Sen black holes with test particles

    E-Print Network [OSTI]

    Haryanto M. Siahaan

    2015-12-05

    By neglecting the self-force, self-energy, and radiative effects, it has been shown that an extremal or near-extremal Kerr-Newman black hole can turn to a naked singularity when it captures charged massive test particles with angular momentum. A straightforward question then arises, do charged and rotating black holes in string theory possess the same property? In this paper we adopt the Wald's gedanken experiment in an effort to destroy a Kerr-Newman black hole's horizon to the case of (near)-extremal Kerr-Sen black holes. We find that feeding a test particle into a (near)-extremal Kerr-Sen black hole could lead to a violation of the extremal bound for such black hole.

  18. Adaptive computation of gravitational waves from black hole interactions

    E-Print Network [OSTI]

    Philippos Papadopoulos; Edward Seidel; Lee Wild

    1998-02-27

    We construct a class of linear partial differential equations describing general perturbations of non-rotating black holes in 3D Cartesian coordinates. In contrast to the usual approach, a single equation treats all radiative $\\ell -m$ modes simultaneously, allowing the study of wave perturbations of black holes with arbitrary 3D structure, as would be present when studying the full set of nonlinear Einstein equations describing a perturbed black hole. This class of equations forms an excellent testbed to explore the computational issues of simulating black spacetimes using a three dimensional adaptive mesh refinement code. Using this code, we present results from the first fully resolved 3D solution of the equations describing perturbed black holes. We discuss both fixed and adaptive mesh refinement, refinement criteria, and the computational savings provided by adaptive techniques in 3D for such model problems of distorted black holes.

  19. Thermodynamics of Charged Lovelock - AdS Black Holes

    E-Print Network [OSTI]

    Prasobh C. B.; Jishnu Suresh; V. C. Kuriakose

    2015-10-16

    We investigate the thermodynamic behavior of maximally symmetric charged, asymptotically AdS black hole solutions of Lovelock gravity. We explore the thermodynamic stability of such solutions by the ordinary method of calculating the specific heat of the black holes and investigating its divergences which signal second order phase transitions between black hole states. We then utilize the methods of thermodynamic geometry of black hole spacetimes in order to explain the origin of these points of divergence. We calculate the curvature scalar corresponding to a Legendre-invariant thermodynamic metric of these spacetimes and find that the divergences in the black hole specific heat correspond to singularities in the thermodynamic phase space. We also calculate the area spectrum for large black holes in the model by applying the Bohr-Sommerfeld quantization to the adiabatic invariant calculated for the spacetime.

  20. Galaxy bulges and their massive black holes: a review

    E-Print Network [OSTI]

    Alister W. Graham

    2015-02-17

    With references to both key and oft-forgotten pioneering works, this article starts by presenting a review into how we came to believe in the existence of massive black holes at the centres of galaxies. It then presents the historical development of the near-linear (black hole)-(host spheroid) mass relation, before explaining why this has recently been dramatically revised. Past disagreement over the slope of the (black hole)-(velocity dispersion) relation is also explained, and the discovery of sub-structure within the (black hole)-(velocity dispersion) diagram is discussed. As the search for the fundamental connection between massive black holes and their host galaxies continues, the competing array of additional black hole mass scaling relations for samples of predominantly inactive galaxies are presented.

  1. A Quantum Material Model of Static Schwarzschild Black Holes

    E-Print Network [OSTI]

    S. -T. Sung

    1997-03-16

    A quantum-mechanical prescription of static Einstein field equation is proposed in order to construct the matter-metric eigen-states in the interior of a static Schwarzschild black hole where the signature of space-time is chosen as (--++). The spectrum of the quantum states is identified to be the integral multiples of the surface gravity. A statistical explanation of black hole entropy is given and a quantisation rule for the masses of Schwarzschild black holes is proposed.

  2. Classical and Quantum Properties of Liouville Black Holes

    E-Print Network [OSTI]

    R. B. Mann

    1994-04-25

    Black hole spacetimes can arise when a Liouville field is coupled to two- dimensional gravity. Exact solutions are obtained both classically and when quantum corrections due to back reaction effects are included. The black hole temperature depends upon the mass and the thermodynamic limit breaks down before evaporation of the black hole is complete, indicating that higher-loop effects must be included for a full description of the process.

  3. A Variational Principle for Asymptotically Randall-Sundrum Black Holes

    E-Print Network [OSTI]

    Scott Fraser; Douglas M. Eardley

    2015-07-28

    We prove the following variational principle for asymptotically Randall-Sundrum (RS) black holes, based on the first law of black hole mechanics: Instantaneously static initial data that extremizes the mass yields a static black hole, for variations at fixed apparent horizon area, AdS curvature length, cosmological constant, brane tensions, and RS brane warp factors. This variational principle is valid with either two branes (RS1) or one brane (RS2), and is applicable to variational trial solutions.

  4. Thermal Fluctuations in a Charged AdS Black Hole

    E-Print Network [OSTI]

    Pourhassan, B

    2015-01-01

    In this paper, we will analyze the effects of thermal fluctuations on a charged AdS black hole. This will be done by analyzing the corrections to black hole thermodynamics due to these thermal fluctuations. We will demonstrate that the entropy of this black hole get corrected by logarithmic term. We will also calculate other corrections to other important thermodynamic quantities for this black hole. Finally, we will use the corrected value of the specific heat to analyze the phase transition in this system.

  5. Thermal Fluctuations in a Charged AdS Black Hole

    E-Print Network [OSTI]

    B. Pourhassan; Mir Faizal

    2015-08-12

    In this paper, we will analyze the effects of thermal fluctuations on a charged AdS black hole. This will be done by analyzing the corrections to black hole thermodynamics due to these thermal fluctuations. We will demonstrate that the entropy of this black hole get corrected by logarithmic term. We will also calculate other corrections to other important thermodynamic quantities for this black hole. Finally, we will use the corrected value of the specific heat to analyze the phase transition in this system.

  6. L.A. Rebellion: Creating a New Black Cinema

    E-Print Network [OSTI]

    Sheppard, Samantha Noelle

    2011-01-01

    enriching and enlightening cinematic history and legacy ofalternative, and authentic cinematic depictions of BlackL.A Rebellion’s “fabulous cinematic libera- tion brought off

  7. Noncommutative Black-Body Radiation: Implications On Cosmic Microwave Background

    E-Print Network [OSTI]

    Amir H. Fatollahi; Maryam Hajirahimi

    2006-07-12

    Including loop corrections, black-body radiation in noncommutative space is anisotropic. A direct implication of possible space noncommutativity on the Cosmic Microwave Background map is argued.

  8. Black Pine Engineering Wins Clean Energy Trust Clean Energy Challenge...

    Energy Savers [EERE]

    the National Clean Energy Business Plan Competition Explore the Energy Innovation Portal Last week the student team of Black Pine Engineering from Michigan State University...

  9. Modelled Black Carbon Radiative Forcing and Atmospheric Lifetime...

    Office of Scientific and Technical Information (OSTI)

    AeroCom Phase II Constrained by Aircraft Observations Black carbon (BC) aerosols absorb solar radiation, and are generally held to exacerbate global warming through exerting a...

  10. Lovelock black hole thermodynamics in a string cloud model

    E-Print Network [OSTI]

    Lee, Tae-Hun; Maharaj, Sunil D; Baboolal, Dharmanand

    2015-01-01

    The Lovelock theory is an extension of general relativity to higher dimensions. We study the Lovelock black hole for a string cloud model in arbitrary dimensional spacetime, and in turn also analyze its thermodynamical properties. Indeed, we compute the mass, temperature and entropy of the black hole and also perform a thermodynamical stability analysis. The phase structure suggests that the Hawking-Page phase transition is achievable. It turns out that the presence of the Lovelock terms and/or background string cloud completely changes the black hole thermodynamics. Interestingly, the entropy of a black hole is unaffected due to a background string cloud, but has a correction term due to Lovelock gravity.

  11. Thermodynamics of rotating black holes in conformal gravity

    E-Print Network [OSTI]

    Kamvar, Negin; Soroushfar, Saheb

    2015-01-01

    In this paper we consider a metric of a rotating black hole in conformal gravity. We calculate the thermodynamical quantities for this rotating black hole including Hawking temperature and entropy in four dimensional space-time, as we obtain the effective value of Komar angular momentum. The result is valid on the event horizon of the black hole, and at any radial distance out of it. Also we verify that the first law of thermodynamics will be held for this type of black hole.

  12. Minimal Length Effects on Tunnelling from Spherically Symmetric Black Holes

    E-Print Network [OSTI]

    Benrong Mu; Peng Wang; Haitang Yang

    2015-01-24

    In this paper, we investigate effects of the minimal length on quantum tunnelling from spherically symmetric black holes using the Hamilton-Jacobi method incorporating the minimal length. We first derive the deformed Hamilton-Jacobi equations for scalars and fermions, both of which have the same expressions. The minimal length correction to the Hawking temperature is found to depend on the black hole's mass and the mass and angular momentum of emitted particles. Finally, we calculate a Schwarzschild black hole's luminosity and find the black hole evaporates to zero mass in infinite time.

  13. Minimal Length Effects on Tunnelling from Spherically Symmetric Black Holes

    E-Print Network [OSTI]

    Mu, Benrong; Yang, Haitang

    2015-01-01

    In this paper, we investigate effects of the minimal length on quantum tunnelling from spherically symmetric black holes using the Hamilton-Jacobi method incorporating the minimal length. We first derive the deformed Hamilton-Jacobi equations for scalars and fermions, both of which have the same expressions. The minimal length correction to the Hawking temperature is found to depend on the black hole's mass and the mass and angular momentum of emitted particles. Finally, we calculate a Schwarzschild black hole's luminosity and find the black hole evaporates to zero mass in infinite time.

  14. Energy Distribution of a Charged Regular Black Hole

    E-Print Network [OSTI]

    Irina Radinschi

    2000-11-20

    We calculate the energy distribution of a charged regular black hole by using the energy-momentum complexes of Einstein and M{\\o}ller.

  15. Paleoecology of the Devonian-Mississippian black-shale sequence...

    Office of Scientific and Technical Information (OSTI)

    54 ENVIRONMENTAL SCIENCES; 03 NATURAL GAS; 04 OIL SHALES AND TAR SANDS; BLACK SHALES; GEOLOGY; PALEONTOLOGY; KENTUCKY; DEVONIAN PERIOD; FOSSILS; GEOLOGIC HISTORY; BITUMINOUS...

  16. Free fall onto evaporating black holes at the quantum limit

    E-Print Network [OSTI]

    Maurice H. P. M. van Putten

    2015-11-11

    Black hole space times evaporate in discrete steps due to remarkably slow Hawking radiation. We here identify evaporation with essentially extremal states at the limit of quantum computation, performing $2.7\\times 10^{79}$ bit calculations per photon emission in a one solar mass black hole. During evaporation, particles in free fall co-evolve satisfying $EM=$constant, where $E$ and $M$ denote the total mass energy-at-infinity of the particle and, respectively, black hole. Particles are hereby increasingly entangled with the black hole space-time over the course of its evaporation.

  17. T-602: BlackBerry Enterprise Server Input Validation Flaw in...

    Broader source: Energy.gov (indexed) [DOE]

    BlackBerry Enterprise Server Input Validation Flaw in BlackBerry Web Desktop Manager Permits Cross-Site Scripting Attacks PLATFORM: BlackBerry Enterprise Server Express versions...

  18. Extraneous Carbon Assessments in Radiocarbon Measurements of Black Carbon in Environmental Matrices

    E-Print Network [OSTI]

    Coppola, Alysha; Ziolkowski, L. A.; Druffel, E. R. M.

    2013-01-01

    rived (black/elemental) carbon in soils and sediments usingbon measurements of black carbon in aerosols and oceanMWI, Noack AG. 2000. Black carbon in soils and sediments:

  19. T-579: BlackBerry Device Software Bug in WebKit Lets Remote Users...

    Broader source: Energy.gov (indexed) [DOE]

    information stored on the file system of the BlackBerry smartphone. The following devices are affected: * BlackBerry Bold 9650 smartphone * BlackBerry Bold 9700 smartphone...

  20. I am Black AND Jewish: Black Jewish Women’s Experiences in “White” Jewish Communities in Brazil

    E-Print Network [OSTI]

    Gondek, Abby S.

    2008-01-01

    ideal after scientific racism. Black into white: Race andbut continues to enact racism and anti-Semitism (Barcelos,context demonstrates why racism (including anti-Semitism) is

  1. Warrior dreams: playing Scotsmen in mainland Europe, 1945 – 2010 

    E-Print Network [OSTI]

    Hesse, David Johannes

    2011-11-22

    At the beginning of the twenty first century, thousands of adult Europeans are playing Scotsmen. They dress up in kilts and tartan, parade in military-style bagpipe bands, toss tree trunks at Highland Games, commemorate ...

  2. Vinyasa Flow Awaken your inner warrior! This dynamic flow infuses

    E-Print Network [OSTI]

    -1pm Informal Recreation Open Gym Basketball-6/17-8/14 Gym 147 Monday's and Wednesdays: 12-1pm #12;.sfsu.edu/~recsport Gentle Hatha Yoga 12-1pm (BH6) -Jacalyn Dance-Begins 6/17 12-1pm (Gym 100J) -Mo PIYO® 12-1pm (Gym 149) -Adair 6/10-7/23 Vinyasa Flow 12-1pm (BH6) -Jeff ZUMBA®-Begins 6/18 12-1pm (Gym 100) -Erika- XL Strength

  3. Ancient Warriors and the Origin of Chinese Purple

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D B L O O D S TAPropaneandAn3 Table 3.InnovationAncient

  4. Inheritance of Black Pericarp Trait in Sorghum 

    E-Print Network [OSTI]

    Hill, Kathleen Marie

    2014-09-18

    high and low pH levels, making it a viable candidate for use as a natural food colorant and preservative (Pfeiffer, 2014). Sorghum is also naturally gluten free (Pfeiffer, 2014) making it an excellent wheat substitute for those who suffer from Celiac... as antioxidants (Dlamini et al., 2007) and in the body, ward off free radicals that lead to disease (Rajendran, et. al., 2014). Sorghum, 5 compared to other cereals, has the highest level of antioxidants (Pfeiffer, 2014). In fact, black sorghum has levels...

  5. Radion clouds around evaporating black holes

    E-Print Network [OSTI]

    J. R. Morris

    2009-09-03

    A Kaluza-Klein model, with a matter source associated with Hawking radiation from an evaporating black hole, is used to obtain a simple form for the radion effective potential. The environmental effect generally causes a matter-induced shift of the radion vacuum, resulting in the formation of a radion cloud around the hole. There is an albedo due to the radion cloud, with an energy dependent reflection coefficient that depends upon the size of the extra dimensions and the temperature of the hole.

  6. Black Kernel and White Tip of Rice. 

    E-Print Network [OSTI]

    Martin, Alan L. (Alan La Mott); Altstatt, G. E. (George E.)

    1940-01-01

    . Amer. Jour. Bot. 26 :P46-852. 1939. Taubenhaus, J. J. Rice diseases. In 50th Ann. Rpt. Tex. Agr. Sta., pp. 114-115. 1937. Taubenhaus, J. J., Altstatt, G. E., and Wyche, R. H. Black kernel of rice. In 4Fth Ann. Rpt. Texas Am. Exp. Sta., p. 94. 1935.... Taubenhaus, J. J., and Wyche, R. H. Rice Diseases. In 49th Ann. Rpt. Texas Agr. Exp. Sta., pp. 109-111. 1936. Tullis, E. C. Fungi isolated from discolored rice kernels. U. S. Dept. Agr. Tech. Bull. 540. 1936. ...

  7. Definition:Black Liquor | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTIONRobertsdale, Alabama (UtilityInstruments IncMississippi: EnergyS A IndustriasNewDefianceBlack Liquor

  8. Black Hills Power Inc | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmental JumpInformationBio-Gas Technologies, LLCMichigan:Earth, Wisconsin:Black Hills

  9. BlackGold Biofuels | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX ECoop IncIowaWisconsin:Pontiac Biomass Facility JumpII Jump to:BitworksFarmBlackGold

  10. Cemex Black Mountain Quarry | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX ECoopButte County,Camilla,Thermal Gradient Holes JumpHills WindBlack Mountain Quarry

  11. Paleoecology and Geochemistry of the Upper Kellwasser Black Shale and Extinction Event

    E-Print Network [OSTI]

    Haddad, Emily Elizabeth

    2015-01-01

    A.D. , 2009. When do black shales tell molybdenum isotopeand redox facies in core shales of Upper PennsylvanianB.B. , 1994. Marine black shales: depositional mechanisms

  12. Exact quasinormal modes for a special class of black holes

    E-Print Network [OSTI]

    Julio Oliva; Ricardo Troncoso

    2010-03-11

    Analytic exact expressions for the quasinormal modes of scalar and electromagnetic perturbations around a special class of black holes are found in d\\ge3 dimensions. It is shown that, the size of the black hole provides a bound for the angular momentum of the perturbation. Quasinormal modes appear when this bound is fulfilled, otherwise the excitations become purely damped.

