Table 23. Domestic Crude Oil First Purchase Prices by API Gravity
U.S. Energy Information Administration (EIA) Indexed Site
Form EIA-182, "Domestic Crude Oil First Purchase Report." 23. Domestic Crude Oil First Purchase Prices by API Gravity Energy Information Administration Petroleum...
API gravity ranges of EIA-182 crude streams
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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) " ,"Click worksheet9,1,50022,3,,,,6,1,,781Title: Telephone:short version)ecTotalnerr g0@3 EarlyLiquidsAPI
,"Domestic Crude Oil First Purchase Prices by API Gravity"
U.S. Energy Information Administration (EIA) Indexed Site
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 CenterFranconia, Virginia:FAQ < RAPID Jump to:SeadovCooperativeA2. World9, 2014 International PetroleumFuelAnnual Energy* j o n p oAPI
E-Print Network 3.0 - api gravity saybolt Sample Search Results
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
papi-15 12;papi-16 papi-16 Storage Qualifier Example uniform vec3 gravity... GL Shading Language papi-1 EE 7700-1 Lecture Transparency. Formatted 11:30, 25 March 2009...
Steady periodic gravity waves with surface tension
Samuel Walsh
2009-11-06T23:59:59.000Z
In this paper we consider two-dimensional, stratified, steady water waves propagating over an impermeable flat bed and with a free surface. The motion is assumed to be driven by capillarity (that is, surface tension) on the surface and a gravitational force acting on the body of the fluid. We prove the existence of global continua of classical solutions that are periodic and traveling. This is accomplished by first constructing a 1-parameter family of laminar flow solutions, $\\mathcal{T}$, then applying bifurcation theory methods to obtain local curves of small amplitude solutions branching from $\\mathcal{T}$ at an eigenvalue of the linearized problem. Each solution curve is then continued globally by means of a degree theoretic theorem in the spirit of Rabinowitz. Finally, we complement the degree theoretic picture by proving an alternate global bifurcation theorem via the analytic continuation method of Dancer.
U.S. Energy Information Administration (EIA) Indexed Site
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 CenterFranconia,(Million Barrels) Crude Oil Reserves in Nonproducing Reservoirs U.S.WyomingExpansion 5Wellhead99.6Year Jan6 441 the75
U.S. Energy Information Administration (EIA) Indexed Site
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 CenterFranconia,(Million Barrels) Crude Oil Reserves in Nonproducing Reservoirs U.S.WyomingExpansion 5Wellhead99.6Year Jan6 441 the75 5
Annual Energy Outlook 2013 [U.S. Energy Information Administration (EIA)]
drip gas, as well as liquid hydrocarbons produced from tar sands, gil- sonite, and oil shale. Excludes topped crude oil, resid- ual oil, other unfinished oils, and liquids...
ON THE EXISTENCE OF STEADY PERIODIC CAPILLARY-GRAVITY STRATIFIED WATER WAVES
points for steady water waves. The condition which ensures the lack of stagnation points for 1991ON THE EXISTENCE OF STEADY PERIODIC CAPILLARY-GRAVITY STRATIFIED WATER WAVES DAVID HENRY AND BOGDANVASILE MATIOC Abstract. We prove the existence of small steady periodic capillary-gravity water waves
Byington, Alonzo
1964-01-01T23:59:59.000Z
TEMPERATURE ( P) Pi8ure 8 70 80 160 140 SOLUBILITY OF WATER IN JET FUELS CONCLUSION 120 100 e 80 M O 60 40 20 20 40 60 TENPERATURE ('F) Figure 9 80 100 120 22 The best equation found by the regression analysis process is: ln Sol ~ 141.... 55208 - 3804. 1721 x 10 5(AG) + 2581. 6616 x 10 (AG) + 9243. 1234 x 10 (ARO) + 7004. 9175(1/T) - 3468 F 0411 x 10 (1/T)2 where: ln ~ logarithm to base "e" (natural logarithm) Sol = water solubility, mg/liter AG = aniline-gravity constant (product...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
OSCARS and Future Tech OSCARS Standard and Open Grid Forum OSCARS Developers Community Web Browser Interface (WBUI) Web Service Interface (API) Read More... Fasterdata IPv6...
api filter press: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Websites Summary: WASEDA UNIVERSITY Press Release --IT 12 3 *1 *2 OSCAR API ver. 2.0 OSCAR API C Fortran OSCAR -- API OSCAR API ver. 2.0 API API 2012 4 25 http:...
Validation and Interactivity of Web API Documentation
Jeffrey, Alan
of APIs in the directory and shows that REST1 [3] is in the majority and is growing faster than any other validation. 1ProgrammableWeb API styles are self-reported by the API owners, and APIs reported as RESTful mayValidation and Interactivity of Web API Documentation Peter J. Danielsen and Alan Jeffrey Bell Labs
Associated particle imaging (API)
NONE
1998-05-01T23:59:59.000Z
Associated Particle Imaging (API) is an active neutron probe technique that provides a 3-D image with elemental composition of the material under interrogation, and so occupies a unique niche in the interrogation of unknown objects. The highly penetrating nature of neutrons enables API to provide detailed information about targets of interest that are hidden from view. Due to the isotropic nature of the induced reactions, radiation detectors can be set on the same side of the object as the neutron source, so that the object can be interrogated from a single side. At the heat of the system is a small generator that produces a continuous, monoenergetic flux of neutrons. By measuring the trajectory of coincident alpha particles that are produced as part of the process, the trajectory of the neutron can be inferred. Interactions between a neutron and the material in its path often produce a gamma ray whose energy is characteristic of that material. When the gamma ray is detected, its energy is measured and combined with the trajectory information to produce a 3-D image of the composition of the object being interrogated. During the course of API development, a number of improvements have been made. A new, more rugged sealed Tube Neutron Generator (STNG) has been designed and fabricated that is less susceptible to radiation damage and better able to withstand the rigors of fielding than earlier designs. A specialized high-voltage power supply for the STNG has also been designed and built. A complete package of software has been written for the tasks of system calibration, diagnostics and data acquisition and analysis. A portable system has been built and field tested, proving that API can be taken out of the lab and into real-world situations, and that its performance in the field is equal to that in the lab.