  13. Moduli Vacuum Bubbles Produced by Evaporating Black Holes

    E-Print Network [OSTI]

    J. R. Morris

    2007-08-14

    We consider a model with a toroidally compactified extra dimension giving rise to a temperature-dependent 4d effective potential with one-loop contributions due to the Casimir effect, along with a 5d cosmological constant. The forms of the effective potential at low and high temperatures indicates a possibility for the formation of a domain wall bubble, formed by the modulus scalar field, surrounding an evaporating black hole. This is viewed as an example of a recently proposed black hole vacuum bubble arising from matter-sourced moduli fields in the vicinity of an evaporating black hole [D. Green, E. Silverstein, and D. Starr, Phys. Rev. D74, 024004 (2006), arXiv:hep-th/0605047]. The black hole bubble can be highly opaque to lower energy particles and photons, and thereby entrap them within. For high temperature black holes, there may also be a symmetry-breaking black hole bubble of false vacuum of the type previously conjectured by Moss [I.G. Moss, Phys. Rev. D32,1333 (1985)], tending to reflect low energy particles from its wall. A double bubble composed of these two different types of bubble may form around the black hole, altering the hole's emission spectrum that reaches outside observers. Smaller mass black holes that have already evaporated away could have left vacuum bubbles behind that contribute to the dark matter.

  14. Modified Black Hole with Polar Jet and Vortex

    E-Print Network [OSTI]

    T. Tmmalm

    2001-12-06

    There are many models relating an accretion disk of Black Hole to jet outflow. The herein heuristic model describes the continuation of an external accretion disk to an internal accretion disk for less than Black Hole horizon, and subsequent polar jet outflow along polar axis out of polar vortex wherein the event horizon is no longer descriptive.

  15. Pair Production of Topological anti de Sitter Black Holes

    E-Print Network [OSTI]

    R. B. Mann

    1996-07-28

    The pair creation of black holes with event horizons of non-trivial topology is described. The spacetimes are all limiting cases of the cosmological $C$ metric. They are generalizations of the $(2+1)$ dimensional black hole and have asymptotically anti de Sitter behaviour. Domain walls instantons can mediate their pair creation for a wide range of mass and charge.

  16. Analysis of spherically symmetric black holes in Braneworld models

    E-Print Network [OSTI]

    A. B. Pavan

    2010-05-25

    Research on black holes and their physical proprieties has been active on last 90 years. With the appearance of the String Theory and the Braneworld models as alternative descriptions of our Universe, the interest on black holes, in these context, increased. In this work we studied black holes in Braneworld models. A class of spherically symmetric black holes is investigaded as well its stability under general perturbations. Thermodynamic proprieties and quasi-normal modes are discussed. The black holes studied are the SM (zero mass) and CFM solutions, obtained by Casadio {\\it et al.} and Bronnikov {\\it et al.}. The geometry of bulk is unknown. However the Campbell-Magaard Theorem guarantees the existence of a 5-dimensional solution in the bulk whose projection on the brane is the class of black holes considered. They are stable under scalar perturbations. Quasi-normal modes were observed in both models. The tail behavior of the perturbations is the same. The entropy upper bound of a body absorved by the black holes studied was calculated. This limit turned out to be independent of the black hole parameters.

  17. Perturbative Approach to the Quasinormal Modes of Dirty Black Holes

    E-Print Network [OSTI]

    P. T. Leung; Y. T. Liu; W. -M. Suen; C. Y. Tam; K. Young

    1999-03-08

    Using a recently developed perturbation theory for uasinormal modes (QNM's), we evaluate the shifts in the real and imaginary parts of the QNM frequencies due to a quasi-static perturbation of the black hole spacetime. We show the perturbed QNM spectrum of a black hole can have interesting features using a simple model based on the scalar wave equation.

  18. Gravitational wave production by rotating primordial black holes

    E-Print Network [OSTI]

    Dong, Ruifeng; Stojkovic, Dejan

    2015-01-01

    In this paper we analyze in detail a rarely discussed question of gravity waves production from evaporating black holes. Evaporating black holes emit gravitons which are at classical level registered as gravity waves. We use the latest constraints on the primordial black hole abundance, and calculate the power emitted in gravitons at the time of their evaporation. We then solve the coupled system of equations that gives us the evolution of the frequency and amplitude of gravity waves during the expansion of the universe. The spectrum of gravitational waves that can be detected today depends on multiple factors: fraction of the total energy density which was occupied by black holes, the epoch in which the black holes are formed, and quantities like mass and angular momentum of evaporating black holes. We conclude that very small primordial black holes which evaporate before the nucleosynthesis emit gravitons whose spectral energy fraction today can be as large as $10^{-5}$. On the other hand, primordial black ...

  19. Accretion onto the First Stellar Mass Black Holes

    E-Print Network [OSTI]

    Marcelo A. Alvarez; John H. Wise; Tom Abel

    2008-11-07

    The first stars in the universe, forming at redshifts z>15 in minihalos with masses of order 10^6 Msun, may leave behind black holes as their remnants. These objects could conceivably serve as "seeds" for much larger black holes observed at redshifts z~6. We study the growth of the remnant black holes through accretion including for the first time the emitted accretion radiation with adaptive mesh refinement cosmological radiation-hydrodynamical simulations. The effects of photo-ionization and heating dramatically affect the accretion flow from large scales, resulting in negligible mass growth of the black hole. We compare cases with the accretion luminosity included and neglected to show that the accretion radiation drastically changes the environment within 100 pc of the black hole, where gas temperatures are increased by an order of magnitude. The gas densities are reduced and further star formation in the same minihalo prevented for the two hundred million years of evolution we followed. These calculations show that even without the radiative feedback included most seed black holes do not gain mass as efficiently as has been hoped for in previous theories, implying that black hole remnants of Pop III stars that formed in minihalos are not likely to be the origin of miniquasars. Most importantly, however, these calculations demonstrate that if early stellar mass black holes are indeed accreting close to the Bondi-Hoyle rate with ten percent efficiency they have a dramatic local effect in regulating star formation in the first galaxies.

  20. Large rotating AdS black holes from fluid mechanics

    E-Print Network [OSTI]

    Sayantani Bhattacharyya; Subhaneil Lahiri; R. Loganayagam; Shiraz Minwalla

    2008-07-25

    We use the AdS/CFT correspondence to argue that large rotating black holes in global AdS(D) spaces are dual to stationary solutions of the relativistic Navier-Stokes equations on S**(D-2). Reading off the equation of state of this fluid from the thermodynamics of non-rotating black holes, we proceed to construct the nonlinear spinning solutions of fluid mechanics that are dual to rotating black holes. In all known examples, the thermodynamics and the local stress tensor of our solutions are in precise agreement with the thermodynamics and boundary stress tensor of the spinning black holes. Our fluid dynamical description applies to large non-extremal black holes as well as a class of large non-supersymmetric extremal black holes, but is never valid for supersymmetric black holes. Our results yield predictions for the thermodynamics of all large black holes in all theories of gravity on AdS spaces, for example, string theory on AdS(5) x S**5 and M theory on AdS(4) x S**7 and AdS(7) x S**4.

  1. Electric Charge in Interaction with Magnetically Charged Black Holes

    E-Print Network [OSTI]

    J. H. Kim; Sei-Hoon Moon

    2007-10-02

    We examine the angular momentum of an electric charge e placed at rest outside a dilaton black hole with magnetic charge Q. The electromagnetic angular momentum which is stored in the electromagnetic field outside the black hole shows several common features regardless of the dilaton coupling strength, though the dilaton black holes are drastically different in their spacetime structure depending on it. First, the electromagnetic angular momentum depends on the separation distance between the two objects and changes monotonically from eQ to 0 as the charge goes down from infinity to the horizon, if rotational effects of the black hole are discarded. Next, as the black hole approaches extremality, however, the electromagnetic angular momentum tends to be independent of the distance between the two objects. It is then precisely $eQ$ as in the electric charge and monopole system in flat spacetime. We discuss why these effects are exhibited and argue that the above features are to hold in widely generic settings including black hole solutions in theories with more complicated field contents, by addressing the no hair theorem for black holes and the phenomenon of field expulsion exhibited by extremal black holes.

  2. A note on regular black holes in a brane world

    E-Print Network [OSTI]

    Neves, J C S

    2015-01-01

    In this work, we show that regular black holes in a Randall-Sundrum-type brane world model are generated by the non-local bulk influence, expressed by a constant parameter in the brane metric, only in the spherical case. In the axial case (black holes with rotation), this influence forbids them.

  3. Pseudomonas sabulinigri sp. nov., isolated from black beach sand

    E-Print Network [OSTI]

    Bae, Jin-Woo

    Pseudomonas sabulinigri sp. nov., isolated from black beach sand Kyoung-Ho Kim,1 Seong Woon Roh,1 , was isolated from black sand collected from Soesoggak, Jeju Island, Korea. Cells grew at 4­37 6C, at pH 5 beach sand, a bacterium was isolated and subjected to taxonomic characterization. On the basis

  4. Accretion Disks Around Black Holes: Twenty Five Years Later

    E-Print Network [OSTI]

    Sandip K. Chakrabarti

    1998-07-10

    We study the progress of the theory of accretion disks around black holes in last twenty five years and explain why advective disks are the best bet in explaining varied stationary and non-stationary observations from black hole candidates. We show also that the recently proposed advection dominated flows are incorrect.

  5. Extracting Energy from Black Hole through Transition Region

    E-Print Network [OSTI]

    Li-Xin Li

    2000-07-24

    A new scenario for extracting energy from a Kerr black hole is proposed. With magnetic field lines connecting plasma particles inside the ergosphere with remote loads, the frame dragging twists the field lines so that energy and angular momentum are extracted from the plasma particles. If the magnetic field is strong enough, the energy extracted from the particles can be so large that the particles have negative energy as they fall into the black hole. So effectively the energy is extracted from the black hole. The particles inside the ergosphere can be continuously replenished with accretion from a disk surrounding the black hole, so a transition region with sufficient amount of plasma is formed between the black hole's horizon and the inner edge of the disk. Thus the energy can be continuously extracted from the black hole through the transition region. This may be the most efficient way for extracting energy from a Kerr black hole: in principle almost all of the rotational energy (up to $\\approx 29%$ of the total energy of the black hole) can be extracted.

  6. Electromagnetic Excitation of Rotating Black Holes and Relativistic Jets

    E-Print Network [OSTI]

    A. Burinskii; E. Elizalde; S. R. Hildebrandt; G. Magli

    2006-10-02

    We show that electromagnetic excitations of rotating black holes can lead to the appearance of narrow singular beams which break up the black hole horizon forming a tube-like region which connects the interior and exterior. It is argued that this effect may be at the origin of jet formation.

  7. Is the Universe the only existing Black Hole?

    E-Print Network [OSTI]

    Andrea Gregori

    2010-06-30

    We investigate the physics of black holes in the light of the quantum theoretical framework proposed in [1]. It is argued that black holes are completely non-local objects, and that the only one which really exists is the universe itself.

  8. Hadrons As Kerr-Newman Black Holes

    E-Print Network [OSTI]

    R. L. Oldershaw

    2010-03-15

    The scale invariance of the source-free Einstein field equations suggests that one might be able to model hadrons as "strong gravity" black holes, if one uses an appropriate rescaling of units or a revised gravitational coupling factor. The inner consistency of this hypothesis is tested by retrodicting a close approximation to the mass of the proton from an equation that relates the angular momentum and mass of a Kerr black hole. More accurate mass and radius values for the proton are then retrodicted using the geometrodynamics form of the full Kerr-Newman solution of the Einstein-Maxwell equations. The radius of an alpha particle is calculated as an additional retrodictive test. In a third retrodictive test of the "strong gravity" hypothesis, the subatomic particle mass spectrum in the 100 MeV to 7,000 MeV range is retrodicted to a first approximation using the Kerr solution of General Relativity. The particle masses appear to form a restricted set of quantized values of the Kerr solution: n^1/2 M, where values of n are a set of discrete integers and M is the revised Planck mass. The accuracy of the 27 retrodicted masses averages 98.4%. Finally, the new atomic scale gravitational coupling constant suggests a radical revision of the assumptions governing the Planck scale, and leads to a natural explanation for the fine structure constant.

  9. Probing the puncture for black hole simulations

    E-Print Network [OSTI]

    J. David Brown

    2009-10-23

    With the puncture method for black hole simulations, the second infinity of a wormhole geometry is compactified to a single "puncture point" on the computational grid. The region surrounding the puncture quickly evolves to a trumpet geometry. The computational grid covers only a portion of the trumpet throat. It ends at a boundary whose location depends on resolution. This raises the possibility that perturbations in the trumpet geometry could propagate down the trumpet throat, reflect from the puncture boundary, and return to the black hole exterior with a resolution--dependent time delay. Such pathological behavior is not observed. This is explained by the observation that some perturbative modes propagate in the conformal geometry, others propagate in the physical geometry. The puncture boundary exists only in the physical geometry. The modes that propagate in the physical geometry are always directed away from the computational domain at the puncture boundary. The finite difference stencils ensure that these modes are advected through the boundary with no coupling to the modes that propagate in the conformal geometry. These results are supported by numerical experiments with a code that evolves spherically symmetric gravitational fields with standard Cartesian finite difference stencils. The code uses the Baumgarte--Shapiro--Shibata--Nakamura formulation of Einstein's equations with 1+log slicing and gamma--driver shift conditions.

  10. BLACK HOLE FORAGING: FEEDBACK DRIVES FEEDING

    SciTech Connect (OSTI)

    Dehnen, Walter; King, Andrew, E-mail: wd11@leicester.ac.uk, E-mail: ark@astro.le.ac.uk [Theoretical Astrophysics Group, University of Leicester, Leicester LE1 7RH (United Kingdom)] [Theoretical Astrophysics Group, University of Leicester, Leicester LE1 7RH (United Kingdom)

    2013-11-10

    We suggest a new picture of supermassive black hole (SMBH) growth in galaxy centers. Momentum-driven feedback from an accreting hole gives significant orbital energy, but little angular momentum to the surrounding gas. Once central accretion drops, the feedback weakens and swept-up gas falls back toward the SMBH on near-parabolic orbits. These intersect near the black hole with partially opposed specific angular momenta, causing further infall and ultimately the formation of a small-scale accretion disk. The feeding rates into the disk typically exceed Eddington by factors of a few, growing the hole on the Salpeter timescale and stimulating further feedback. Natural consequences of this picture include (1) the formation and maintenance of a roughly toroidal distribution of obscuring matter near the hole; (2) random orientations of successive accretion disk episodes; (3) the possibility of rapid SMBH growth; (4) tidal disruption of stars and close binaries formed from infalling gas, resulting in visible flares and ejection of hypervelocity stars; (5) super-solar abundances of the matter accreting on to the SMBH; and (6) a lower central dark-matter density, and hence annihilation signal, than adiabatic SMBH growth implies. We also suggest a simple subgrid recipe for implementing this process in numerical simulations.

  11. Extremal Limits of Rotating Black Holes

    E-Print Network [OSTI]

    Laura Andrianopoli; Riccardo D'Auria; Antonio Gallerati; Mario Trigiante

    2013-05-30

    We consider non-extremal, stationary, axion-dilaton solutions to ungauged symmetric supergravity models, obtained by Harrison transformations of the non-extremal Kerr solution. We define a general algebraic procedure, which can be viewed as an Inonu-Wigner contraction of the Noether charge matrix associated with the effective D=3 sigma-model description of the solution, yielding, through different singular limits, the known BPS and non-BPS extremal black holes (which include the under-rotating non-BPS one). The non-extremal black hole can thus be thought of as "interpolating" among these limit-solutions. The algebraic procedure that we define generalizes the known Rasheed-Larsen limit which yielded, in the Kaluza-Klein theory, the first instance of under-rotating extremal solution. As an example of our general result, we discuss in detail the non-extremal solution in the T^3-model, with either (q_0, p^1) or (p^0, q_1) charges switched on, and its singular limits. Such solutions, computed in D=3 through the solution-generating technique, is completely described in terms of D=4 fields, which include the fully integrated vector fields.

  12. Quasinormal modes of test fields around regular black holes

    E-Print Network [OSTI]

    Bobir Toshmatov; Ahmadjon Abdujabbarov; Zden?k Stuchlík; Bobomurat Ahmedov

    2015-04-25

    We study scalar, electromagnetic and gravitational test fields in the Hayward, Bardeen and Ay\\'on-Beato-Garc\\'ia regular black hole spacetimes and demonstrate that the test fields are stable in all these spacetimes. Using the sixth order WKB approximation of the linear "axial" perturbative scheme, we determine dependence of the quasinormal mode (QNM) frequencies on the characteristic parameters of the test fields and the spacetime charge parameters of the regular black holes. We give also the greybody factors, namely the transmission and reflection coefficients of scattered scalar, electromagnetic and gravitational waves. We show that damping of the QNMs in regular black hole spacetimes is suppressed in comparison to the case of Schwarzschild black holes, and increasing charge parameter of the regular black holes increases reflection and decreases transmission factor of incident waves for each of the test fields.

  13. Hypervelocity binary stars: smoking gun of massive binary black holes

    E-Print Network [OSTI]

    Youjun Lu; Qingjuan Yu; D. N. C. Lin

    2007-07-22

    The hypervelocity stars recently found in the Galactic halo are expelled from the Galactic center through interactions between binary stars and the central massive black hole or between single stars and a hypothetical massive binary black hole. In this paper, we demonstrate that binary stars can be ejected out of the Galactic center with velocities up to 10^3 km/s, while preserving their integrity, through interactions with a massive binary black hole. Binary stars are unlikely to attain such high velocities via scattering by a single massive black hole or through any other mechanisms. Based on the above theoretical prediction, we propose a search for binary systems among the hypervelocity stars. Discovery of hypervelocity binary stars, even one, is a definitive evidence of the existence of a massive binary black hole in the Galactic center.

  14. Weighing Black Holes in high-z SCUBA Galaxies

    E-Print Network [OSTI]

    Alexander, D M

    2006-01-01

    Deep SCUBA surveys have uncovered a population of dust-enshrouded star-forming galaxies at z~2. Using the ultra-deep 2 Ms Chandra Deep Field-North survey we recently showed that a large fraction of these systems are also undergoing intense black-hole growth. Here we provide further constraints on the properties of the black holes in SCUBA galaxies using the virial black-hole mass estimator. We show that typical SCUBA galaxies are likely to host black holes with M_BH~10^7-10^8 M_solar which are accreting at, or close to, the Eddington limit. These results provide qualitative support for our earlier conclusion that the growth of the black hole lags that of the host galaxy in these massive ultraluminous galaxies.

  15. Confounding variables and Simpson's paradox SCI 199Y A particularly intriguing type of confounding occurs when a confounding variable, once exposed,

    E-Print Network [OSTI]

    Reid, Nancy

    -seventies, the tax rate in the United States was lowered for every category of income. However, people's income of the death penalty is about the same rate for white and black defendants, in fact, slightly higher for white applied to; it is hidden in a comparison of the overall admission rates. Here is another example, from

  16. Black hole entropy predictions without Immirzi parameter and Hawking radiation of single-partition black hole

    E-Print Network [OSTI]

    Brian Kong; Youngsub Yoon

    2015-04-14

    By pointing out an error in the previous derivation of the area spectrum based on Ashtekar's variables, we suggest a new area spectrum; in the previous derivation of the area spectrum, area operator is expressed in terms of Levi-Civita symbol instead of Levi-Civita tensor, which should have been used. At first glance, this consideration may not seem to make any difference in the actual area spectrum, but upon quantization it yields a difference, as classical equivalence doesn't always imply quantum equivalence. For this purpose, we construct our "newer" variables. In particular, our "newer" variables are mathematically consistent; the constraint algebra is closed. Moreover, by using our new area spectrum, we "almost correctly" predict the Bekenstein-Hawking entropy without adjusting Immirzi parameter; we show that a numerical formula actually turned out to be $0.997\\cdots$ which is very close to 1, the expected value with the black hole entropy given as $A/4$. We conjecture that the difference, 0.003, is due to the extra dimensions which may modify the area spectrum. Then, we derive a formula for the degeneracy for a single-partition black hole, (i.e. black hole made out of single unit area) and explicitly show that our area spectrum correctly reproduces the degeneracy. Furthermore, by two totally different methods, we obtain the proportionality constant "$C$" related to the degeneracy. The first method based on fitting yields 172$\\sim$173, while the second method yields 172.87$\\cdots$, which strongly suggest that our area spectrum is on the right track. We also show that the area spectrums based on Ashtekar variables neither reproduces the degeneracy of single-partition black hole nor yields the agreement for $C$ obtained by the two methods.

  17. Charged black holes in generalized teleparallel gravity

    SciTech Connect (OSTI)

    Rodrigues, M.E.; Houndjo, M.J.S.; Tossa, J.; Momeni, D.; Myrzakulov, R. E-mail: sthoundjo@yahoo.fr E-mail: d.momeni@yahoo.com

    2013-11-01

    In this paper we investigate charged static black holes in 4D for generalized teleparallel models of gravity, based on torsion as the geometric object for describing gravity according to the equivalence principle. As a motivated idea, we introduce a set of non-diagonal tetrads and derive the full system of non linear differential equations. We prove that the common Schwarzschild gauge is applicable only when we study linear f(T) case. We reobtain the Reissner-Nordstrom-de Sitter (or RN-AdS) solution for the linear case of f(T) and perform a parametric cosmological reconstruction for two nonlinear models. We also study in detail a type of the no-go theorem in the framework of this modified teleparallel gravity.

  18. Bubbling the Newly Grown Black Ring Hair

    E-Print Network [OSTI]

    Vasilakis, Orestis

    2012-01-01

    New families of BPS black ring solutions with four electric and four dipole magnetic charges have recently been explicitly constructed and uplifted to M-theory. These solutions were found to belong to a CFT with central charge different compared to the one of the STU model. Because of their importance to AdS/CFT, here we give the microstate description of these geometries in terms of topological bubbles and supertubes. The fourth charge results in an additional flux through the topological cycles that resolve the brane singularities. The analog of these solutions in the IIB frame yield a generalized regular supertube with three electric charges and one dipole charge. Direct comparison is also made with the previously-known bubbled geometries.

  19. Bubbling the Newly Grown Black Ring Hair

    E-Print Network [OSTI]

    Orestis Vasilakis

    2012-02-08

    New families of BPS black ring solutions with four electric and four dipole magnetic charges have recently been explicitly constructed and uplifted to M-theory. These solutions were found to belong to a CFT with central charge different compared to the one of the STU model. Because of their importance to AdS/CFT, here we give the microstate description of these geometries in terms of topological bubbles and supertubes. The fourth charge results in an additional flux through the topological cycles that resolve the brane singularities. The analog of these solutions in the IIB frame yield a generalized regular supertube with three electric charges and one dipole charge. Direct comparison is also made with the previously-known bubbled geometries.

  20. Black hole thermodynamics in finite time

    E-Print Network [OSTI]

    Gruber, Christine

    2016-01-01

    Finite-time thermodynamics provides the means to revisit ideal thermodynamic equilibrium processes in the light of reality and investigate the energetic "price of haste", i.e. the consequences of carrying out a process in finite time, when perfect equilibrium cannot be awaited due to economic reasons or the nature of the process. Employing the formalism of geometric thermodynamics, a lower bound on the energy dissipated during a process is derived from the thermodynamic length of that process. The notion of length is hereby defined via a metric structure on the space of equilibrium thermodynamics, spanned by a set of thermodynamic variables describing the system. Since the aim of finite-time thermodynamics is to obtain realistic limitations on idealized scenarios, it is a useful tool to reassess the efficiency of thermodynamic processes. We examine its implications for black hole thermodynamics, in particular scenarios inspired by the Penrose process, a thought experiment by which work can be extracted from a...

  1. Collisions with Black Holes and Deconfined Plasmas

    E-Print Network [OSTI]

    Amsel, Aaron J; Virmani, Amitabh

    2008-01-01

    We use AdS/CFT to investigate i) high energy collisions with balls of deconfined plasma surrounded by a confining phase and ii) the rapid localized heating of a deconfined plasma. Both of these processes are dual to collisions with black holes, where they result in the nucleation of a new "arm" of the horizon reaching out in the direction of the incident object. We study the resulting non-equilibrium dynamics in a universal limit of the gravitational physics which may indicate universal behavior of deconfined plasmas at large N_c. Process (i) produces "virtual" arms of the plasma ball, while process (ii) can nucleate surprisingly large bubbles of a higher temperature phase.

  2. Collisions with Black Holes and Deconfined Plasmas

    E-Print Network [OSTI]

    Aaron J. Amsel; Donald Marolf; Amitabh Virmani

    2007-12-13

    We use AdS/CFT to investigate i) high energy collisions with balls of deconfined plasma surrounded by a confining phase and ii) the rapid localized heating of a deconfined plasma. Both of these processes are dual to collisions with black holes, where they result in the nucleation of a new "arm" of the horizon reaching out in the direction of the incident object. We study the resulting non-equilibrium dynamics in a universal limit of the gravitational physics which may indicate universal behavior of deconfined plasmas at large N_c. Process (i) produces "virtual" arms of the plasma ball, while process (ii) can nucleate surprisingly large bubbles of a higher temperature phase.

  3. Thermodynamic Product Formula for Ho?ava Lifshitz Black Hole

    E-Print Network [OSTI]

    Parthapratim Pradhan

    2015-06-10

    We examine the thermodynamic properties of inner and outer horizons in the background of Ho\\v{r}ava Lifshitz black hole. We compute the \\emph{horizon radii product, the surface area product, the entropy product, the surface temperature product, the Komar energy product and the specific heat product} for both the horizons of said black hole. We show that surface area product, entropy product and irreducible mass product are \\emph{universal} quantities, whereas the surface temperature product, Komar energy product and specific heat product are \\emph{not universal} quantities because they all are depends on mass parameter. We also observe that the \\emph{First law} of black hole thermodynamics and \\emph {Smarr-Gibbs-Duhem } relations do not hold for this black hole. The underlying reason behind this failure due to the scale invariance of the coupling constant. We further derive the \\emph{Smarr mass formula} and \\emph{Christodolou-Ruffini mass formula} for such black hole spacetime. Moreover we study the stability of such black hole by computing the specific heat for both the horizons. It has been observed that under certain condition the black hole possesses second order phase transition.

  4. Varying fine structure 'constant' and charged black holes

    SciTech Connect (OSTI)

    Bekenstein, Jacob D.; Schiffer, Marcelo

    2009-12-15

    Speculation that the fine-structure constant {alpha} varies in spacetime has a long history. We derive, in 4-D general relativity and in isotropic coordinates, the solution for a charged spherical black hole according to the framework for dynamical {alpha} J. D. Bekenstein, Phys. Rev. D 25, 1527 (1982).. This solution coincides with a previously known one-parameter extension of the dilatonic black hole family. Among the notable properties of varying-{alpha} charged black holes are adherence to a 'no hair' principle, the absence of the inner (Cauchy) horizon of the Reissner-Nordstroem black holes, the nonexistence of precisely extremal black holes, and the appearance of naked singularities in an analytic extension of the relevant metric. The exteriors of almost extremal electrically (magnetically) charged black holes have simple structures which makes their influence on applied magnetic (electric) fields transparent. We rederive the thermodynamic functions of the modified black holes; the otherwise difficult calculation of the electric potential is done by a shortcut. We confirm that variability of {alpha} in the wake of expansion of the universe does not threaten the generalized second law.

  5. The Evolution of Accreting Black Holes in Outburst

    E-Print Network [OSTI]

    John A. Tomsick

    2004-01-12

    Black hole binaries exhibit dramatic changes in their X-ray spectral and timing properties over time, providing important clues about the physical processes that occur in these systems. Black holes and black hole candidates are prime targets for RXTE with observational goals including the study of extreme gravitational fields and jet formation mechanisms. The great wealth of data from RXTE has helped us to learn about these systems as well as raising new questions about accreting black holes. RXTE observations have allowed us to study a wide range of black hole science topics including the connection between the accretion disk and jets, the geometry of the inner accretion flow, and the physical changes that occur between spectral states. In this presentation, I discuss significant results on these topics that have been obtained for persistent and transient black holes over the past several years, and I present results from our program of X-ray and radio observations during the decays of black hole transient outbursts.

  6. Hybrid method for understanding black-hole mergers: Inspiralling case

    E-Print Network [OSTI]

    David A. Nichols; Yanbei Chen

    2012-02-21

    We adapt a method of matching post-Newtonian and black-hole-perturbation theories on a timelike surface (which proved useful for understanding head-on black-hole-binary collisions) to treat equal-mass, inspiralling black-hole binaries. We first introduce a radiation-reaction potential into this method, and we show that it leads to a self-consistent set of equations that describe the simultaneous evolution of the waveform and of the timelike matching surface. This allows us to produce a full inspiral-merger-ringdown waveform of the l=2, m=2,-2 modes of the gravitational waveform of an equal-mass black-hole-binary inspiral. These modes match those of numerical-relativity simulations well in phase, though less well in amplitude for the inspiral. As a second application of this method, we study a merger of black holes with spins antialigned in the orbital plane (the "superkick" configuration). During the ringdown of the superkick, the phases of the mass- and current-quadrupole radiation become locked together, because they evolve at the same quasinormal mode frequencies. We argue that this locking begins during merger, and we show that if the spins of the black holes evolve via geodetic precession in the perturbed black-hole spacetime of our model, then the spins precess at the orbital frequency during merger. In turn, this gives rise to the correct behavior of the radiation, and produces a kick similar to that observed in numerical simulations.

  7. Stability of black holes based on horizon thermodynamics

    E-Print Network [OSTI]

    Meng-Sen Ma; Ren Zhao

    2015-11-11

    On the basis of horizon thermodynamics we study the thermodynamic stability of black holes constructed in general relativity and Gauss-Bonnet gravity. In the framework of horizon thermodynamics there are only five thermodynamic variables $E,P,V,T,S$. It is not necessary to consider concrete matter fields, which may contribute to the pressure of black hole thermodynamic system. In non-vacuum cases, we can derive the equation of state, $P=P(V,T)$. According to the requirements of stable equilibrium in conventional thermodynamics, we start from these thermodynamic variables to calculate the heat capacity at constant pressure and Gibbs free energy and analyze the local and global thermodynamic stability of black holes. It is shown that $P>0$ is the necessary condition for black holes in general relativity to be thermodynamically stable, however this condition cannot be satisfied by many black holes in general relativity. For black hole in Gauss-Bonnet gravity negative pressure can be feasible, but only local stable black hole exists in this case.

  8. Higgs Boson Production from Black Holes at the LHC

    E-Print Network [OSTI]

    Gouranga C. Nayak; J. Smith

    2006-06-09

    If the fundamental Planck scale is near a TeV, then TeV scale black holes should be produced in proton-proton collisions at the LHC where \\sqrt{s} = 14 TeV. As the temperature of the black holes can be ~ 1 TeV we also expect production of Higgs bosons from them via Hawking radiation. This is a different production mode for the Higgs boson, which would normally be produced via direct pQCD parton fusion processes. In this paper we compare total cross sections and transverse momentum distributions d\\sigma/dp_T for Higgs production from black holes at the LHC with those from direct parton fusion processes at next-to-next-to-leading order and next-to-leading order respectively. We find that the Higgs production from black holes can be larger or smaller than the direct pQCD production depending upon the Planck mass and black hole mass. We also find that d\\sigma/dp_T of Higgs production from black holes increases as a function of p_T which is in sharp contrast with the pQCD predictions where d\\sigma/dp_T decreases so we suggest that the measurement of an increase in d\\sigma/dp_T as p_T increases for Higgs (or any other heavy particle) production can be a useful signature for black holes at the LHC.

  9. Master of Science in Engineering and Technology Management Louisiana Tech University Six Sigma Black Belt Certification

    E-Print Network [OSTI]

    Selmic, Sandra

    Black Belt Certification A Louisiana Tech University Six Sigma Black Belt certification can be obtained, STAT 507 Design and Analysis of Experiments, and INEN 557 Six Sigma Black Belt Project with a B the Louisiana Tech University Six Sigma Black Belt certification. INEN 514 is offered in the fall and spring

  10. Black Hole Thermodynamic Products in Einstein Gauss Bonnet Gravity

    E-Print Network [OSTI]

    Mandal, Abhijit

    2015-01-01

    We study the thermodynamic properties of black hole horizons in Einstein Gauss Bonnet gravity. We derive the thermodynamic products of characteristic parameters to mark which are global. We further interpret the stability of the black holes by computing the specific heat for both horizons. Stable and unstable phases of horizons are pointed out. The phase transitions with respect to the charge in nature of specific heat are also observed. All these calculation might be helpful to understand the microscopic nature of such black holes.

  11. Inferring black hole charge from backscattered electromagnetic radiation

    E-Print Network [OSTI]

    Luís C. B. Crispino; Sam R. Dolan; Atsushi Higuchi; Ednilton S. de Oliveira

    2014-09-16

    We compute the scattering cross section of Reissner-Nordstr\\"om black holes for the case of an incident electromagnetic wave. We describe how scattering is affected by both the conversion of electromagnetic to gravitational radiation, and the parity-dependence of phase shifts induced by the black hole charge. The latter effect creates a helicity-reversed scattering amplitude that is non-zero in the backward direction. We show that from the character of the electromagnetic wave scattered in the backward direction it is possible, in principle, to infer if a static black hole is charged.

  12. Back reaction on a Reissner-Nordstro''m black hole

    SciTech Connect (OSTI)

    Wang, Bobo; Huang, Chao-guang

    2001-06-15

    The perturbed (''dressed'') metric of the conformally invariant scalar field in a Reissner-Nordstroem (RN) black hole is given by solving the semiclassical Einstein and Maxwell equations according to York's back-reaction approach. Some properties of the ''dressed'' black hole are obtained, such as its ''dressed'' mass, the location of the event horizon, and its surface gravity. It will also be found that the hypersurfaces of r{sub +} and r{sub {minus}} which are the event and Cauchy horizons in the ''naked'' RN black hole, become spacelike in the perturbed geometry.

  13. A Nonsingular Brans Wormhole: An Analogue to Naked Black Holes

    E-Print Network [OSTI]

    Amrita Bhattacharya; Ramil Izmailov; Ettore Laserra; Kamal K. Nandi

    2011-07-28

    In a recent paper, we showed the Jordan frame vacuum Brans Class I solution provided a wormhole analogue to Horowitz-Ross naked black hole in the wormhole range -3/2naked black holes, as described by Horowitz and Ross, are spacetimes where the tidal forces attain their maxima above the black hole horizon. We show that in the non-singular Class II spacetime this maxima is attained above the throat and thus can be treated as a wormhole analogue. Some related issues are also addressed.

  14. From Special Geometry to Black Hole Partition Functions

    E-Print Network [OSTI]

    Thomas Mohaupt

    2008-12-22

    These notes are based on lectures given at the Erwin-Schrodinger Insitut in Vienna in 2006/07 and at the 2007 School on Attractor Mechanism in Frascati. Lecture I: special geometry from the superconformal point of view. Lecture II: black hole attractor mechanism, its underlying variational principle, and black hole partition functions. Lecture III: large and small BPS black holes in N=4 supergravity. Lecture IV: state counting for N=4 string compactifications. Appendix A: special geometry from the mathematical point of view. Appendix B: review of modular forms. Contains four problems which allow the readers to develop some of the key concepts by themselves.