Detection of periodic signatures in the solar power spectrum. On the track of l=1 gravity modes
R. A. Garcia; S. Turck-Chieze; S. J. Jimenez-Reyes; J. Ballot; P. L. Palle; A. Eff-Darwich; S. Mathur; J. Provost
2006-11-27T23:59:59.000Z
In the present work we show robust indications of the existence of g modes in the Sun using 10 years of GOLF data. The present analysis is based on the exploitation of the collective properties of the predicted low-frequency (25 to 140 microHz) g modes: their asymptotic nature, which implies a quasi equidistant separation of their periods for a given angular degree (l). The Power Spectrum (PS) of the Power Spectrum Density (PSD), reveals a significant structure indicating the presence of features (peaks) in the PSD with near equidistant periods corresponding to l=1 modes in the range n=-4 to n=-26. The study of its statistical significance of this feature was fully undertaken and complemented with Monte Carlo simulations. This structure has a confidence level better than 99.86% not to be due to pure noise. Furthermore, a detailed study of this structure suggests that the gravity modes have a much more complex structure than the one initially expected (line-widths, magnetic splittings...). Compared to the latest solar models, the obtained results tend to favor a solar core rotating significantly faster than the rest of the radiative zone. In the framework of the Phoebus group, we have also applied the same methodology to other helioseismology instruments on board SoHO and ground based networks.
Detection of periodic signatures in the solar power spectrum. On the track of l=1 gravity modes
García, R A; Jiménez-Reyes, S J; Ballot, J; Pallé, P L; Eff-Darwich, A; Mathur, S; Provost, J
2006-01-01T23:59:59.000Z
In the present work we show robust indications of the existence of g modes in the Sun using 10 years of GOLF data. The present analysis is based on the exploitation of the collective properties of the predicted low-frequency (25 to 140 microHz) g modes: their asymptotic nature, which implies a quasi equidistant separation of their periods for a given angular degree (l). The Power Spectrum (PS) of the Power Spectrum Density (PSD), reveals a significant structure indicating the presence of features (peaks) in the PSD with near equidistant periods corresponding to l=1 modes in the range n=-4 to n=-26. The study of its statistical significance of this feature was fully undertaken and complemented with Monte Carlo simulations. This structure has a confidence level better than 99.86% not to be due to pure noise. Furthermore, a detailed study of this structure suggests that the gravity modes have a much more complex structure than the one initially expected (line-widths, magnetic splittings...). Compared to the late...
Collaboration Topics - Acceleration Hardware and APIs | National...
National Nuclear Security Administration (NNSA)
repository. Early work will focus on low-level application programming interfaces (APIs), micro-benchmarks, and mini-applications. Work in the out-years will include APIs and...
Piping by queens of Apis cerana Fabricius 1793 and Apis koschevnikovi v Buttel-Reepen 1906
Paris-Sud XI, UniversitĂ© de
Short note Piping by queens of Apis cerana Fabricius 1793 and Apis koschevnikovi v Buttel Tenom, Sabah, Malaysia (Received 1 February 1993; accepted 1 August 1994) Summary — Piping queens.39 quacks/s vs 3.0 quacks/s). queen piping / Apis cerana / Apis koschevnikovi INTRODUCTION Queen piping
API Blender: A Uniform Interface to Social Platform APIs Georges Gouriten
Senellart, Pierre
Web, API, REST, data integration 1. INTRODUCTION Interacting with platforms like Facebook, YoutubeAPI Blender: A Uniform Interface to Social Platform APIs Georges Gouriten Institut TĂ©lĂ©com; TĂ©lĂ©com one social Web platform, which implies studying the related API specifications. These are often only
Runapongsa, Kanda
! ! ! ! ! ! ! ! ! CIT 2011 2554! ! 1 #12; 2 #12; 3 #12; Facebook API/3) ! 24 #12; (1/2) ! 25 #12; (2/2) ! 26 #12; Facebook Query Language (FQL) FQL SQL FQL to Facebook 8th IEEE International Conference on Automatic Face & Gesture Recognition, 2008 (FG '08). H [10
Computer Science MAPO: Mining API Usages from
Xie, Tao
Computer Science MAPO: Mining API Usages from Open Source Repositories Tao Xie Department of Computer Science North Carolina State University, USA Jian Pei Department of Computer Science Simon Fraser University, Canada Â·http://ase.csc.ncsu.edu/ #12;Computer Science Learning API Usages is Challenging Â·org
Report 1: JISC Good APIs Management Report
Rzepa, Henry S.
Report 1: JISC Good APIs Management Report A review of good practice in the provision of machine) Document Name: good_api_JISC_report_v0.8.doc Notes: Acknowledgements UKOLN is funded by the MLA to all those who gave up time to help with the report. Vital to this work were the people who filled
The Design of a Group Key Agreement API Giuseppe Ateniese
Kim, Dae-Shik
and communication-independent API. The rest of this paper is organized as follows. We be- gin with the notationThe Design of a Group Key Agreement API Giuseppe Ateniese Computer Science Department Johns Hopkins describes a protocol suite and an API geared for securing collab- orative applications. The API is based
The JANA Calibrations and Conditions Database API
David Lawrence
2010-07-01T23:59:59.000Z
Calibrations and conditions databases can be accessed from within the JANA Event Processing framework through the API defined in its JCalibration base class. The API is designed to support everything from databases, to web services to flat files for the backend. A Web Service backend using the gSOAP toolkit has been implemented which is particularly interesting since it addresses many modern cybersecurity issues including support for SSL. The API allows constants to be retrieved through a single line of C++ code with most of the context, including the transport mechanism, being implied by the run currently being analyzed and the environment relieving developers from implementing such details.
Van Reeth, T; Aerts, C; Papics, P I; Triana, S A; Zwintz, K; Degroote, P; Debosscher, J; Bloemen, S; Schmid, V S; De Smedt, K; Fremat, Y; Fuentes, A S; Homan, W; Hrudkova, M; Karjalainen, R; Lombaert, R; Nemeth, P; Oestensen, R; Van De Steene, G; Vos, J; Raskin, G; Van Winckel, H
2015-01-01T23:59:59.000Z
Gamma Doradus stars (hereafter gamma Dor stars) are gravity-mode pulsators of spectral type A or F. Such modes probe the deep stellar interior, offering a detailed fingerprint of their structure. Four-year high-precision space-based Kepler photometry of gamma Dor stars has become available, allowing us to study these stars with unprecedented detail. We selected, analysed, and characterized a sample of 67 gamma Dor stars for which we have Kepler observations available. For all the targets in the sample we assembled high-resolution spectroscopy to confirm their F-type nature. We found fourteen binaries, among which four single-lined binaries, five double-lined binaries, two triple systems and three binaries with no detected radial velocity variations. We estimated the orbital parameters whenever possible. For the single stars and the single-lined binaries, fundamental parameter values were determined from spectroscopy. We searched for period spacing patterns in the photometric data and identified this diagnosti...
Costs of Imported Crude Oil by API Gravity
Annual Energy Outlook 2013 [U.S. Energy Information Administration (EIA)]
the acquisition date. See the Explanatory Notes section for additional detail. Sources: Energy Information Administration, Form FEA-F701-M-0, "Transfer Pricing Report," January...
Percentages of Total Imported Crude Oil by API Gravity
U.S. Energy Information Administration (EIA) Indexed Site
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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 2007 10,998 9,933 10,998 10,643 10,998through 1996)DecadeYear Jan
Landed Costs of Imported Crude by API Gravity
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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 6330 0 14343 342 328 370 396After898 7012009 2010
Domestic Crude Oil First Purchase Prices by API Gravity
Annual Energy Outlook 2013 [U.S. Energy Information Administration (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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) " ,"ClickPipelines AboutDecember 2005 (Thousand9, 2015Year109 AppendixCostsDistributed GenerationandSep-14
Landed Costs of Imported Crude by API Gravity
Annual Energy Outlook 2013 [U.S. Energy Information Administration (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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) " ,"ClickPipelines AboutDecember 2005 (Thousand9,0, 1997EnvironmentElectricityrgy81 Â§ Â¨ Â¦Liquids Reserve
Landed Costs of Imported Crude by API Gravity
Annual Energy Outlook 2013 [U.S. Energy Information Administration (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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) " ,"ClickPipelines AboutDecember 2005 (Thousand9,0, 1997EnvironmentElectricityrgy81 Â§ Â¨ Â¦Liquids Reserve
Costs of Imported Crude Oil by API Gravity
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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 633 622 56623 4623 42Year Jan Feb Mar Apr May Jun Jul
Costs of Imported Crude Oil by API Gravity
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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 633 622 56623 4623 42Year Jan Feb Mar Apr May Jun Jul
Costs of Imported Crude Oil by API Gravity
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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 633 622 56623 4623 42Year Jan Feb Mar Apr May Jun Jul
Costs of Imported Crude Oil by API Gravity
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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 633 622 56623 4623 42Year Jan Feb Mar Apr May Jun Jul
Costs of Imported Crude Oil by API Gravity
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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 633 622 56623 4623 42Year Jan Feb Mar Apr May Jun Jul
Domestic Crude Oil First Purchase Prices by API Gravity
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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 633 622 56623 4623and2,819 143,436 144,151Does2009
Percentages of Total Imported Crude Oil by API Gravity
Annual Energy Outlook 2013 [U.S. Energy Information Administration (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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) " ,"ClickPipelines AboutDecember 2005 (Thousand9,0,InformationU.S. CrudeP1. Energythe PriceSep-14 Oct-14
Baskin, D.K. (Chevron Petroleum Technology Company, La Habra, CA (United States)); Jones, R.W. (Chevron Oil Field Research Company, Encinitas, CA (United States))
1993-09-01T23:59:59.000Z
This paper discusses empirical geochemical correlations used to predict API oil gravities prior to drill-stem testing in Monterey Formation reservoirs, offshore southern California. The primary objective was to eliminate expensive well testing by identifying intervals that contain low-gravity, nonproducible oil (usually <14[degrees] API). However, the correlations proved very successful in accurately predicting (within 4[degrees]API) oil gravities that range from 5 to 35[degrees] API throughout the offshore Santa Barbara and Santa Maria areas. The primary data are weight-percent sulfur and Rock-Eval pyrolysis of bitumen chemically extracted from reservoir rock samples. In general, reservoirs that contain higher gravity, producible oil have bitumen organic sulfur contents of less than 5 wt. %, Rock-Eval bitumen, and Rock-Eval bitumen S[sub 1]/S[sub 2] ratios greater than 1.0. These data are usually supplemented with Rock-Eval pyrolysis of the reservoir rock, where whole-rock S[sub 1]/S[sub 2] ratios greater than 0.30 usually indicate associated oil gravities greater than 14[degrees] API. This analytical mix gives a multiple approach for estimating reservoir oil gravities within proposed drill-stem test (DST) intervals. Using this approach, oil gravities of more than 50 DSTs have been accurately predicted in the offshore southern California area. The technique is also useful for reevaluating API gravities in older wells where Monterey reservoirs were not the primary target. Moreover, the technique should have application elsewhere, provided the range of oil gravities are not the result of obvious biodegradation and sufficient rock and oil samples are available to establish pertinent correlations. 34 refs., 14 figs., 4 tabs.