  15. Safeguards Approaches for Black Box Processes or Facilities

    SciTech Connect (OSTI)

    Diaz-Marcano, Helly; Gitau, Ernest TN; Hockert, John; Miller, Erin; Wylie, Joann

    2013-09-25

    The objective of this study is to determine whether a safeguards approach can be developed for “black box” processes or facilities. These are facilities where a State or operator may limit IAEA access to specific processes or portions of a facility; in other cases, the IAEA may be prohibited access to the entire facility. The determination of whether a black box process or facility is safeguardable is dependent upon the details of the process type, design, and layout; the specific limitations on inspector access; and the restrictions placed upon the design information that can be provided to the IAEA. This analysis identified the necessary conditions for safeguardability of black box processes and facilities.

  16. Static Charged Black Hole Solutions in Horava-Lifshitz Gravity

    E-Print Network [OSTI]

    Jin-Zhang Tang

    2010-01-12

    In the present work, we search static charged black hole solutions to Ho\\v{r}ava-Lifshitz gravity with or without projectability condition. We consider the most general form of action which electromagnetic field couples with Ho\\v{r}ava-Lifshitz gravity. With the projectability condition, we find dS-Reissner-Nordstrom black hole solution in Painlev\\'e-Gullstrand type coordinates in the IR region and a de-Sitter space-time solution in the UV region. Without the projectability condition, in the IR region, we find an especial static charged black hole solution.

  17. The r-Process in Black Hole Winds

    E-Print Network [OSTI]

    Shinya Wanajo; Hans-Thomas Janka

    2010-06-11

    All the current r-process scenarios relevant to core-collapse supernovae are facing severe difficulties. In particular, recent core-collapse simulations with neutrino transport show no sign of a neutron-rich wind from the proto-neutron star. In this paper, we discuss nucleosynthesis of the r-process in an alternative astrophysical site, "black hole winds", which are the neutrino-driven outflow from the accretion torus around a black hole. This condition is assumed to be realized in double neutron star mergers, neutron star - black hole mergers, or hypernovae.

  18. Scalar emission in a rotating Gödel black hole

    E-Print Network [OSTI]

    Songbai Chen; Bin Wang; Jiliang Jing

    2008-08-23

    We study the absorption probability and Hawking radiation of the scalar field in the rotating G\\"{o}del black hole in minimal five-dimensional gauged supergravity. We find that G\\"{o}del parameter $j$ imprints in the greybody factor and Hawking radiation. It plays a different role from the angular momentum of the black hole in the Hawking radiation and super-radiance. These information can help us know more about rotating G\\"{o}del black holes in minimal five-dimensional gauged supergravity.

  19. Little Black Holes:Dark Matter And Ball Lightning

    E-Print Network [OSTI]

    Mario Rabinowitz

    2002-12-11

    Small,quiescent black holes can be considered as candidates for the missing dark matter of the universe,and as the core energy source of ball lightning.By means of gravitational tunneling,directed radiation is emitted from black holes in a process much attenuated from that of Hawking radiation,P SH, which has proven elusive to detect.Gravitational tunneling emission is similar to electric field emission of electronsfrom a metal in that a second body is involved which lowers the barrier and gives the barrier a finite rather than infinite width.Hawking deals with a single isolated black hole.

  20. Recent Progresses Of Accretion Disk Models Around Black Holes

    E-Print Network [OSTI]

    Sandip K. Chakrabarti

    1997-03-09

    Accretion disk models have evolved from Bondi flows in the 1950s to Keplerian disks in the 1970s and finally to advective transonic flows in the 1990s. We discuss recent progresses in this subject and show that sub-Keplerian flows play a major role in determining the spectral properties of black holes. Centrifugal pressure supported enhanced density region outside the black hole horizon produces hard X-rays and gamma rays by reprocessing intercepted soft photons emitted by the Keplerian disk terminated farther out from the black holes. Quasi-periodic oscillations can also be understood from the dynamic or thermal resonance effects of the enhanced density region.

  1. Proceedings of the black liquor research program review fourth meeting held July 28--30, 1987

    SciTech Connect (OSTI)

    Emerson, D. B.; Whitworth, B. A.

    1987-10-01

    Research programs, presented at the black liquor review meeting are described. Research topics include the following: Cooperative Program in Kraft Recovery; Black Liquor Physical Properties; Viscosity of Strong Black Liquor; Ultrafiltration of Kraft Black Liquor; Molecular Weight Distribution of Kraft Lignin; Black Liquor Droplet Formation Project; Fundamental Studies of Black Liquor Combustion; Black Liquor Combustion Sensors; Flash X-ray Imagining of Black Liquor Sprays; Laser Induced Fluorescence For Process Control In The Pulp and Paper Industry; Recovery Boiler Optimization; Black Liquor Gasification and Use of the Products in Combined-Cycle Cogeneration; Black Liquor Steam Plasma Automization; The B and W Pyrosonic 2000R System; Monsteras Boiler Control System; and Cooperative Program Project Reviews. Individual projects are processed separately for the data bases.

  2. The Quantum Black Hole Specific Heat is Positive

    E-Print Network [OSTI]

    Andrzej Z. Gorski; Pawel O. Mazur

    1997-05-16

    We suggest in this Letter that the Bekenstein-Hawking black hole entropy accounts for the degrees of freedom which are excited at low temperatures only and hence it leads to the negative specific heat. Taking into account the physical degrees of freedom which are excited at high temperatures, the existence of which we postulate, we compute the total specific heat of the quantum black hole that appears to be positive. This is done in analogy to the Planck's treatment of the black body radiation problem. Other thermodynamic functions are computed as well. Our results and the success of the thermodynamic description of the quantum black hole suggest an underlying atomic (discrete) structure of gravitation. The basic properties of these gravitational atoms are found.

  3. Giant black hole ringings induced by massive gravity

    E-Print Network [OSTI]

    Yves Decanini; Antoine Folacci; Mohamed Ould El Hadj

    2014-01-01

    A distorted black hole radiates gravitational waves in order to settle down in one of the geometries permitted by the no-hair theorem. During that relaxation phase, a characteristic damped ringing is generated. It can be theoretically constructed from the black hole quasinormal frequencies (which govern its oscillating behavior and its decay) and from the associated excitation factors (which determine intrinsically its amplitude) by carefully taking into account the source of the distortion. Here, by considering the Schwarzschild black hole in the framework of massive gravity, we show that the excitation factors have an unexpected strong resonant behavior leading to giant ringings which are, moreover, slowly decaying. Such extraordinary black hole ringings could be observed by the next generations of gravitational wave detectors and allow us to test the various massive gravity theories or their absence could be used to impose strong constraints on the graviton mass.

  4. Black Holes in Gauss-Bonnet Gravity's Rainbow

    E-Print Network [OSTI]

    Seyed Hossein Hendi; Mir Faizal

    2015-08-08

    In this paper, we will generalize the Gauss-Bonnet gravity to an energy dependent Gauss-Bonnet theory of gravity, which we shall call as the Gauss-Bonnet gravity's rainbow. We will also couple this theory to a Maxwell's theory. We will analyze black hole solutions in this energy dependent Gauss-Bonnet gravity's rainbow. We will calculate the modifications to the thermodynamics of black holes in the Gauss-Bonnet's gravity's rainbow. We will demonstrate that even though the thermodynamics of the black holes get modified in the Gauss-Bonnet gravity's rainbow, the first law of thermodynamics still holds for this modified thermodynamics. We will also comment on the thermal stability of the black hole solutions in this theory.

  5. Black Liquor Gasification Process Review and Status Update 

    E-Print Network [OSTI]

    Brown, C.

    1993-01-01

    After more than two decades of research and development, black liquor gasification is poised to become a commercial reality in the 90's. Several promising developments are underway in North America and Europe. In fact, all major recovery boiler...

  6. Black hole physics: recent developments and observational perspectives

    E-Print Network [OSTI]

    Gourgoulhon, Eric

    on a black hole: up to 42% of the mass-energy mc2 of accreted matter ! NB: thermonuclear reactions release: a very deep gravitational potential well Release of potential gravitational energy by accretion

  7. Black holes and tests of gravitation Eric Gourgoulhon

    E-Print Network [OSTI]

    Gourgoulhon, Eric

    potential well Release of potential gravitational energy by accretion on a black hole: up to 42% of the mass-energy mc2 of accreted matter ! NB: thermonuclear reactions release less than 1% mc2 Matter falling

  8. Black hole evaporation in a noncommutative charged Vaidya model

    SciTech Connect (OSTI)

    Sharif, M. Javed, W.

    2012-06-15

    We study the black hole evaporation and Hawking radiation for a noncommutative charged Vaidya black hole. For this purpose, we determine a spherically symmetric charged Vaidya model and then formulate a noncommutative Reissner-Nordstroem-like solution of this model, which leads to an exact (t - r)-dependent metric. The behavior of the temporal component of this metric and the corresponding Hawking temperature are investigated. The results are shown in the form of graphs. Further, we examine the tunneling process of charged massive particles through the quantum horizon. We find that the tunneling amplitude is modified due to noncommutativity. Also, it turns out that the black hole evaporates completely in the limits of large time and horizon radius. The effect of charge is to reduce the temperature from a maximum value to zero. We note that the final stage of black hole evaporation is a naked singularity.

  9. Black-Body Radiation Of Noncommutative Gauge Fields

    E-Print Network [OSTI]

    A. H. Fatollahi; M. Hajirahimi

    2006-11-21

    The black-body radiation is considered in a theory with noncommutative electromagnetic fields; that is noncommutativity is introduced in field space, rather than in real space. A direct implication of the result on Cosmic Microwave Background map is argued.

  10. Ukraine's Military Role in the Black Sea Region 

    E-Print Network [OSTI]

    Coffman, Amy Beth; Crump, James Andrew; Dickson, Robbi K.; Mueller, Meaghan; Pulis, Sarah L.

    2010-01-01

    Only Ukraine's civilian and military leadership can determine the best course of action Ukraine should undertake to secure the Black Sea region (BSR). By analyzing Ukraine's precarious security environment and assessing the current security...

  11. In Celebration of Black History Month, Energy Secretary Moniz...

    Office of Environmental Management (EM)

    Art of Science February 23, 2015 - 1:50am Addthis News Media Contact 202 586 4940 RSVP@hq.doe.gov In Celebration of Black History Month, Energy Secretary Moniz and Director of the...

  12. MLK Day/Black History Month DOE Celebration

    Broader source: Energy.gov [DOE]

    Join us as the Department honors both Dr. King and Black History Month with a dialogue on the history of civil rights for all. Secretary Ernest Moniz will open our program.

  13. Tensile Strength and the Mining of Black Holes

    E-Print Network [OSTI]

    Adam R. Brown

    2012-07-13

    There are a number of important thought experiments that involve raising and lowering boxes full of radiation in the vicinity of black hole horizons. This paper looks at the limitations placed on these thought experiments by the null energy condition, which imposes a fundamental bound on the tensile-strength-to-weight ratio of the materials involved, makes it impossible to build a box near the horizon that is wider than a single wavelength of the Hawking quanta and puts a severe constraint on the operation of 'space elevators' near black holes. In particular, it is shown that proposals for mining black holes by lowering boxes near the horizon, collecting some Hawking radiation and dragging it out to infinity cannot proceed nearly as rapidly as has previously been claimed and that as a consequence of this limitation the boxes and all the moving parts are superfluous and black holes can be destroyed equally rapidly by threading the horizon with strings.

  14. Physiological responses of a black spruce forest to weather

    E-Print Network [OSTI]

    1997-01-01

    a black spruce forest to weather Michael L. Goulden, • Bruceresponses of the forest to weather. The annual rates ofgross forest CO 2 exchange to weather is required before the

  15. Ecology of Wintering Black-capped Vireos in Mexico 

    E-Print Network [OSTI]

    Powell, Robert Andrew

    2013-11-06

    The black-capped vireo (Vireo atricapilla) is an endangered Neotropical migratory songbird that has received considerable attention in its breeding range, but relatively little attention in its winter range in Mexico. To ...

  16. Circumnuclear Media and Accretion Rates of Quiescent Supermassive Black Holes

    E-Print Network [OSTI]

    Generozov, Aleksey; Metzger, Brian D

    2015-01-01

    We calculate steady-state, one-dimensional hydrodynamic profiles of hot gas in slowly accreting ("quiescent") galactic nuclei for a range of central black hole masses, parameterized gas heating rates, and observationally-motivated stellar density profiles. Mass is supplied to the circumnuclear medium by stellar winds, while energy is injected primarily by stellar winds, supernovae, and black hole feedback. Analytic estimates are derived for the stagnation radius (where the radial velocity of the gas passes through zero) and the black hole accretion rate, as a function of the black hole mass and the gas heating efficiency, the latter being related to the star-formation history. We assess the conditions under which radiative instabilities develop in the hydrostatic region near the stagnation radius, both in the case of a single burst of star formation and for the average star formation history predicted by cosmological simulations. By combining a sample of measured nuclear X-ray luminosities from nearby quiesce...

  17. Magnetic wormholes and black universes with invisible ghosts

    E-Print Network [OSTI]

    Bronnikov, K A

    2015-01-01

    We construct explicit examples of globally regular static, spherically symmetric solutions in general relativity with scalar and electromagnetic fields describing traversable wormholes with flat and AdS asymptotics and regular black holes, in particular, black universes. (A black universe is a regular black hole with an expanding, asymptotically isotropic space-time beyond the horizon.) The existence of such objects requires invoking scalars with negative kinetic energy ("phantoms", or "ghosts"), which are not observed under usual physical conditions. To account for that, the so-called "trapped ghosts" were previously introduced, i.e., scalars whose kinetic energy is only negative in a restricted strong-field region of space-time and positive outside it. This approach leads to certain problems, including instability (as is illustrated here by derivation of an effective potential for spherical pertubations of such systems). In this paper, we use for model construction what we call "invisible ghosts", i.e., pha...

  18. Improvements to the construction of binary black hole initial data

    E-Print Network [OSTI]

    Serguei Ossokine; Francois Foucart; Harald P. Pfeiffer; Michael Boyle; Béla Szilágyi

    2015-06-04

    Construction of binary black hole initial data is a prerequisite for numerical evolutions of binary black holes. This paper reports improvements to the binary black hole initial data solver in the Spectral Einstein Code, to allow robust construction of initial data for mass-ratio above 10:1, and for dimensionless black hole spins above 0.9, while improving efficiency for lower mass-ratios and spins. We implement a more flexible domain decomposition, adaptive mesh refinement and an updated method for choosing free parameters. We also introduce a new method to control and eliminate residual linear momentum in initial data for precessing systems, and demonstrate that it eliminates gravitational mode mixing during the evolution. Finally, the new code is applied to construct initial data for hyperbolic scattering and for binaries with very small separation.

  19. Black Image in Cinema and Theatre in America

    E-Print Network [OSTI]

    Williams, Grayling

    1983-01-01

    BLACK IMAGE IN CINEMA AND THEATRE IN AMERICA* By GraylingIN THE AFRICAN-AMERICAN CINEMA Given the lack of informationa Negro's Ambition (1916). The cinema therefore provided the

  20. The Energy for 2+1 Dimensional Black Hole Solutions

    E-Print Network [OSTI]

    I-Ching Yang; Irina Radinschi

    2006-11-05

    The energy distributions of four 2+1 dimensional black hole solutions were obtained by using the Einstein and M{\\o}ller energy-momentum complexes. while $r \\to \\infty$, the energy distributions of these four solutions become divergence.

  1. Quantum Emission from Two-Dimensional Black Holes

    E-Print Network [OSTI]

    Steven B. Giddings; W. M. Nelson

    2009-11-27

    We investigate Hawking radiation from two-dimensional dilatonic black holes using standard quantization techniques. In the background of a collapsing black hole solution the Bogoliubov coefficients can be exactly determined. In the regime after the black hole has settled down to an `equilibrium' state but before the backreaction becomes important these give the known result of a thermal distribution of Hawking radiation at temperature lambda/(2pi). The density matrix is computed in this regime and shown to be purely thermal. Similar techniques can be used to derive the stress tensor. The resulting expression agrees with the derivation based on the conformal anomaly and can be used to incorporate the backreaction. Corrections to the thermal density matrix are also examined, and it is argued that to leading order in perturbation theory the effect of the backreaction is to modify the Bogoliubov transformation, but not in a way that restores information lost to the black holes.

  2. An Energy Extremum Principle for Charged Black Holes

    E-Print Network [OSTI]

    Fraser, Scott

    2015-01-01

    For a set of asymptotically flat black holes with arbitrary charges and masses, all initially at rest and well-separated, we prove the following extremum principle: the extremal charge configuration ($|q_i|=m_i$ for each black hole) can be derived by extremizing the total energy, for variations of the black hole apparent horizon areas, at fixed charges and fixed Euclidean separations. If all charges have the same sign, this result is a variational principle that reinterprets the static equilibrium of the Majumdar-Papapetrou-Hartle-Hawking solution as an extremum of total energy, rather than as a balance of forces; this result augments a list of related variational principles for static black holes, and is consistent with the independently known BPS energy minimum.

  3. An Energy Extremum Principle for Charged Black Holes

    E-Print Network [OSTI]

    Scott Fraser; Shaker Von Price Funkhouser

    2015-09-13

    For a set of asymptotically flat black holes with arbitrary charges and masses, all initially at rest and well-separated, we prove the following extremum principle: the extremal charge configuration ($|q_i|=m_i$ for each black hole) can be derived by extremizing the total energy, for variations of the black hole apparent horizon areas, at fixed charges and fixed Euclidean separations. If all charges have the same sign, this result is a variational principle that reinterprets the static equilibrium of the Majumdar-Papapetrou-Hartle-Hawking solution as an extremum of total energy, rather than as a balance of forces; this result augments a list of related variational principles for static black holes, and is consistent with the independently known BPS energy minimum.