REST Web Service Maintenance Through API Policy Enforcement
California at Santa Barbara, University of
1 REST Web Service Maintenance Through API Policy Enforcement Hiranya Jayathilaka, Chandra Krintz 100% annual growth rate [2]. These APIs increasingly employ the REST (Representational State Transfer accessible to users via web application programming interfaces (web APIs) and cloud-based deployment
Towards a Common API for Structured PeertoPeer Overlays #
and abstracted, can be added to the common APIs over time. The rest of this paper is organized as followsTowards a Common API for Structured PeerÂtoÂPeer Overlays # Frank Dabek 1 , Ben Zhao 2 , Peter an ongoing effort to define common APIs for structured peerÂtoÂpeer overlays and the key abstractions
The honey bees of Ethiopia represent a new subspecies of Apis mellifera--Apis mellifera simensis n bees endemic to the volcanic dome system of Ethiopia are described as a new subspecies, Apis mellifera this population. There is no indication for the presence of more than one subspecies of honey bee in Ethiopia
Claudia de Rham
2014-03-14T23:59:59.000Z
We review recent progress in massive gravity. We start by showing how different theories of massive gravity emerge from a higher-dimensional theory of general relativity, leading to the Dvali-Gabadadze-Porrati model, cascading gravity and ghost-free massive gravity. We then explore their theoretical and phenomenological consistency, proving the absence of Boulware-Deser ghosts and reviewing the Vainshtein mechanism and the cosmological solutions in these models. Finally we present alternative and related models of massive gravity such as new massive gravity, Lorentz-violating massive gravity and non-local massive gravity.
tagging API | OpenEI Community
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 Office of InspectorConcentrating SolarElectric Coop,SaveWhiskey Flatshydro Home Waterstructured Hometagging API Home
apis mellifera workers: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
The effect of Apis mellifera carnica Polm worker bee source for populating mating of Croatia (Received 9 December 1991; accepted 18 March 1992) Summary The influence of worker...
apis mellifera populations: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
The effect of Apis mellifera carnica Polm worker bee source for populating mating of Croatia (Received 9 December 1991; accepted 18 March 1992) Summary The influence of worker...
Harrison, Jon F.; Taylor, Orley R.
2005-02-25T23:59:59.000Z
Neotropical African honeybees (Apis mellifera scutellata), in the process of spreading throughout tropical and subtropical regions of the Americas, hybridize with and mostly replace European honeybees (primarily Apis mellifera mellifera and Apis...
E-Print Network 3.0 - api 5l grade Sample Search Results
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
High... - level needs. The Simple API for Grid Applications (SAGA 1) is a GGF standardization effort... present the SAGA effort, describe its relationship to other grid API...
Api Nova Energia Srl | Open Energy Information
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 Office of Inspector GeneralDepartmentAUDIT REPORTOpenWendeGuo Feng Bio Energy Co Ltd Jump to:SummariesApi Nova Energia
Original article Pollen sources for Apis mellifera L (Hym, Apidae)
Paris-Sud XI, UniversitĂ© de
Original article Pollen sources for Apis mellifera L (Hym, Apidae) in Surinam, based on pollen samples were taken from Apis mellife- ra hives in Surinam in order to identify pollen sources) identified the sources of pollen col- lected by stingless bees in Surinam, our study is the first to examine
Original article Effects of Nosema apis Zander on inbred New
Boyer, Edmond
Original article Effects of Nosema apis Zander on inbred New Zealand honey bees (Apis mellifera ligustica L) LA Malone HA Giacon Horticulture and Food Research Institute of New Zealand Ltd, Mt Albert Research Centre, Private Bag 92 169, Auckland, New Zealand (Received 31 May 1996; accepted 16 December 1996
Liouville gravity from Einstein gravity
D. Grumiller; R. Jackiw
2007-12-28T23:59:59.000Z
We show that Liouville gravity arises as the limit of pure Einstein gravity in 2+epsilon dimensions as epsilon goes to zero, provided Newton's constant scales with epsilon. Our procedure - spherical reduction, dualization, limit, dualizing back - passes several consistency tests: geometric properties, interactions with matter and the Bekenstein-Hawking entropy are as expected from Einstein gravity.
Detecting API Usage Obstacles: A Study of iOS and Android Developer Questions
Godfrey, Michael W.
Detecting API Usage Obstacles: A Study of iOS and Android Developer Questions Wei Wang and Michael, they often encounter obstacles in finding the correct usage of the API, let alone to employ best practices. Previous research addresses this line of questions by mining API usage patterns to induce API usage
U.S. Energy Information Administration (EIA) Indexed Site
States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 - by API gravity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 - for...
Einstein Gravity from Conformal Gravity
Juan Maldacena
2011-06-09T23:59:59.000Z
We show that that four dimensional conformal gravity plus a simple Neumann boundary condition can be used to get the semiclassical (or tree level) wavefunction of the universe of four dimensional asymptotically de-Sitter or Euclidean anti-de Sitter spacetimes. This simple Neumann boundary condition selects the Einstein solution out of the more numerous solutions of conformal gravity. It thus removes the ghosts of conformal gravity from this computation. In the case of a five dimensional pure gravity theory with a positive cosmological constant we show that the late time superhorizon tree level probability measure, $|\\Psi [ g ]|^2$, for its four dimensional spatial slices is given by the action of Euclidean four dimensional conformal gravity.