  4. Energy Distribution of a Stringy Charged Black Hole

    E-Print Network [OSTI]

    Ragab M. Gad

    2003-06-22

    The energy distribution associated with a stringy charged black hole is studied using M{\\o}ller's energy-momentum complex. Our result is reasonable and it differs from that known in literature using Einstein's energy-momentum complex.

  5. Larger Black Flour Beetle in Southern High Plains Homes 

    E-Print Network [OSTI]

    Porter, Patrick; McIntyre, Nancy E.

    2007-04-09

    Larger black flour beetles have invaded homes and other buildings in some Southern High Plains counties in Texas. This publication explains how to identify the beetles, find and eliminate the source, and exclude the insects from the house....

  6. Black hole remnant in asymptotic Anti-de Sitter space

    E-Print Network [OSTI]

    Wen, Wen-Yu

    2015-01-01

    It is known that a solution of remnant were suggested for black hole ground state after surface gravity is corrected by loop quantum effect. On the other hand, a Schwarzschild black hole in asymptotic Anti-de Sitter space would tunnel into the thermal soliton solution known as the Hawking-Page phase transition. In this letter, we investigate the low temperature phase of three-dimensional BTZ black hole and four-dimensional AdS Schwarzschild black hole. We find that the thermal soliton is energetically favored than the remnant solution at low temperature in three dimensions, while Planck-size remnant is still possible in four dimensions. Though the BTZ remnant seems energetically disfavored, we argue that it is still possible to be found in the overcooled phase if strings were present and its implication is discussed.

  7. Spectral Properties of Galactic and Extragalactic Black Hole Candidates

    E-Print Network [OSTI]

    Sandip K. Chakrabarti

    1996-11-10

    We review current theoretical understanding of the spectral properties (low and high states, transition of states, quasi-periodic oscillations etc.) of the low mass as well as supermassive black hole candidates.

  8. Hooperchicks: Black Women, College Basketball and Identity Negotiation 

    E-Print Network [OSTI]

    Clay, Charity

    2014-08-14

    This project used in depth interviews with Black women who played Division I college basketball from1997-2007 to elucidate how they developed their racial, gender and athletic identities during adolescence, and how those ...

  9. Energy Department Announces New Technical Review to Assess Black...

    Energy Savers [EERE]

    being designed and built to treat millions of gallons of tank waste from plutonium production at Hanford from the 1940s to the 1980s. The equipment in the facility's 18 black...

  10. Black Hole Demographics from the M(BH)-sigma Relation

    E-Print Network [OSTI]

    David Merritt; Laura Ferrarese

    2001-03-03

    We analyze a sample of 32 galaxies for which a dynamical estimate of the mass of the hot stellar component, M_bulge, is available. For each of these galaxies, we calculate the mass of the central black hole, M_BH, using the tight empirical correlation between M_BH and the bulge stellar velocity dispersion. The frequency function N(log M_BH/M_bulge) is reasonably well described as a Gaussian with ~ -2.90 and standard deviation 0.45; the implied mean ratio of black hole to bulge mass is a factor 5 smaller than generally quoted in the literature. We present marginal evidence for a lower, average black-hole mass fraction in more massive galaxies. The total mass density in black holes in the local Universe is estimated to be 5 x 10^5 solar masses per cubic megaparsec, consistent with that inferred from high redshift (z ~ 2) AGNs.

  11. Electromagnetic quasinormal modes of D-dimensional black holes

    E-Print Network [OSTI]

    A. López-Ortega

    2006-11-02

    Using the monodromy method we calculate the asymptotic quasinormal (QN) frequencies of an electromagnetic field moving in D-dimensional Schwarzschild and Schwarzschild de Sitter (SdS) black holes ($D\\geq 4$). For the D-dimensional Schwarzschild anti-de Sitter (SadS) black hole we also compute these frequencies with a similar method. Moreover, we calculate the electromagnetic normal modes of the D-dimensional anti-de Sitter (AdS) spacetime.

  12. Linear waves in the interior of extremal black holes I

    E-Print Network [OSTI]

    Gajic, Dejan

    2015-01-01

    We consider solutions to the linear wave equation in the interior region of extremal Reissner-Nordstr\\"om black holes. We show that, under suitable assumptions on the initial data, the solutions can be extended continuously beyond the Cauchy horizon and moreover, that their local energy is finite. This result is in contrast with previously established results for subextremal Reissner-Nordstr\\"om black holes, where the local energy was shown to generically blow up at the Cauchy horizon.

  13. Black Hole Statistical Mechanics and The Angular Velocity Ensemble

    E-Print Network [OSTI]

    Mitchell Thomson; Charles C. Dyer

    2012-03-29

    An new ensemble - the angular velocity ensemble - is derived using Jaynes' method of maximising entropy subject to prior information constraints. The relevance of the ensemble to black holes is motivated by a discussion of external parameters in statistical mechanics and their absence from the Hamiltonian of general relativity. It is shown how this leads to difficulty in deriving entropy as a function of state and recovering the first law of thermodynamics from the microcanonical and canonical ensembles applied to black holes.

  14. Spectral Properties of Black Holes in Gamma Rays

    E-Print Network [OSTI]

    Sandip K. Chakrabarti

    2005-01-14

    Black holes are the most compact objects in the universe. Therefore, matter accreting onto is likely to radiate photons of energy comparable to very high gravitational potential energy. We discuss the nature of the emitted radiation in X-rays and gamma-rays from black hole candidates. We present theoretical solutions which comprise both Keplerian and sub-Keplerian components and suggest that shocks in accretion and outflows

  15. Bounding the greybody factors for Schwarzschild black holes

    E-Print Network [OSTI]

    Boonserm, Petarpa

    2008-01-01

    Greybody factors in black hole physics modify the naive Planckian spectrum that is predicted for Hawking radiation when working in the limit of geometrical optics. We consider the Schwarzschild geometry in (3+1) dimensions, and analyze the Regge-Wheeler equation for arbitrary particle spin S and wave-mode angular momentum L, deriving rigourous bounds on the greybody factors as a function of S, L, wave frequency (omega), and the black hole mass, m.

  16. Drum drying of black liquor using superheated steam impinging jets

    SciTech Connect (OSTI)

    Shiravi, A.H.; Mujumdar, A.S.; Kubes, G.J. [McGill Univ., Montreal, Quebec (Canada)

    1997-05-01

    A novel drum dryer for black liquor utilizing multiple impinging jets of superheated steam was designed and built to evaluate the performance characteristics and effects of various operating parameters thereon. Appropriate ranges of parameters such as steam jet temperature and velocity were examined experimentally to quantify the optimal operating conditions for the formation of black liquor film on the drum surface as well as the drying kinetics.

  17. MULTICOMPONENT SEISMIC ANALYSIS AND CALIBRATION TO IMPROVE RECOVERY FROM ALGAL MOUNDS: APPLICATION TO THE ROADRUNNER/TOWAOC AREA OF THE PARADOX BASIN, UTE MOUNTAIN UTE RESERVATION, COLORADO

    SciTech Connect (OSTI)

    Paul La Pointe; Claudia Rebne; Steve Dobbs

    2003-07-10

    This report describes the results made in fulfillment of contract DE-FG26-02NT15451, ''Multicomponent Seismic Analysis and Calibration to Improve Recovery from Algal Mounds: Application to the Roadrunner/Towaoc Area of the Paradox Basin, Ute Mountain Ute Reservation, Colorado''. Optimizing development of highly heterogeneous reservoirs where porosity and permeability vary in unpredictable ways due to facies variations can be challenging. An important example of this is in the algal mounds of the Lower and Upper Ismay reservoirs of the Paradox Basin in Utah and Colorado. It is nearly impossible to develop a forward predictive model to delineate regions of better reservoir development, and so enhanced recovery processes must be selected and designed based upon data that can quantitatively or qualitatively distinguish regions of good or bad reservoir permeability and porosity between existing well control. Recent advances in seismic acquisition and processing offer new ways to see smaller features with more confidence, and to characterize the internal structure of reservoirs such as algal mounds. However, these methods have not been tested. This project will acquire cutting edge, three-dimensional, nine-component (3D9C) seismic data and utilize recently-developed processing algorithms, including the mapping of azimuthal velocity changes in amplitude variation with offset, to extract attributes that relate to variations in reservoir permeability and porosity. In order to apply advanced seismic methods a detailed reservoir study is needed to calibrate the seismic data to reservoir permeability, porosity and lithofacies. This will be done by developing a petrological and geological characterization of the mounds from well data; acquiring and processing the 3D9C data; and comparing the two using advanced pattern recognition tools such as neural nets. In addition, should the correlation prove successful, the resulting data will be evaluated from the perspective of selecting alternative enhanced recovery processes, and their possible implementation. The work is being carried out on the Roadrunner/Towaoc Fields of the Ute Mountain Ute Tribe, located in the southwestern corner of Colorado. Although this project is focused on development of existing resources, the calibration established between the reservoir properties and the 3D9C seismic data can also enhance exploration success. During the time period covered by this report, the majority of the project effort has gone into the permitting, planning and design of the 3D seismic survey, and to select a well for the VSP acquisition. The business decision in October, 2002 by WesternGeco, the projects' seismic acquisition contractor, to leave North America, has delayed the acquisition until late summer, 2003. The project has contracted Solid State, a division of Grant Geophysical, to carry out the acquisition. Moreover, the survey has been upgraded to a 3D9C from the originally planned 3D3C survey, which should provide even greater resolution of mounds and internal mound structure.

  18. Masses of Stellar Black Holes and Testing Theories of Gravitation

    E-Print Network [OSTI]

    K. A. Postnov; A. M. Cherepashchuk

    2004-01-22

    We analyze the mass distribution of stellar black holes derived from the light and radial velocity curves of optical stars in close binary systems using dynamical methods. The systematic errors inherent in this approach are discussed. These are associated primarily with uncertainties in models for the contribution from gaseous structures to the optical brightness of the systems under consideration. The mass distribution is nearly flat in the range 4-15M_sun. This is compared with the mass distribution for black holes in massive close binaries, which can be manifest as ultraluminous X-ray sources (L_x > 10^39 erg/s) observed in other galaxies. If the X-ray luminosities of these objects correspond to the Eddington limit, the black-hole mass distribution should be described by a power law, which is incompatible with the flat shape derived dynamically from observations of close binaries in our Galaxy. One possible explanation of this discrepancy is the rapid evaporation of stellar-mass black holes predicted in recent multi-dimensional models of gravity. This hypothesis can be verifed by measuring the stellar black-hole mass spectrum or finding isolated or binary black holes with masses below 3M_sun.

  19. Energy spectrum of black holes : a new view

    E-Print Network [OSTI]

    Abhishek Majhi

    2015-12-22

    Energy of a black hole is usually quantized by invoking some area quantization scheme after expressing the energy in terms of the horizon area. However, in this approach one has to quantize the local and asymptotic energy of the black hole separately and the two results do not manifest any physical correspondence with each other. Here, as opposed to this practice, we find the unique energy spectrum of black holes by adopting a top-down approach. The physical links among the underlying quantum theory, statistical mechanics and thermodynamics of the black hole horizon play the central role in determining the energy spectrum. The energy spectrum that we obtain, explicitly reveals the correspondence between asymptotic and local observations through the presence of the surface gravity of the horizon as a parameter in the spectrum, rather than being expressed as a function of area and consequently getting quantized in the usual approach. Thus, our result presents a new view as far as black hole energy quantization is concerned. The calculations are performed using the quantum geometric description of black hole horizons as laid down by loop quantum gravity.

  20. Spin alignment and differential accretion in merging black hole binaries

    E-Print Network [OSTI]

    Davide Gerosa; Benedetta Veronesi; Giuseppe Lodato; Giovanni Rosotti

    2015-07-01

    Interactions between a supermassive black hole binary and the surrounding accretion disc can both assist the binary inspiral and align the black hole spins to the disc angular momentum. While binary migration is due to angular-momentum transfer within the circumbinary disc, the spin-alignment process is driven by the mass accreting on to each black hole. Mass transfer between different disc components thus couples the inspiral and the alignment process together. Mass is expected to leak through the cavity cleared by the binary, and preferentially accretes on to the lighter (secondary) black hole which orbits closer to the disc edge. Low accretion rate on to the heavier (primary) black hole slows the alignment process down. We revisit the problem and develop a semi-analytical model to describe the coupling between gas-driven inspiral and spin alignment, finding that binaries with mass ratio qprimaries from aligning. Binary black holes with misaligned primaries are ideal candidates for precession effects in the strong-gravity regime and may suffer from moderately large (~1500 km/s) recoil velocities.

  1. Relating Follicly-Challenged Compact Stars to Bald Black Holes

    E-Print Network [OSTI]

    Kent Yagi; Nicolas Yunes

    2015-07-08

    Compact stars satisfy certain no-hair relations through which their multipole moments are given by their mass, spin and quadrupole moment. These relations are approximately independent of their equation of state, relating pressure to density. Such relations are similar to the black hole no-hair theorems, but these possess event horizons inside which information that led to their formation can hide. Compact stars do not possess horizons, so whether their no-hair relations are related to the black hole ones is unclear. We investigate how the two relations are related by studying relations among multipole moments for compact stars with anisotropic pressure as a toy model, which allows such stars to be more compact than those with isotropic pressure. We here show numerically that the compact star no-hair relations approach the black hole ones as the compactness approaches that of a black hole. We also prove analytically that the current dipole moment exactly reaches the black hole limit quadratically in compactness as strongly-anisotropic stars approach the black hole limit. We moreover show that compact stars become progressively oblate in this limit, even if prolate at low compactness due to strong anisotropies.

  2. Nonlinearly charged Lifshitz black holes for any exponent $z>1$

    E-Print Network [OSTI]

    Abigail Alvarez; Eloy Ayón-Beato; Hernán A. González; Mokhtar Hassaïne

    2015-01-27

    Charged Lifshitz black holes for the Einstein-Proca-Maxwell system with a negative cosmological constant in arbitrary dimension $D$ are known only if the dynamical critical exponent is fixed as $z=2(D-2)$. In the present work, we show that these configurations can be extended to much more general charged black holes which in addition exist for any value of the dynamical exponent $z>1$ by considering a nonlinear electrodynamics instead of the Maxwell theory. More precisely, we introduce a two-parametric nonlinear electrodynamics defined in the more general, but less known, so-called $(\\mathcal{H},P)$-formalism and obtain a family of charged black hole solutions depending on two parameters. We also remark that the value of the dynamical exponent $z=D-2$ turns out to be critical in the sense that it yields asymptotically Lifshitz black holes with logarithmic decay supported by a particular logarithmic electrodynamics. All these configurations include extremal Lifshitz black holes. Charged topological Lifshitz black holes are also shown to emerge by slightly generalizing the proposed electrodynamics.

  3. Stability of black holes based on horizon thermodynamics

    E-Print Network [OSTI]

    Ma, Meng-Sen

    2015-01-01

    On the basis of horizon thermodynamics we study the thermodynamic stability of black holes constructed in general relativity and Gauss-Bonnet gravity. In the framework of horizon thermodynamics there are only five thermodynamic variables $E,P,V,T,S$. It is not necessary to consider concrete matter fields, which may contribute to the pressure of black hole thermodynamic system. In non-vacuum cases, we can derive the equation of state, $P=P(V,T)$. According to the requirements of stable equilibrium in conventional thermodynamics, we start from these thermodynamic variables to calculate the heat capacity at constant pressure and Gibbs free energy and analyze the local and global thermodynamic stability of black holes. It is shown that $P>0$ is the necessary condition for black holes in general relativity to be thermodynamically stable, however this condition cannot be satisfied by many black holes in general relativity. For black hole in Gauss-Bonnet gravity negative pressure can be feasible, but only local stab...

  4. Bright vigorous winds as signposts of supermassive black hole birth

    E-Print Network [OSTI]

    Fiacconi, Davide

    2015-01-01

    The formation of supermassive black holes is still an outstanding question. In the quasi-star scenario, black hole seeds experience an initial super-Eddington growth, that in less than a million years may leave a $10^4-10^5$ M$_{\\odot}$ black hole at the centre of a protogalaxy at $z \\sim 20-10$. Super-Eddington accretion, however, may be accompanied by vigorous mass loss that can limit the amount of mass that reaches the black hole. In this paper, we critically assess the impact of radiative driven winds, launched from the surface of the massive envelopes from which the black hole accretes. Solving the full wind equations coupled with the hydrostatic structure of the envelope, we find mass outflows with rates between a few tens and $10^4$ M$_{\\odot}$ yr$^{-1}$, mainly powered by advection luminosity within the outflow. We therefore confirm the claim by Dotan, Rossi & Shaviv (2011) that mass losses can severely affect the black hole seed early growth within a quasi-star. In particular, seeds with mass $>1...

  5. The mass function of high redshift seed black holes

    E-Print Network [OSTI]

    Giuseppe Lodato; Priyamvada Natarajan

    2007-02-13

    In this paper we derive the mass function of seed black holes that result from the central mass concentrated via disc accretion in collapsed haloes at redshift $z\\approx 15$. Using standard arguments including stability, we show that these pre-galactic discs can assemble a significant mass concentration in the inner regions, providing fuel for the formation and initial growth of super-massive black holes. Assuming that these mass concentrations do result in central seed black holes, we determine the mass distribution of these seeds as a function of key halo properties. The seed mass distribution determined here turns out to be asymmetric and skewed to higher masses. Starting with these initial seeds, building up to $10^9$ solar masses by $z = 6$ to power the bright quasars is not a problem in the standard LCDM cosmogony. These seed black holes in gas rich environments are likely to grow into the supermassive black holes at later times via mergers and accretion. Gas accretion onto these seeds at high redshift will produce miniquasars that likely play an important role in the reionization of the Universe. Some of these seed black holes on the other hand could be wandering in galaxy haloes as a consequence of frequent mergers, powering the off-nuclear ultra-luminous X-ray sources detected in nearby galaxies.