Lujan, Richard E. (Santa Fe, NM)
2001-01-01T23:59:59.000Z
A mechanical gravity brake that prevents hoisted loads within a shaft from free-falling when a loss of hoisting force occurs. A loss of hoist lifting force may occur in a number of situations, for example if a hoist cable were to break, the brakes were to fail on a winch, or the hoist mechanism itself were to fail. Under normal hoisting conditions, the gravity brake of the invention is subject to an upward lifting force from the hoist and a downward pulling force from a suspended load. If the lifting force should suddenly cease, the loss of differential forces on the gravity brake in free-fall is translated to extend a set of brakes against the walls of the shaft to stop the free fall descent of the gravity brake and attached load.
E-Print Network 3.0 - api based desktop Sample Search Results
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
A virtual desktop, iPhone app, Android app, Easy Upload... API's exposed as a Service Oriented Architecture (SOA). These back-end server API's of ... Source: Zhao, Yuxiao -...
E-Print Network 3.0 - apis mellifera scutellata Sample Search...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
-clone usurpation reproduction Apis mellifera scutellata honeybee reproduction South Africa 1. INTRODUCTION... . capensis) and African ... Source: Ratnieks, Francis -...
Temporal Analysis of API Usage Concepts Gias Uddin, Barthelemy Dagenais, and Martin P. Robillard
Robillard, Martin
Temporal Analysis of API Usage Concepts Gias Uddin, BarthÂ´elÂ´emy Dagenais, and Martin P. Robillard of a client program. We propose Temporal API Usage Pattern Mining to detect API usage patterns in terms and detect temporal usage patterns, where a pattern contains a set of concepts that were added
MAPO: Mining and Recommending API Usage Patterns Hao Zhong1,2
Xie, Tao
MAPO: Mining and Recommending API Usage Patterns Hao Zhong1,2 , Tao Xie3, , Lu Zhang1,2 , Jian Pei4 , and Hong Mei1,2, 1 Key Laboratory of High Confidence Software Technologies, Ministry of Education, China 2 an API usage mining framework and its supporting tool called MAPO (Mining API usage Pattern from Open
Web API Growing Pains: Stories from Client Developers and Their Code
Zaidman, Andy
APIs make use of REST interfaces which can be easily integrated with through a single HTTP requestWeb API Growing Pains: Stories from Client Developers and Their Code Tiago Espinha, Andy Zaidman.g.gross}@tudelft.nl Abstract--Web APIs provide a systematic and extensible approach for application-to-application interaction
A RESTful API for exchanging Materials Data in the AFLOWLIB.org consortium
Curtarolo, Stefano
A RESTful API for exchanging Materials Data in the AFLOWLIB.org consortium Richard H. Taylor1, an Application Program Interface (API) follow- ing REST principles is introduced for the AFLOWLIB.org materials through a RESTful API and a python library enabling ad-hoc ap- plications [17]. Other examples of online
A MOBILE APPLICATION ACCESSING PATIENTS' HEALTH RECORDS THROUGH A REST API
Andry, FranĂ§ois
A MOBILE APPLICATION ACCESSING PATIENTS' HEALTH RECORDS THROUGH A REST API How REST, dnicholson}@axolotl.com Keywords: Mobile Application, Health Records, RHIO, Lab Results, HL7, REST API, Web we present the motivations and technical choices for creating a REST API integrated with a mobile
RDF-REST: A Unifying Framework for Web APIs and Linked Data
Paris-Sud XI, UniversitĂ© de
RDF-REST: A Unifying Framework for Web APIs and Linked Data Pierre-Antoine Champin LIRIS of efforts to bridge the gap between web APIs and linked data. The RDF-REST framework, that we developed adopted in the RDF-REST framework, and show its benefits in the design and use of web APIs. One
Towards a Common API for Structured Peer-to-Peer Overlays
and abstracted, can be added to the common APIs over time. The rest of this paper is organized as followsTowards a Common API for Structured Peer-to-Peer Overlays Frank Dabek1 , Ben Zhao2 , Peter Druschel an ongoing effort to define common APIs for structured peer-to-peer overlays and the key abstractions
Indexing the Java API Using Source Code Homan Ma, Robert Amor, Ewan Tempero
Amor, Robert
Standard API. The rest of this paper is organised as follows. In the next section, we discuss related workIndexing the Java API Using Source Code Homan Ma, Robert Amor, Ewan Tempero Department of Computer code as the basis for the index. Keywords: Java Standard API, Software Repositories, Source Code
Computers & Graphics 29 (2005) 315 Multimedia integration into the blue-c API
Staadt, Oliver
Computers & Graphics 29 (2005) 3Â15 Multimedia integration into the blue-c API Martin Naefa In this article, we present the blue-c application programming interface (API) and discuss some of its performance characteristics. The blue-c API is a software toolkit for media-rich, collaborative, immersive virtual reality
Bigelow, Stephen
Towards Automatically Estimating Porting Effort Between Web Service APIs Hiranya Jayathilaka for a programmer to port an application from one web API to another, i.e. "porting effort". Our approach defines in this language, and a metric that facilitates ranking of porting effort for API operation pairs. We evaluate our
Original article Drone congregation of Apis cerana japonica
Boyer, Edmond
Honeybee, Wakazono-chyo 3-10, Morioka 020; 2Laboratory of Applied Entomology, Faculty of Agriculture, Iwate honeybees, Apis mellifera L, have been found at sites above open ground and often in areas of depression for DCAs remains unknown and we have no information how honeybee drones congregate at the same site
Is nonrelativistic gravity possible?
Kocharyan, A. A. [School of Mathematical Sciences, Monash University, Clayton 3800 (Australia)
2009-07-15T23:59:59.000Z
We study nonrelativistic gravity using the Hamiltonian formalism. For the dynamics of general relativity (relativistic gravity) the formalism is well known and called the Arnowitt-Deser-Misner (ADM) formalism. We show that if the lapse function is constrained correctly, then nonrelativistic gravity is described by a consistent Hamiltonian system. Surprisingly, nonrelativistic gravity can have solutions identical to relativistic gravity ones. In particular, (anti-)de Sitter black holes of Einstein gravity and IR limit of Horava gravity are locally identical.
B. L. Hu
1999-02-22T23:59:59.000Z
We give a summary of the status of current research in stochastic semiclassical gravity and suggest directions for further investigations. This theory generalizes the semiclassical Einstein equation to an Einstein-Langevin equation with a stochastic source term arising from the fluctuations of the energy-momentum tensor of quantum fields. We mention recent efforts in applying this theory to the study of black hole fluctuations and backreaction problems, linear response of hot flat space, and structure formation in inflationary cosmology. To explore the physical meaning and implications of this stochastic regime in relation to both classical and quantum gravity, we find it useful to take the view that semiclassical gravity is mesoscopic physics and that general relativity is the hydrodynamic limit of certain spacetime quantum substructures. Three basic issues - stochasticity, collectivity, correlations- and three processes - dissipation, fluctuations, decoherence- underscore the transformation from quantum micro structure and interaction to the emergence of classical macro structure and dynamics. We discuss ways to probe into the high energy activity from below and make two suggestions: via effective field theory and the correlation hierarchy. We discuss how stochastic behavior at low energy in an effective theory and how correlation noise associated with coarse-grained higher correlation functions in an interacting quantum field could carry nontrivial information about the high energy sector. Finally we describe processes deemed important at the Planck scale, including tunneling and pair creation, wave scattering in random geometry, growth of fluctuations and forms, Planck scale resonance states, and spacetime foams.
Quantum Field Theory & Gravity
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Field Theory & Gravity Quantum Field Theory & Gravity Understanding discoveries at the Energy, Intensity, and Cosmic Frontiers Get Expertise Rajan Gupta (505) 667-7664 Email...
Table 28. Percentages of Total Imported Crude Oil by API Gravity
U.S. Energy Information Administration (EIA) Indexed Site
the acquisition date. See the Explanatory Notes section for additional detail. Sources: Energy Information Administration, Form FEA-F701-M-0, "Transfer Pricing Report," January...
Table 27. Landed Costs of Imported Crude Oil by API Gravity
Gasoline and Diesel Fuel Update (EIA)
the acquisition date. See the Explanatory Notes section for additional detail. Sources: Energy Information Administration, Form FEA-F701-M-0, "Transfer Pricing Report," January...
Table 23. Domestic Crude Oil First Purchase Prices by API Gravity
U.S. Energy Information Administration (EIA) Indexed Site
17.18 17.64 Source: Energy Information Administration, Form EIA-182, "Domestic Crude Oil First Purchase Report." Energy Information AdministrationPetroleum Marketing Annual...
Table 23. Domestic Crude Oil First Purchase Prices by API Gravity
U.S. Energy Information Administration (EIA) Indexed Site
data reported. Source: Energy Information Administration, Form EIA-182, "Domestic Crude Oil First Purchase Report." Energy Information Administration Petroleum Marketing Annual...
Table 23. Domestic Crude Oil First Purchase Prices by API Gravity
U.S. Energy Information Administration (EIA) Indexed Site
12.17 12.80 Source: Energy Information Administration, Form EIA-182, "Domestic Crude Oil First Purchase Report." Energy Information AdministrationPetroleum Marketing Annual...