  6. Head black woman in charge: An investigation of how black female athletic directors negotiate their race, gender, and class identities 

    E-Print Network [OSTI]

    McDowell, Jacqueline

    2009-05-15

    Framed as an instrumental case study, the purpose of this investigation was to understand how a select group of women, Black female athletic directors, define and negotiate their race, gender, and class identities. Data ...

  7. I am Black AND Jewish: Black Jewish Women’s Experiences in “White” Jewish Communities in Brazil

    E-Print Network [OSTI]

    Gondek, Abby S.

    2008-01-01

    the contemporary black movement in Brazil. In R. Reichmann (Race in contemporary Brazil (pp. 155-166). University Park,J.J. Crocitti (Eds. ), The Brazil reader: History, culture,

  8. Love isn't always black and white: understanding black-white interracial couples, their challenges, and their dyadic communication 

    E-Print Network [OSTI]

    Wilson, Misty Michelle

    2009-05-15

    While a great deal of sociological and psychological research has been done on black-white interracial couples and the challenges they have faced in past eras, the communication between the partners remains largely ...

  9. Black holes in young stellar clusters

    SciTech Connect (OSTI)

    Goswami, Sanghamitra; Kiel, Paul; Rasio, Frederic A. [Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208 (United States)

    2014-02-01

    We present theoretical models for stellar black hole (BH) properties in young, massive star clusters. Using a Monte Carlo code for stellar dynamics, we model realistic star clusters with N ? 5 × 10{sup 5} stars and significant binary fractions (up to 50%) with self-consistent treatments of stellar dynamics and stellar evolution. We compute the formation rates and characteristic properties of single and binary BHs for various representative ages, cluster parameters, and metallicities. Because of dynamical interactions and supernova (SN) kicks, more single BHs end up retained in clusters compared to BHs in binaries. We also find that the ejection of BHs from a cluster is a strong function of initial density. In low-density clusters (where dynamical effects are negligible), it is mainly SN kicks that eject BHs from the cluster, whereas in high-density clusters (initial central density ? {sub c}(0) ? 10{sup 5} M {sub ?} pc{sup –3} in our models) the BH ejection rate is enhanced significantly by dynamics. Dynamical interactions of binary systems in dense clusters also modify the orbital period and eccentricity distributions while increasing the probability of a BH having a more massive companion.

  10. Black Hole Spectral States and Physical Connections

    E-Print Network [OSTI]

    John A. Tomsick

    2005-09-06

    The dramatic changes seen in the X-ray spectral and timing properties of accreting black hole candidates (BHCs) provide important clues about the accretion and jet formation processes that occur in these systems. Dividing the different source behaviors into spectral states provides a framework for studying BHCs. To date, there have been three main classification schemes with Luminosity-based, Component-based, or Transition-based criteria. The canonical, Luminosity-based criteria and physical models that are based on this concept do not provide clear explanations for several phenomena, including hysteresis of spectral states and the presence of jets. I discuss the re-definitions of states, focusing on an application of the Component-based states to more than 400 RXTE observations of the recurrent BHC 4U 1630-47. We compare the X-ray properties for the recent 2002-2004 outburst to those of an earlier (1998) outburst, during which radio jets were observed. The results suggest a connection between hysteresis of states and major jet ejections, and it is possible that both of these are related to the evolution of the inner radius of the optically thick accretion disk.

  11. Galaxies nurtured by mature black holes

    E-Print Network [OSTI]

    Morikawa, Masahiro

    2015-01-01

    Supermassive black holes (SMBH) of size $10^{6-10}M_{\\odot}$ are common in the Universe and they define the center of the galaxies. A galaxy and the SMBH are generally thought to have co-evolved. However, the SMBH cannot evolve so fast as commonly observed even at redshift $z>6$. Therefore, we explore a natural hypothesis that the SMBH has been already formed mature at $z\\gtrapprox10$ before stars and galaxies. The SMBH forms energetic jets and outflows which trigger massive star formation in the ambient gas. They eventually construct globular clusters and classical bulge as well as the body of elliptical galaxies. We propose simple models which implement these processes. We point out that the globular clusters and classical bulges have a common origin but are in different phases. The same is true for the elliptical and spiral galaxies. Physics behind these phase division is the runaway star formation process with strong feedback to SMBH. This is similar to the forest-fire model that displays self-organized c...

  12. Thermodynamics of Black Hole Horizons and Kerr/CFT Correspondence

    E-Print Network [OSTI]

    Bin Chen; Shen-xiu Liu; Jia-ju Zhang

    2012-11-02

    In this paper we investigate the thermodynamics of the inner horizon and its implication on the holographic description of the black hole. We focus on the black holes with two physical horizons. Under reasonable assumption, we prove that the first law of thermodynamics of the outer horizon always indicates that of the inner horizon. As a result, the fact that the area product being mass-independent is equivalent to the relation $T_+S_+=T_-S_-$, with $T_\\pm$ and $S_\\pm$ being the Hawking temperatures and the entropies of the outer and inner horizon respectively. We find that the mass-independence of area product breaks down in general Myers-Perry black holes with spacetime dimension $d\\geq6$ and Kerr-AdS black holes with $d\\geq4$. Moreover we discuss the implication of the first laws of the outer and inner horizons on the thermodynamics of the right- and left-moving sectors of dual CFT in Kerr/CFT correspondence. We show that once the relation $T_+S_+=T_-S_-$ is satisfied, the central charges of two sectors must be same. Furthermore from the thermodynamics relations, we read the dimensionless temperatures of microscopic CFT, which are in exact agreement with the ones obtained from hidden conformal symmetry in the low frequency scattering off the black holes, and then determine the central charges. This method works well in well-known cases in Kerr/CFT correspondence, and reproduce successfully the holographic pictures for 4D Kerr-Newman and 5D Kerr black holes. We go on to predict the central charges and temperatures of a possible holographic CFT description dual to 5D doubly rotating black ring.

  13. Constraining Black Hole Spin Via X-ray Spectroscopy

    E-Print Network [OSTI]

    Laura W. Brenneman; Christopher S. Reynolds

    2006-08-23

    We present an analysis of the observed broad iron line feature and putative warm absorber in the long 2001 XMM-Newton observation of the Seyfert-1.2 galaxy MCG-6-30-15. The new "kerrdisk" model we have designed for simulating line emission from accretion disk systems allows black hole spin to be a free parameter in the fit, enabling the user to formally constrain the angular momentum of a black hole, among other physical parameters of the system. In an important extension of previous work, we derive constraints on the black hole spin in MCG-6-30-15 using a self-consistent model for X-ray reflection from the surface of the accretion disk while simultaneously accounting for absorption by dusty photoionized material along the line of sight (the warm absorber). Even including these complications, the XMM-Newton/EPIC-pn data require extreme relativistic broadening of the X-ray reflection spectrum; assuming no emission from within the radius of marginal stability, we derive a formal constraint on the dimensionless black hole spin parameter of a > 0.987 at 90% confidence. The principal unmodeled effect that can significantly reduce the inferred black hole spin is powerful emission from within the radius of marginal stability. Although significant theoretical developments are required to fully understand this region, we argue that the need for a rapidly spinning black hole is robust to physically plausible levels of emission from within the radius of marginal stability. In particular, we show that a non-rotating black hole is strongly ruled out.

  14. Ehrenfest scheme for $P-V$ criticality of higher dimensional charged black holes, rotating black holes and Gauss-Bonnet AdS black holes

    E-Print Network [OSTI]

    Mo, Jie-Xiong

    2014-01-01

    To provide an analytic verification of the nature of phase transition at the critical point of $P-V$ criticality, the original expressions of Ehrenfest equations have been introduced directly. By treating the cosmological constant and its conjugate quantity as thermodynamic pressure and volume respectively, we carry out analytical check of classical Ehrenfest equations. To show that our approach is universal, we investigate not only higher-dimensional charged AdS black holes, but also rotating AdS black holes. Not only are the examples of Einstein gravity shown, but also the example of modified gravity is presented for Gauss-Bonnet AdS black holes. The specific heat at constant pressure $C_P$, the volume expansion coefficient $\\alpha$ and the isothermal compressibility coefficient $\\kappa_T$ are found to diverge exactly at the critical point. It has been verified that both Ehrenfest equations hold at the critical point of $P-V$ criticality in the extended phase spaces of AdS black holes. So the nature of the ...

  15. Thermodynamics of Three-dimensional Black Holes via Charged Particle Absorption

    E-Print Network [OSTI]

    Gwak, Bogeun

    2015-01-01

    We have shown that changes occur in a (2+1)-dimensional charged black hole by adding a charged probe. The particle increases the entropy of the black hole and guarantees the second law of thermodynamics. The first law of thermodynamics is derived from the change in the black hole mass. Using the particle absorption, we test the extremal black hole and find out that the mass of the extremal black hole increases more than the electric charge. Therefore, the outer horizon of the black hole still exists. However, the extremal condition becomes non-extremal.

  16. Can reducing black carbon emissions counteract global warming?

    SciTech Connect (OSTI)

    Tami C. Bond; Haolin Sun

    2005-08-15

    Field measurements and model results have recently shown that aerosols may have important climatic impacts. One line of inquiry has investigated whether reducing climate-warming soot or black carbon aerosol emissions can form a viable component of mitigating global warming. Black carbon is produced by poor combustion, from our example hard coal cooking fires for and industrial pulverized coal boilers. The authors review and acknowledge scientific arguments against considering aerosols and greenhouse gases in a common framework, including the differences in the physical mechanisms of climate change and relevant time scales. It is argued that such a joint consideration is consistent with the language of the United Nations Framework Convention on Climate Change. Results from published climate-modeling studies are synthesized to obtain a global warming potential for black carbon relative to that of CO{sub 2} (680 on a 100 year basis). This calculation enables a discussion of cost-effectiveness for mitigating the largest sources of black carbon. It is found that many emission reductions are either expensive or difficult to enact when compared with greenhouse gases, particularly in Annex I countries. Finally, a role for black carbon in climate mitigation strategies is proposed that is consistent with the apparently conflicting arguments raised during the discussion. Addressing these emissions is a promising way to reduce climatic interference primarily for nations that have not yet agreed to address greenhouse gas emissions and provides the potential for a parallel climate agreement. 31 refs., 3 figs., 1 tab.

  17. Topological black holes in Lovelock-Born-Infeld gravity

    SciTech Connect (OSTI)

    Dehghani, M. H.; Alinejadi, N.; Hendi, S. H.

    2008-05-15

    In this paper, we present topological black holes of third order Lovelock gravity in the presence of cosmological constant and nonlinear electromagnetic Born-Infeld field. Depending on the metric parameters, these solutions may be interpreted as black hole solutions with inner and outer event horizons, an extreme black hole or naked singularity. We investigate the thermodynamics of asymptotically flat solutions and show that the thermodynamic and conserved quantities of these black holes satisfy the first law of thermodynamic. We also endow the Ricci flat solutions with a global rotation and calculate the finite action and conserved quantities of these class of solutions by using the counterterm method. We compute the entropy through the use of the Gibbs-Duhem relation and find that the entropy obeys the area law. We obtain a Smarr-type formula for the mass as a function of the entropy, the angular momenta, and the charge, and compute temperature, angular velocities, and electric potential and show that these thermodynamic quantities coincide with their values which are computed through the use of geometry. Finally, we perform a stability analysis for this class of solutions in both the canonical and the grand-canonical ensemble and show that the presence of a nonlinear electromagnetic field and higher curvature terms has no effect on the stability of the black branes, and they are stable in the whole phase space.

  18. Semi-classical approach to quantum black holes

    E-Print Network [OSTI]

    Euro Spallucci; Anais Smailagic

    2014-10-07

    In this Chapter we would like to review a "~phenomenological~" approach taking into account the most fundamental feature of string theory or, more in general, of quantum gravity, whatever its origin, which is the existence of a minimal length in the space-time fabric. This length is generally identified with the Planck length, or the string length, but it could be also much longer down to the TeV region. A simple and effective way to keep track of the effects the minimal length in black hole geometries is to solve the Einstein equations with an energy momentum tensor describing non point-like matter. The immediate consequence is the absence of any curvature singularity. Where textbook solutions of the Einstein equations loose any physical meaning because of infinite tidal forces, we find a de Sitter vacuum core of high, but finite, energy density and pressure. An additional improvement regards the final stage of the black hole evaporation leading to a vanishing Hawking temperature even in the neutral, non-rotating, case. In spite of th simplicity of this model we are able to describe the final stage of the black hole evaporation, resulting in a cold remnant with a degenerate, extremal, horizon of radius of the order of the minimal length. In this chapter we shall describe only neutral, spherically symmetric, regular black holes although charged, rotating and higher dimensional black holes can be found in the literature.

  19. On geodesic dynamics in deformed black-hole fields

    E-Print Network [OSTI]

    Old?ich Semerák; Petra Suková

    2015-09-28

    "Almost all" seems to be known about isolated stationary black holes in asymptotically flat space-times and about the behaviour of {\\em test} matter and fields in their backgrounds. The black holes likely present in galactic nuclei and in some X-ray binaries are commonly being represented by the Kerr metric, but actually they are not isolated (they are detected only thanks to a strong interaction with the surroundings), they are not stationary (black-hole sources are rather strongly variable) and they also probably do not live in an asymptotically flat universe. Such "perturbations" may query the classical black-hole theorems (how robust are the latter against them?) and certainly affect particles and fields around, which can have observational consequences. In the present contribution we examine how the geodesic structure of the static and axially symmetric black-hole space-time responds to the presence of an additional matter in the form of a thin disc or ring. We use several different methods to show that geodesic motion may become chaotic, to reveal the strength and type of this irregularity and its dependence on parameters. The relevance of such an analysis for galactic nuclei is briefly commented on.

  20. Black hole spectroscopy from Loop Quantum Gravity models

    E-Print Network [OSTI]

    Aurelien Barrau; Xiangyu Cao; Karim Noui; Alejandro Perez

    2015-04-21

    Using Monte Carlo simulations, we compute the integrated emission spectra of black holes in the framework of Loop Quantum Gravity (LQG). The black hole emission rates are governed by the entropy whose value, in recent holographic loop quantum gravity models, was shown to agree at leading order with the Bekenstein-Hawking entropy. Quantum corrections depend on the Barbero-Immirzi parameter $\\gamma$. Starting with black holes of initial horizon area $A \\sim 10^2$ in Planck units, we present the spectra for different values of $\\gamma$. Each spectrum clearly decomposes in two distinct parts: a continuous background which corresponds to the semi-classical stages of the evaporation and a series of discrete peaks which constitutes a signature of the deep quantum structure of the black hole. We show that $\\gamma$ has an effect on both parts that we analyze in details. Finally, we estimate the number of black holes and the instrumental resolution required to experimentally distinguish between the considered models.

  1. Mass and Free Energy of Lovelock Black Holes

    E-Print Network [OSTI]

    David Kastor; Sourya Ray; Jennie Traschen

    2011-06-20

    An explicit formula for the ADM mass of an asymptotically AdS black hole in a generic Lovelock gravity theory is presented, identical in form to that in Einstein gravity, but multiplied by a function of the Lovelock coupling constants and the AdS curvature radius. A Gauss' law type formula relates the mass, which is an integral at infinity, to an expression depending instead on the horizon radius. This and other thermodynamic quantities, such as the free energy, are then analyzed in the limits of small and large horizon radius, yielding results that are independent of the detailed choice of Lovelock couplings. In even dimensions, the temperature diverges in both limits, implying the existence of a minimum temperature for black holes. The negative free energy of sufficiently large black holes implies the existence of a Hawking-Page transition. In odd dimensions the temperature still diverges for large black holes, which again have negative free energy. However, the temperature vanishes as the horizon radius tends to zero and sufficiently small black holes have positive specific heat.

  2. Dissipative accretion flows around a rotating black hole

    E-Print Network [OSTI]

    Santabrata Das; Sandip K. Chakrabarti

    2008-06-12

    We study the dynamical structure of a cooling dominated rotating accretion flow around a spinning black hole. We show that non-linear phenomena such as shock waves can be studied in terms of only three flow parameters, namely, the specific energy (${\\cal E}$), the specific angular momentum ($\\lambda$) and the accretion rate (${\\dot m}$) of the flow. We present all possible accretion solutions. We find that a significant region of the parameter space in the ${\\cal E}-\\lambda$ plane allows global accretion shock solutions. The effective area of the parameter space for which the Rankine-Hugoniot shocks are possible is maximum when the flow is dissipation free. It decreases with the increase of cooling effects and finally disappears when the cooling is high enough. We show that shock forms further away when the black hole is rotating compared to the solution around a Schwarzschild black hole with identical flow parameters at a large distance. However, in a normalized sense, the flow parameters for which the shocks form around the rotating black holes are produced shocks closer to the hole. The location of the shock is also dictated by the cooling efficiency in that higher the accretion rate (${\\dot m}$), the closer is the shock location. We believe that some of the high frequency quasi-periodic oscillations may be due to the flows with higher accretion rate around the rotating black holes.