Table 23. Domestic Crude Oil First Purchase Prices by API Gravity
Annual Energy Outlook 2013 [U.S. Energy Information Administration (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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) " ,"ClickPipelinesProved ReservesFeet)per Thousand Cubic Feet)5.257 272Production331998, andin33
Table 23. Domestic Crude Oil First Purchase Prices by API Gravity
Annual Energy Outlook 2013 [U.S. Energy Information Administration (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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) " ,"ClickPipelinesProved ReservesFeet)per Thousand Cubic Feet)5.257 272Production331998, andin33
Table 23. Domestic Crude Oil First Purchase Prices by API Gravity
Annual Energy Outlook 2013 [U.S. Energy Information Administration (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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) " ,"ClickPipelinesProved ReservesFeet)per Thousand Cubic Feet)5.257 272Production331998, andin33
Table 23. Domestic Crude Oil First Purchase Prices by API Gravity
Annual Energy Outlook 2013 [U.S. Energy Information Administration (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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) " ,"ClickPipelinesProved ReservesFeet)per Thousand Cubic Feet)5.257 272Production331998, andin33
Table 23. Domestic Crude Oil First Purchase Prices by API Gravity
Annual Energy Outlook 2013 [U.S. Energy Information Administration (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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) " ,"ClickPipelinesProved ReservesFeet)per Thousand Cubic Feet)5.257 272Production331998, andin33
Table 27. Landed Costs of Imported Crude Oil by API Gravity
Annual Energy Outlook 2013 [U.S. Energy Information Administration (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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) " ,"ClickPipelinesProved ReservesFeet)per Thousand Cubic Feet)5.257 272Production331998, 1994
Table 27. Landed Costs of Imported Crude Oil by API Gravity
Annual Energy Outlook 2013 [U.S. Energy Information Administration (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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) " ,"ClickPipelinesProved ReservesFeet)per Thousand Cubic Feet)5.257 272Production331998, 1994
Table 27. Landed Costs of Imported Crude Oil by API Gravity
Annual Energy Outlook 2013 [U.S. Energy Information Administration (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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) " ,"ClickPipelinesProved ReservesFeet)per Thousand Cubic Feet)5.257 272Production331998, 1994
Table 27. Landed Costs of Imported Crude Oil by API Gravity
Annual Energy Outlook 2013 [U.S. Energy Information Administration (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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) " ,"ClickPipelinesProved ReservesFeet)per Thousand Cubic Feet)5.257 272Production331998, 1994
Table 27. Landed Costs of Imported Crude Oil by API Gravity
Annual Energy Outlook 2013 [U.S. Energy Information Administration (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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) " ,"ClickPipelinesProved ReservesFeet)per Thousand Cubic Feet)5.257 272Production331998, 1994
Table 28. Percentages of Total Imported Crude Oil by API Gravity
Annual Energy Outlook 2013 [U.S. Energy Information Administration (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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) " ,"ClickPipelinesProved ReservesFeet)per Thousand Cubic Feet)5.257 272Production331998, 1994
Table 28. Percentages of Total Imported Crude Oil by API Gravity
Annual Energy Outlook 2013 [U.S. Energy Information Administration (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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) " ,"ClickPipelinesProved ReservesFeet)per Thousand Cubic Feet)5.257 272Production331998, 1994
Table 28. Percentages of Total Imported Crude Oil by API Gravity
Annual Energy Outlook 2013 [U.S. Energy Information Administration (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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) " ,"ClickPipelinesProved ReservesFeet)per Thousand Cubic Feet)5.257 272Production331998, 1994
Table 28. Percentages of Total Imported Crude Oil by API Gravity
Annual Energy Outlook 2013 [U.S. Energy Information Administration (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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) " ,"ClickPipelinesProved ReservesFeet)per Thousand Cubic Feet)5.257 272Production331998, 1994
Table 28. Percentages of Total Imported Crude Oil by API Gravity
Annual Energy Outlook 2013 [U.S. Energy Information Administration (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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) " ,"ClickPipelinesProved ReservesFeet)per Thousand Cubic Feet)5.257 272Production331998, 1994
F.O.B. Costs of Imported Crude Oil by API Gravity
Annual Energy Outlook 2013 [U.S. Energy Information Administration (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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) " ,"ClickPipelines AboutDecember 2005 (Thousand9,0, 1997Environment >7,99 Diagram 4. Weekly 4-WeekErin
F.O.B. Costs of Imported Crude Oil by API Gravity
Annual Energy Outlook 2013 [U.S. Energy Information Administration (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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) " ,"ClickPipelines AboutDecember 2005 (Thousand9,0, 1997Environment >7,99 Diagram 4. Weekly
F.O.B. Costs of Imported Crude Oil by API Gravity
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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) " ,"ClickPipelines About U.S.30Natural Gas Glossary529 633 6221,2372003of Energy2009 2010 2011 2012 2013
REDCap and DDI Exporting Data and Metadata with the API
Hoyle, Larry; Van Roekel, Ada
2013-04-03T23:59:59.000Z
Revised 2/17/2013 NADDI 2013, Hoyle & Van Roekel, REDCap and DDI 63 REDCap Events Issues • Does anything in DDI represents the scheduling of forms by events in a machine actionable way? • The element in each may indicate...REDCap and DDI Exporting Data and Metadata with the API Larry Hoyle and Ada Van Roekel Institute for Policy & Social Research University of Kansas Revised 2/17/2013 NADDI 2013, Hoyle & Van Roekel, REDCap and DDI 1 REDCap Consortium http...
Rodriguez, Carlos
Date Lot # Specific Gravity pH Leukocytes Nitrite Protein Glucose Ketone Urobilinogen BilirubinÂ®(Bilirubin): Lot # Protein (Sulfosalicylic Acid): Lot # Specific Gravity - Saline 0.85 Specific Gravity - H20 RBC AND DATA ENTRY FORMS #12;Date Lot # Specific Gravity pH Leukocytes Nitrite Protein Glucose Ketone
Rodriguez, Carlos
Date Lot # Specific Gravity pH Leukocytes Nitrite Protein Glucose Ketone Urobilinogen BilirubinÂ®(Bilirubin): Lot # Protein (Sulfosalicylic Acid): Lot # Specific Gravity - Saline 0.85 Specific Gravity - H20 # Specific Gravity pH Leukocytes Nitrite Protein Glucose Ketone Urobilinogen Bilirubin Blood / Hemoglobin HCG
E-Print Network 3.0 - aco api x80 Sample Search Results
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
API X80, B-3 ... Source: DOE Office of Energy Efficiency and Renewable Energy, Hydrogen, Fuel Cells and Infrastructure Technologies Program Collection: Energy Storage, Conversion...
E-Print Network 3.0 - apis mellifera hypopharyngeal Sample Search...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Vol. 27, No. 5, 2001 TASK-RELATED CHEMICAL ANALYSIS OF LABIAL GLAND Summary: VOLATILE SECRETION IN WORKER HONEYBEES (Apis mellifera ligustica) TAMAR KATZAV-GOZANSKY,1, VICTORIA...