  3. Colliding Axion-Dilaton Plane Waves from Black Holes

    E-Print Network [OSTI]

    Patricia Schwarz

    1997-08-01

    The colliding plane wave metric discovered by Ferrari and Iba\\~{n}ez to be locally isometric to the interior of a Schwarzschild black hole is extended to the case of general axion-dilaton black holes. Because the transformation maps either black hole horizon to the focal plane of the colliding waves, this entire class of colliding plane wave spacetimes only suffers from the formation of spacetime singularities in the limits where the inner horizon itself is singular, which occur in the Schwarzschild and dilaton black hole limits. The supersymmetric limit corresponding to the extreme axion-dilaton black hole yields the Bertotti-Robinson metric with the axion and dilaton fields flowing to fixed constant values. The maximal analytic extension of this metric across the Cauchy horizon yields a spacetime in which two sandwich waves in a cylindrical universe collide to produce a semi-infinite chain of Reissner-Nordstrom-like wormholes. The focussing of particle and string geodesics in this spacetime is explored.

  4. The mass function of high redshift seed black holes

    E-Print Network [OSTI]

    Lodato, G; Lodato, Giuseppe; Natarajan, Priyamvada

    2007-01-01

    In this paper we derive the mass function of seed black holes that result from the central mass concentrated via disc accretion in collapsed haloes at redshift $z\\approx 15$. Using standard arguments including stability, we show that these pre-galactic discs can assemble a significant mass concentration in the inner regions, providing fuel for the formation and initial growth of super-massive black holes. Assuming that these mass concentrations do result in central seed black holes, we determine the mass distribution of these seeds as a function of key halo properties. The seed mass distribution determined here turns out to be asymmetric and skewed to higher masses. Starting with these initial seeds, building up to $10^9$ solar masses by $z = 6$ to power the bright quasars is not a problem in the standard LCDM cosmogony. These seed black holes in gas rich environments are likely to grow into the supermassive black holes at later times via mergers and accretion. Gas accretion onto these seeds at high redshift ...

  5. Distorted black holes from a vacuum 5-d spherical solution

    E-Print Network [OSTI]

    Capistrano, Abraão J S; Ulhoa, Sergio C; Amorim, Ronni G G

    2015-01-01

    We study the deformation caused by the influence of extrinsic curvature on a vacuum spherically symmetric metric embedded in a 5-d bulk. In this sense, we investigate the produced stationary black-holes and derive general properties such as its mass and horizons. As an application, a test moving particle near such black-holes is also shown as well the distortion caused by extrinsic curvature on its movement. Accordingly, using asymptotically conformal flat condition on the extrinsic curvature and an analytical expansion of a set of \\emph{n}-scalar fields, we show that the resulting black holes must be large and constrained in the range $-1/2 \\leq n \\leq 1.8$ that are locally thermodynamically stable, but not globally preferred.

  6. Thermoelectric DC conductivities and Stokes flows on black hole horizons

    E-Print Network [OSTI]

    Elliot Banks; Aristomenis Donos; Jerome P. Gauntlett

    2015-07-15

    We consider a general class of electrically charged black holes of Einstein-Maxwell-scalar theory that are holographically dual to conformal field theories at finite charge density which break translation invariance explicitly. We examine the linearised perturbations about the solutions that are associated with the thermoelectric DC conductivity. We show that there is a decoupled sector at the black hole horizon which must solve generalised Stokes equations for a charged fluid. By solving these equations we can obtain the DC conductivity of the dual field theory. For one-dimensional lattices we solve the fluid equations to obtain closed form expressions for the DC conductivity in terms of the solution at the black hole horizon. We also determine the leading order DC conductivity for lattices that can be expanded as a perturbative series about translationally invariant solutions.

  7. Exploring Higher Dimensional Black Holes at the Large Hadron Collider

    E-Print Network [OSTI]

    C. M. Harris; M. J. Palmer; M. A. Parker; P. Richardson; A. Sabetfakhri; B. R. Webber

    2004-11-01

    In some extra dimension theories with a TeV fundamental Planck scale, black holes could be produced in future collider experiments. Although cross sections can be large, measuring the model parameters is difficult due to the many theoretical uncertainties. Here we discuss those uncertainties and then we study the experimental characteristics of black hole production and decay at a typical detector using the ATLAS detector as a guide. We present a new technique for measuring the temperature of black holes that applies to many models. We apply this technique to a test case with four extra dimensions and, using an estimate of the parton-level production cross section error of 20%, determine the Planck mass to 15% and the number of extra dimensions to +-0.75.

  8. Holographic Superconductors with Ho?ava-Lifshitz Black Holes

    E-Print Network [OSTI]

    Rong-Gen Cai; Hai-Qing Zhang

    2009-12-03

    We discuss the phase transition of planar black holes in Ho\\v{r}ava-Lifshitz gravity by introducing a Maxwell field and a complex scalar field. We calculate the condensates of the charged operators in the dual CFTs when the mass square of the complex scalar filed is $m^2=-2/L^2$ and $m^2=0$, respectively. We compute the electrical conductivity of the \\hl superconductor in the probe approximation. In particular, it is found that there exists a spike in the conductivity for the case of the operator with scaling dimension one. These results are quite similar to those in the case of Schwarzschild-AdS black holes, which demonstrates that the holographic superconductivity is a robust phenomenon associated with asymptotic AdS black holes.

  9. Black hole feedback in the luminous quasar PDS 456

    E-Print Network [OSTI]

    Nardini, E; Gofford, J; Harrison, F A; Risaliti, G; Braito, V; Costa, M T; Matzeu, G A; Walton, D J; Behar, E; Boggs, S E; Christensen, F E; Craig, W W; Hailey, C J; Matt, G; Miller, J M; O'Brien, P T; Stern, D; Turner, T J; Ward, M J

    2015-01-01

    The evolution of galaxies is connected to the growth of supermassive black holes in their centers. During the quasar phase, a huge luminosity is released as matter falls onto the black hole, and radiation-driven winds can transfer most of this energy back to the host galaxy. Over five different epochs, we detected the signatures of a nearly spherical stream of highly ionized gas in the broadband X-ray spectra of the luminous quasar PDS 456. This persistent wind is expelled at relativistic speeds from the inner accretion disk, and its wide aperture suggests an effective coupling with the ambient gas. The outflow's kinetic power larger than 10^46 ergs per second is enough to provide the feedback required by models of black hole and host galaxy co-evolution.

  10. Thermodynamics of de Sitter Black Holes: Thermal Cosmological Constant

    E-Print Network [OSTI]

    Yuichi Sekiwa

    2006-04-10

    We study the thermodynamic properties associated with the black hole event horizon and the cosmological horizon for black hole solutions in asymptotically de Sitter spacetimes. We examine thermodynamics of these horizons on the basis of the conserved charges according to Teitelboim's method. In particular, we have succeeded in deriving the generalized Smarr formula among thermodynamical quantities in a simple and natural way. We then show that cosmological constant must decrease when one takes into account the quantum effect. These observations have been obtained if and only if cosmological constant plays the role of a thermodynamical state variable. We also touch upon the relation between inflation of our universe and a phase transition of black holes.

  11. Hard, infrared black coating with very low outgassing

    SciTech Connect (OSTI)

    Kuzmenko, P J; Behne, D M; Casserly, T; Boardman, W; Upadhyaya, D; Boinapally, K; Gupta, M; Cao, Y

    2008-06-02

    Infrared astronomical instruments require absorptive coatings on internal surfaces to trap scattered and stray photons. This is typically accomplished with any one of a number of black paints. Although inexpensive and simple to apply, paint has several disadvantages. Painted surfaces can be fragile, prone to shedding particles, and difficult to clean. Most importantly, the vacuum performance is poor. Recently a plasma enhanced chemical vapor deposition (PECVD) process was developed to apply thick (30 {micro}m) diamond-like carbon (DLC) based protective coatings to the interior of oil pipelines. These DLC coatings show much promise as an infrared black for an ultra high vacuum environment. The coatings are very robust with excellent cryogenic adhesion. Their total infrared reflectivity of < 10% at normal incidence approaches that of black paints. We measured outgas rates of <10{sup -12} Torr liter/sec cm{sup 2}, comparable to bare stainless steel.

  12. Aspects of Accretion Processes On a Rotating Black Hole

    E-Print Network [OSTI]

    Sandip K. Chakrabarti

    1996-11-10

    We describe the most general nature of accretion and wind flows around a compact object and emphasize on the properties which are special to black hole accretion. The angular momentum distribution in the most general solution is far from Keplerian, and the non-Keplerian disks can include standing shock waves. We also present fully time dependent numerical simulation results to show that they agree with these analytical solutions. We describe the spectral properties of these accretion disks and show that the soft and hard states of the black hole candidates could be explained by the change of the accretion rate of the disk. We present fits of the observational data to demonstrate the presence of sub-Keplerian flows around black holes.

  13. Satellite observations of thought experiments close to a black hole

    E-Print Network [OSTI]

    S. K. Chakrabarti

    2000-07-18

    Since black holes are `black', methods of their identification must necessarily be indirect. Due to very special boundary condition on the horizon, the advective flow behaves in a particular way, which includes formation of centrifugal pressure dominated boundary layer or CENBOL where much of the infall energy is released and outflows are generated. The observational aspects of black holes must depend on the steady and time-dependent properties of this boundary layer. Several observational results are written down in this review which seem to support the predictions of thought experiments based on this advective accretion/outflow model. In future, when gravitational waves are detected, some other predictions of this model could be tested as well.

  14. On the wave energy potential of Western Black Sea shelf

    E-Print Network [OSTI]

    Galabov, Vasko

    2013-01-01

    In the present study we evaluate the approaches to estimate the wave energy potential of the western Black Sea shelf with numerical models. For the purpose of our evaluation and due to the lack of long time series of measurements in the selected area of the Black Sea, we compare the modeled mean wave power flux output from the SWAN wave model with the only available long term measurements from the buoy of Gelendzhik for the period 1997-2003 (with gaps). The forcing meteorological data for the numerical wave models for the selected years is extracted from the ERA Interim reanalysis of ECMWF (European Centre for Medium range Forecasts). For the year 2003 we also compare the estimated wave power with the modeled by SWAN, using ALADIN regional atmospheric model winds. We try to identify the shortcomings and limitations of the numerical modeling approach to the evaluation of the wave energy potential in Black Sea.

  15. Thermoelectric DC conductivities and Stokes flows on black hole horizons

    E-Print Network [OSTI]

    Banks, Elliot; Gauntlett, Jerome P

    2015-01-01

    We consider a general class of electrically charged black holes of Einstein-Maxwell-scalar theory that are holographically dual to conformal field theories at finite charge density which break translation invariance explicitly. We examine the linearised perturbations about the solutions that are associated with the thermoelectric DC conductivity. We show that there is a decoupled sector at the black hole horizon which must solve generalised Stokes equations for a charged fluid. By solving these equations we can obtain the DC conductivity of the dual field theory. For one-dimensional lattices we solve the fluid equations to obtain closed form expressions for the DC conductivity in terms of the solution at the black hole horizon. We also determine the leading order DC conductivity for lattices that can be expanded as a perturbative series about translationally invariant solutions.

  16. Thermoelectric DC conductivities and Stokes flows on black hole horizons

    E-Print Network [OSTI]

    Elliot Banks; Aristomenis Donos; Jerome P. Gauntlett

    2015-10-11

    We consider a general class of electrically charged black holes of Einstein-Maxwell-scalar theory that are holographically dual to conformal field theories at finite charge density which break translation invariance explicitly. We examine the linearised perturbations about the solutions that are associated with the thermoelectric DC conductivity. We show that there is a decoupled sector at the black hole horizon which must solve generalised Stokes equations for a charged fluid. By solving these equations we can obtain the DC conductivity of the dual field theory. For Q-lattices and one-dimensional lattices we solve the fluid equations to obtain closed form expressions for the DC conductivity in terms of the solution at the black hole horizon. We also determine the leading order DC conductivity for lattices that can be expanded as a perturbative series about translationally invariant solutions.

  17. "Put One More 'S' in the USA": Communist Pamphlet Literature and the Productive Fiction of the Black Nation Thesis

    E-Print Network [OSTI]

    Sangrey, Trevor Joy

    2012-01-01

    Organizations Black Nation Thesis Pamphlets 4 Free 5 inMovement in the colonies: Thesis on the revolutionaryof the Black Nation Thesis. Berkeley: Racism Research

  18. Biogeochemical Signatures in Precambrian Black Shales: Window Into the Co-Evolution of Ocean Chemistry and Life on Earth

    E-Print Network [OSTI]

    Scott, Clinton

    2009-01-01

    concentration in black shales: EXAFS evidence. Geochimica etOs and 2316Ma age for marine shale: implications forconcentration in black shales: EXAFS evidence. Geochimica et

  19. Black Radicals Make for Bad Citizens: Undoing the Myth of the School to Prison Pipeline

    E-Print Network [OSTI]

    Sojoyner, Damien M

    2013-01-01

    December 13). Prison pipeline hits Black students harder,http://politic365.com/2012/12/13/prison-pipeline-hits-black-The school-to-prison pipeline: Structuring legal reform. New

  20. Understanding Black Male Athlete Social Responsibility (BMASR): A Case Study of an NBA Franchise 

    E-Print Network [OSTI]

    Agyemang, Kwame Jesse Asamoah

    2012-07-16

    While there is voluminous research on the Black male athlete, the literature does not touch on the notion of social responsibility. Thus, the purpose of this study was to garner perceptions of Black male athlete social ...

  1. Are You Planning to Buy Energy-Efficient Products on Black Friday...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Are You Planning to Buy Energy-Efficient Products on Black Friday? Are You Planning to Buy Energy-Efficient Products on Black Friday? November 23, 2011 - 5:09am Addthis This week,...

  2. Trace metal composition of suspended particulate matter in the water column of the Black Sea

    E-Print Network [OSTI]

    Murray, James W.

    Trace metal composition of suspended particulate matter in the water column of the Black Sea Ouz Keywords: Black Sea Geochemistry Biogeochemistry Biogeochemical cycle Trace metals Trace elements Tracers Particulates Suspended particulate matter Biogenic matter Biogenic material Plankton Planktonic metal

  3. Microstructure and Optical Properties of Black Chrome Before and After Exposure to High Temperatures

    E-Print Network [OSTI]

    Lapert, C.M.

    2011-01-01

    Black Chrome in Vacuum** Heat Treatment None, As-plated 200Black Chrome in Dry Air Heat Treatment None, As-plated 200°to short term heat treatments. The as-plated structure was

  4. The Color of Self-Love: Exposing Racism in Black Female Masturbation Research

    E-Print Network [OSTI]

    Frank, Elena

    2010-01-01

    Americans, Gender, and the New Racism. New York: Routledge,of Self-Love: Exposing Racism in Black Female Masturbationsexual deviance and construct racism and sexism. BLACK/WHITE

  5. Interaction of Supermassive Black Holes with their Stellar and Dark Matter Environments

    E-Print Network [OSTI]

    David Merritt

    2004-10-04

    A review of recent theoretical work on the interactions of supermassive single and binary black holes with their nuclear environments, highlighting ways in which the observed structure of nuclei can be used to constrain the formation history of black holes.

  6. Exact black hole solution with a minimally coupled scalar field

    E-Print Network [OSTI]

    Cristian Martinez; Ricardo Troncoso; Jorge Zanelli

    2004-06-13

    An exact four-dimensional black hole solution of gravity with a minimally coupled self-interacting scalar field is reported. The event horizon is a surface of negative constant curvature enclosing the curvature singularity at the origin, and the scalar field is regular everywhere outside the origin. This solution is an asymptotically locally AdS spacetime. The strong energy condition is satisfied on and outside the event horizon. The thermodynamical analysis shows the existence of a critical temperature, below which a black hole in vacuum undergoes a spontaneous dressing up with a nontrivial scalar field in a process reminiscent of ferromagnetism.

  7. Regular Black Holes in $f(R)$ Gravity

    E-Print Network [OSTI]

    Rodrigues, Manuel E; Marques, Glauber T; Zanchin, Vilson T

    2015-01-01

    We obtain a class of regular black hole solutions in four-dimensional $f(R)$ gravity, $R$ being the curvature scalar, coupled to a nonlinear electromagnetic source. The metric formalism is used and static spherically symmetric spacetimes are assumed. The resulting metric functions are given by one real parameter family of solutions which are generalization of known regular black hole solutions in General Relativity. The known solutions of General Relativity are recovered when the free parameter vanish in which case one has $f(R)\\propto R$. We show that there are particular cases that violates only the strong energy condition.

  8. Electromagnetic quasinormal modes of D-dimensional black holes II

    E-Print Network [OSTI]

    A. López-Ortega

    2007-06-20

    By using the sixth order WKB approximation we calculate for an electromagnetic field propagating in D-dimensional Schwarzschild and Schwarzschild de Sitter black holes its quasinormal frequencies for the fundamental mode and first overtones. We study the dependence of these QN frequencies on the value of the cosmological constant and the spacetime dimension. We also compare with the known results for the gravitational perturbations propagating in the same background. Moreover we exactly compute the QN frequencies of the electromagnetic field propagating in D-dimensional massless topological black hole and for charged D-dimensional Nariai spacetime we exactly calculate the QN frequencies of the coupled electromagnetic and gravitational perturbations.

  9. Supermassive Black Holes and the Evolution of Galaxies

    E-Print Network [OSTI]

    D. Richstone; E. A. Ajhar; R. Bender; G. Bower; A. Dressler; S. M. Faber; A. V. Filippenko; K. Gebhardt; R. Green; L. C. Ho; J. Kormendy; T. Lauer; J. Magorrian; S. Tremaine

    1998-10-23

    Black holes, an extreme consequence of the mathematics of General Relativity, have long been suspected of being the prime movers of quasars, which emit more energy than any other objects in the Universe. Recent evidence indicates that supermassive black holes, which are probably quasar remnants, reside at the centers of most galaxies. As our knowledge of the demographics of these relics of a violent earlier Universe improve, we see tantalizing clues that they participated intimately in the formation of galaxies and have strongly influenced their present-day structure.

  10. Relativistic Viscous Fluid Description of Microscopic Black Hole Wind

    E-Print Network [OSTI]

    J. I. Kapusta

    2001-05-25

    Microscopic black holes explode with their temperature varying inversely as their mass. Such explosions would lead to the highest temperatures in the present universe, all the way to the Planck energy. Whether or not a quasi-stationary shell of matter undergoing radial hydrodynamic expansion surrounds such black holes is been controversial. In this paper relativistic viscous fluid equations are applied to the problem. It is shown that a self-consistent picture emerges of a fluid just marginally kept in local thermal equilibrium; viscosity is a crucial element of the dynamics.

  11. Black liquor gasification phase 2D final report

    SciTech Connect (OSTI)

    Kohl, A.L.; Stewart, A.E.

    1988-06-01

    This report covers work conducted by Rockwell International under Amendment 5 to Subcontract STR/DOE-12 of Cooperative Agreement DE-AC-05-80CS40341 between St. Regis Corporation (now Champion International) and the Department of Energy (DOE). The work has been designated Phase 2D of the overall program to differentiate it from prior work under the same subcontract. The overall program is aimed at demonstrating the feasibility of and providing design data for the Rockwell process for gasifying Kraft black liquor. In this process, concentrated black liquor is converted into low-Btu fuel gas and reduced melt by reaction with air in a specially designed gasification reactor.

  12. Exploring higher dimensional black holes at the large hadron collider.

    E-Print Network [OSTI]

    Harris, Chris M.; Palmer, M. J.; Parker, Michael A.; Richardson, P.

    Preprint typeset in JHEP style - HYPER VERSION Cavendish-HEP-04/29 ATL-COM-PHYS-2004-067 Exploring Higher Dimensional Black Holes at the Large Hadron Collider C.M. Harris†, M.J. Palmer†, M.A. Parker†, P. Richardson‡, A. Sabetfakhri† and B.R. Webber... the Standard Model matter and gauge fields are confined to the physical three-branes in a higher dimensional space, it has been shown that most of the black hole decay products are Standard Model quanta emitted on the brane [7] and are therefore visible...

  13. Low energy 2+1 string gravity; black hole solutions

    E-Print Network [OSTI]

    A. A. Garcia Diaz; G. Gutierrez Cano

    2014-12-17

    In this report a detailed derivation of the dynamical equations for an n dimensional heterotic string theory of the Horowitz type is carried out in the string frame and in the Einstein frame too. In particular, the dynamical equations of the three dimensional string theory are explicitly given. The relation of the Horowitz Welch and Horne Horowitz string black hole solution is exhibited. The Chan Mann charged dilaton solution is derived and the subclass of string solutions field is explicitly identified. The stationary generalization, via SL(2;R) transformations, of the static (2+1) Horne Horowitz string black hole solution is given.

  14. Schwarzschild black hole levitating in the hyperextreme Kerr field

    E-Print Network [OSTI]

    V. S. Manko; E. Ruiz

    2015-11-05

    The equilibrium configurations between a Schwarzschild black hole and a hyperextreme Kerr object are shown to be described by a three-parameter subfamily of the extended double-Kerr solution. For this subfamily, its Ernst potential and corresponding metric functions, we provide a physical representation which employs as arbitrary parameters the individual Komar masses and relative coordinate distance between the sources. The calculation of horizon's local angular velocity induced in the Schwarzschild black hole by the Kerr constituent yields a simple expression inversely proportional to the square of the distance parameter.

  15. Thermodynamics of Schrödinger black holes with hyperscaling violation

    E-Print Network [OSTI]

    J. Sadeghi; B. Pourhassan; F. Pourasadollah

    2012-11-06

    In this work, we follow Kim and Yamada (JHEP1107 (2011) 120) and utilize AdS in light-cone frame to derive thermodynamic and transport properties of two kinds of Schr\\"{o}dinger black holes with hyperscaling violation. In that case, we show entropy and temperature are depend on $\\theta$. In $\\theta=0$ we see our results are agree with the work of Kim and Yamada. We also construct R-charged black hole with hyperscaling violation and obtain thermodynamics and transport properties.

  16. Quantum-corrected finite entropy of noncommutative acoustic black holes

    E-Print Network [OSTI]

    M. A. Anacleto; F. A. Brito; G. C. Luna; E. Passos; J. Spinelly

    2015-01-31

    In this paper we consider the generalized uncertainty principle in the tunneling formalism via Hamilton-Jacobi method to determine the quantum-corrected Hawking temperature and entropy for 2+1-dimensional noncommutative acoustic black holes. In our results we obtain an area entropy, a correction logarithmic in leading order, a correction term in subleading order proportional to the radiation temperature associated with the noncommutative acoustic black holes and an extra term that depends on a conserved charge. Thus, as in the gravitational case, there is no need to introduce the ultraviolet cut-off and divergences are eliminated.

  17. Quantum-corrected finite entropy of noncommutative acoustic black holes

    E-Print Network [OSTI]

    Anacleto, M A; Luna, G C; Passos, E; Spinelly, J

    2015-01-01

    In this paper we consider the generalized uncertainty principle in the tunneling formalism via Hamilton-Jacobi method to determine the quantum-corrected Hawking temperature and entropy for 2+1-dimensional noncommutative acoustic black holes. In our results we obtain an area entropy, a correction logarithmic in leading order, a correction term in subleading order proportional to the radiation temperature associated with the noncommutative acoustic black holes and an extra term that depends on a conserved charge. Thus, as in the gravitational case, there is no need to introduce the ultraviolet cut-off and divergences are eliminated.

  18. Energy distribution in the dyadosphere of a charged black hole

    E-Print Network [OSTI]

    S. S. Xulu

    2003-04-22

    The event horizon of a charged black hole is, according to Ruffini\\cite{Ruffini} and Preparata \\emph{et al.}\\cite{PreparataEtAl}, surrounded by a special region called the \\emph{dyadosphere} where the electromagnetic field exceeds the Euler-Heisenberg critical value for electron-positron pair production. We obtain the energy distribution in the dyadosphere region for a Reissner-Nordstr\\"{o}m black hole. We find that the energy-momentum prescriptions of Einstein, Landau-Lifshitz, Papapetrou, and Weinberg give the same and acceptable energy distribution.

  19. Anomalies, Chern-Simons Terms and Black Hole Entropy

    E-Print Network [OSTI]

    Tatsuo Azeyanagi; R. Loganayagam; Gim Seng Ng

    2015-05-11

    Recent derivations of Cardy-like formulae in higher dimensional field theories have opened up a way of computing, via AdS/CFT, universal contributions to black hole entropy from gravitational Chern-Simons terms. Based on the manifestly covariant formulation of the differential Noether charge for Chern-Simons terms proposed in arXiv:1407.6364, we compute the entropy and asymptotic charges for the rotating charged AdS black holes in higher dimensions at leading order of the fluid/gravity derivative expansion in the Einstein-Maxwell-Chern-Simons system. This gives a result that exactly matches the field theory predictions from Cardy-like formulae.

  20. Role of Disk models in Indentifying Astrophysical Black Holes

    E-Print Network [OSTI]

    Sandip K. Chakrabarti

    2005-01-14

    We discuss how disk models may limit the scope of identifying astrophysical black holes. We show that the standard Keplerian thin disk model, the thick disk model, slim disks, ADAFs etc. are fundamentally limited. We present the most complete solution to date called the advective accretion disk and discuss how it has the scope to address every observational aspects of a black hole. Though the magnetic field is not fully self-consistently taken care of yet, the details with which the present model can handle various issues successfully are astounding. We present some of the examples.

  1. Greybody factors for Myers–Perry black holes

    SciTech Connect (OSTI)

    Boonserm, Petarpa; Chatrabhuti, Auttakit Ngampitipan, Tritos; Visser, Matt

    2014-11-15

    The Myers–Perry black holes are higher-dimensional generalizations of the usual (3+1)-dimensional rotating Kerr black hole. They are of considerable interest in Kaluza–Klein models, specifically within the context of brane-world versions thereof. In the present article, we shall consider the greybody factors associated with scalar field excitations of the Myers–Perry spacetimes, and develop some rigorous bounds on these greybody factors. These bounds are of relevance for characterizing both the higher-dimensional Hawking radiation, and the super-radiance, that is expected for these spacetimes.

  2. Greybody factors for Myers-Perry black holes

    E-Print Network [OSTI]

    Boonserm, Petarpa; Ngampitipan, Tritos; Visser, Matt

    2014-01-01

    The Myers-Perry black holes are higher-dimensional generalizations of the usual (3+1)-dimensional rotating Kerr black hole. They are of considerable interest in Kaluza-Klein models, specifically within the context of brane-world versions thereof. In the present article we shall consider the greybody factors associated with scalar field excitations of the Myers-Perry spacetimes, and develop some rigorous bounds on these greybody factors. These bounds are of relevance for characterizing both the higher-dimensional Hawking radiation, and the super-radiance, that is expected for these spacetimes.

  3. Environmentalism and the Politics of Equity: Emergent Trends in the Black Community

    E-Print Network [OSTI]

    Bullard, Robert; Wright, Beverly Hendrix

    1987-01-01

    . That is, the abili ty of the tobacco giants to exercise their constitutional rights. Tobacco and liquor companies provide generous contributions to black "causes" and buy considerable advertizing space and time in black newspapers and. magazines. Black... ENVIRONMENTALISM AND THE POLITICS OF EQUITY: EMERGENT TRENDS IN THE BLACK COMMUNITY· Robert Bullard University oj Tennessee-Knoxville Beverly Hendrix Wright Universityo fNew Orleans Mid-American Review of Sociology, 1987, Vol. XII, No. 2:21-38 The environmental...

  4. Natural Cutoffs effect on Charged Rotating TeV-Scale Black Hole Thermodynamics

    E-Print Network [OSTI]

    M. J. Soleimani; N. Abbasvandi; G. Gopir; Zainol Abidin Ibrahim; Shahidan Radiman; W. A. T Wan Abdullah

    2015-10-15

    We study the thermodynamics of charged rotating black hole in large extra dimensions scenario where quantum gravity effects are taken into account. We consider the effects of minimal length, minimal momentum, and maximal momentum as natural cutoffs on the thermodynamics of charged rotating TeV-scale black holes. In this framework the effect of the angular momentum and charge on the thermodynamics of the black hole are discussed. We focus also on frame dragging and Sagnac effect of the micro black holes.

  5. Energy Distribution of a Schwarzschild Black Hole in a Magnetic Universe

    E-Print Network [OSTI]

    Irina Radinschi

    2000-10-25

    We obtain the energy distribution of a Schwarzschild black hole in a magnetic universe in the Tolman prescription.

  6. NREL's Black Silicon Increases Solar Cell Efficiency by Reducing Reflected Sunlight (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2010-11-01

    A fact sheet detailing the R&D 100 Award-winning Black Silicon Nanocatalytic Wet-Chemical Etch technology.

  7. Origins and accumulation of organic matter in expanded Albian to Santonian black shale sequences on the

    E-Print Network [OSTI]

    Gilli, Adrian

    Origins and accumulation of organic matter in expanded Albian to Santonian black shale sequences laminated, Cenoma- nian­Santonian black shale sequences contain between 2% and 15% organic carbon about the depositional conditions leading to the black shale accumulations. The low d13 Corg values

  8. Entropy bound of a charged object and electrostatic self-energy in black holes

    E-Print Network [OSTI]

    B. Linet

    1999-11-30

    Without pretending to any rigour, we find a general expression of the electrostatic self-energy in static black holes with spherical symmetry. We determine the entropy bound of a charged object by assuming the existence of thermodynamics for these black holes. By combining these two results, we show that the entropy bound does not depend on the considered black hole.

  9. Statistical Classification of Black-Capped (Poecile Atricapillus) and Mountain Chickadee (Poecile Gambeli) Call Notes

    E-Print Network [OSTI]

    Dawson, Michael

    Statistical Classification of Black-Capped (Poecile Atricapillus) and Mountain Chickadee (Poecile. Sturdy University of Alberta Both black-capped (Poecile atricapillus) and mountain chickadees (Poecile. Black-capped and mountain non-D notes were summarized as a set of 9 features and then analyzed by linear

  10. Black-capped (Poecile atricapillus) and mountain chickadee (Poecile gambeli) contact call contains species, sex, and

    E-Print Network [OSTI]

    Dawson, Michael

    Black-capped (Poecile atricapillus) and mountain chickadee (Poecile gambeli) contact call contains black-capped and mountain chickadees, is among the most frequently produced call of each species of adult allopatric and sympatric black-capped and mountain chickadees in terms of nine acoustic features

  11. Status Assessment of Laysan and Black-Footed Albatrosses, North Pacific Ocean, 19232005

    E-Print Network [OSTI]

    Schweik, Charles M.

    of Laysan and black-footed albatrosses. Photograph taken by Eric VanderWerf, Pacific Rim Conservation. #12Status Assessment of Laysan and Black-Footed Albatrosses, North Pacific Ocean, 1923­2005 Scientific;Status Assessment of Laysan and Black-Footed Albatrosses, North Pacific Ocean, 1923­2005 By Javier A

  12. Marinomonas basaltis sp. nov., a marine bacterium isolated from black sand

    E-Print Network [OSTI]

    Bae, Jin-Woo

    Marinomonas basaltis sp. nov., a marine bacterium isolated from black sand Ho-Won Chang,1 Seong black sand in Soesoggak, Jeju island, Korea. The strain, designated J63T , was oxidase- and catalase- negative, rod-shaped bacterial strain, J63T , was isolated recently from black sand from Soesoggak, Jeju

  13. Vibrio areninigrae sp. nov., a marine bacterium isolated from black sand

    E-Print Network [OSTI]

    Bae, Jin-Woo

    Vibrio areninigrae sp. nov., a marine bacterium isolated from black sand Ho-Won Chang,1 Seong Woon strain was isolated from black sand collected from Soesoggak, Jeju island, Korea. The strain, designated , was recently isolated from black sand collected from Soesoggak, Jeju island, Korea. In the present study

  14. Does black carbon and humic materials in snow and ice Supervisor: Martin D. King

    E-Print Network [OSTI]

    Royal Holloway, University of London

    ) burner technology changes the and optics properties of black carbon change. As little as 10 ng of Black carbon in snowpack is a factor of two more effective than carbon dioxide in changing global air with different black carbon and humic loadings, modeling the optical properties of the snow/ice and measuring

  15. Proposed Studentship Does black carbon and humic materials in snow and ice

    E-Print Network [OSTI]

    Royal Holloway, University of London

    ) black carbon is increasing or (b) burner technology changes the and optics properties of black carbon carbon dioxide in changing global air temperatures.2 The successful candidate will set-up and conductProposed Studentship Does black carbon and humic materials in snow and ice decay? Supervisors: Dr

  16. Black carbon in Arctic snow and its effect on surface albedo

    E-Print Network [OSTI]

    1 Black carbon in Arctic snow and its effect on surface albedo Stephen Warren, University wavelengths: ice is nearly transparent. Absorptive impurities: Black carbon (soot) Brown carbon (organics broadband albedo: 83% 71% (2) by addition of black carbon (BC) (20 ppb): 0.5% for r = 100 µm 1.6% for r

  17. DEVELOPMENT OF AN ELK SIGHTABILITY MODEL FOR THE BLACK HILLS OF SOUTH DAKOTA

    E-Print Network [OSTI]

    DEVELOPMENT OF AN ELK SIGHTABILITY MODEL FOR THE BLACK HILLS OF SOUTH DAKOTA BY EVAN C. PHILLIPS SIGHTABILITY MODEL FOR THE BLACK HILLS OF SOUTH DAKOTA Evan C. Phillips August 26, 2011 Elk (Cervus elaphus specific to the elk population that resides within the Black Hills of South Dakota. Sightability trials

  18. A FAUNISTIC SURVEY OF NATIVE BEES IN THE MISSISSIPPI BLACK BELT PRAIRIE

    E-Print Network [OSTI]

    Ray, David

    A FAUNISTIC SURVEY OF NATIVE BEES IN THE MISSISSIPPI BLACK BELT PRAIRIE SURVEY OF NATIVE BEES IN THE MISSISSIPPI BLACK BELT PRAIRIE By Beverly A. McGee Smith of Study: A FAUNISTIC SURVEY OF NATIVE BEES IN THE MISSISSIPPI BLACK BELT

  19. Black Box Design Ahmad Asi, Benjimin Chang, Mehdi Dadfarnia, Serge Kamta,

    E-Print Network [OSTI]

    Austin, Mark

    , Khan Black Box Design #12;Project Stakeholders ENES489P Black-Box Team and Advisors Military Logistics Use Case 4: Threats to System/Reliability Use Case 5: Maintenance Asi, Chang, Dadfarnia, Kamta, Khan Using the Black Box System Maintenance (has its own used case activity diagram) Data Rotator program

  20. Naturally weathered feldspar surfaces in the Navajo Sandstone aquifer, Black Mesa, Arizona: Electron microscopic characterization

    E-Print Network [OSTI]

    Zhu, Chen

    Naturally weathered feldspar surfaces in the Navajo Sandstone aquifer, Black Mesa, Arizona Abstract Naturally weathered feldspar surfaces in the Jurassic Navajo Sandstone at Black Mesa, Arizona-field dissolution rate discrepancy. At Black Mesa, feldspars in the Navajo Sandstone are dissolving at $105 times