OpenEI API listing | OpenEI Community
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 Office of InspectorConcentrating Solar Powerstories onFocus AreaDataBusPFAN)ChangeOnPAC Energy Jumpnorth starsAPI
U-Boot Standalone Application (Exports) API 18349 Embedded Real-Time Systems
Narasimhan, Priya
U-Boot Standalone Application (Exports) API 18Â349 Embedded Real-Time Systems 1 Introduction This document contains details on the U-Boot 1.1.4 Exports API used by standalone applications. Most of the details of this document were derived from reading the U-Boot source code relevant to the gum- stix
Data Management in the GridRPC GridRPC Data Management API
Caniou, Yves
Data Management in the GridRPC Issues Conclusion GridRPC Data Management API Implementations, Le Mahec, Nakada GridRPC DM API: Implem. and Interop. Issues (1/13) #12;Data Management in the GridRPC Issues Conclusion Goal GridRPC DM types: Reminder 1 Data Management in the GridRPC Goal GridRPC DM types
Acoustic behaviour of queens of the Sicil-ian honeybee (Apis mellifera sicula) and
Boyer, Edmond
honeybee (Apis mellifera lamarckii). Video documentation As described for other honeybee races the queensAcoustic behaviour of queens of the Sicil- ian honeybee (Apis mellifera sicula) and the Egyptian of the Sicilian and Egyptian honeybee produce the acoustical signals of tooting and quaking during the swarming
Chiral Gravity, Log Gravity and Extremal CFT
Alexander Maloney; Wei Song; Andrew Strominger
2009-03-26T23:59:59.000Z
We show that the linearization of all exact solutions of classical chiral gravity around the AdS3 vacuum have positive energy. Non-chiral and negative-energy solutions of the linearized equations are infrared divergent at second order, and so are removed from the spectrum. In other words, chirality is confined and the equations of motion have linearization instabilities. We prove that the only stationary, axially symmetric solutions of chiral gravity are BTZ black holes, which have positive energy. It is further shown that classical log gravity-- the theory with logarithmically relaxed boundary conditions --has finite asymptotic symmetry generators but is not chiral and hence may be dual at the quantum level to a logarithmic CFT. Moreover we show that log gravity contains chiral gravity within it as a decoupled charge superselection sector. We normally evaluate the Euclidean sum over geometries of chiral gravity and show that it gives precisely the holomorphic extremal CFT partition function. The modular invariance and integrality of the expansion coefficients of this partition function are consistent with the existence of an exact quantum theory of chiral gravity. We argue that the problem of quantizing chiral gravity is the holographic dual of the problem of constructing an extremal CFT, while quantizing log gravity is dual to the problem of constructing a logarithmic extremal CFT.
Chiral gravity, log gravity, and extremal CFT
Maloney, Alexander [Physics Department, McGill University, Montreal, QC H3A 2T8 (Canada); Song Wei [Key Laboratory of Frontiers in Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing, 100190 (China); Center for the Fundamental Laws of Nature Jefferson Physical Laboratory, Harvard University, Cambridge, Massachusetts 02138 (United States); Strominger, Andrew [Center for the Fundamental Laws of Nature Jefferson Physical Laboratory, Harvard University, Cambridge, Massachusetts 02138 (United States)
2010-03-15T23:59:59.000Z
We show that the linearization of all exact solutions of classical chiral gravity around the AdS{sub 3} vacuum have positive energy. Nonchiral and negative-energy solutions of the linearized equations are infrared divergent at second order, and so are removed from the spectrum. In other words, chirality is confined and the equations of motion have linearization instabilities. We prove that the only stationary, axially symmetric solutions of chiral gravity are BTZ black holes, which have positive energy. It is further shown that classical log gravity--the theory with logarithmically relaxed boundary conditions--has finite asymptotic symmetry generators but is not chiral and hence may be dual at the quantum level to a logarithmic conformal field theories (CFT). Moreover we show that log gravity contains chiral gravity within it as a decoupled charge superselection sector. We formally evaluate the Euclidean sum over geometries of chiral gravity and show that it gives precisely the holomorphic extremal CFT partition function. The modular invariance and integrality of the expansion coefficients of this partition function are consistent with the existence of an exact quantum theory of chiral gravity. We argue that the problem of quantizing chiral gravity is the holographic dual of the problem of constructing an extremal CFT, while quantizing log gravity is dual to the problem of constructing a logarithmic extremal CFT.
A RESTful API for exchanging materials data in the AFLOWLIB.org Richard H. Taylor a,b
Curtarolo, Stefano
A RESTful API for exchanging materials data in the AFLOWLIB.org consortium Richard H. Taylor a (API) following REST principles is introduced for the AFLOWLIB.org materials data repositories through a RESTful API and a python library enabling ad hoc applications [17]. Other examples of online
Towards noncommutative gravity
D. V. Vassilevich
2009-02-17T23:59:59.000Z
In this short article accessible for non-experts I discuss possible ways of constructing a non-commutative gravity paying special attention to possibilities of realizing the full diffeomorphism symmetry and to relations with 2D gravities.
Introduction to Modified Gravity: From the Cosmic Speedup Problem to Quantum Gravity Phenomenology
Gonzalo J. Olmo
2011-12-09T23:59:59.000Z
These notes represent a summary of the introductory part of a course on modified gravity delivered at several Spanish Universities (Granada, Valencia, and Valladolid), at the University of Wisconsin-Milwaukee (WI, USA), and at the Karl-Franzens Universitaet (Graz, Austria) during the period 2008-2011. We begin with a discussion of the classical Newtonian framework and how special relativity boosted the interest on new theories of gravity. Then we focus on Nordstrom's scalar theories of gravity and their influence on Einstein's theory of general relativity. We comment on the meaning of the Einstein equivalence principle and its implications for the construction of alternative theories of gravity. We present the cosmic speedup problem and how $f(R)$ theories can be constrained attending to their weak-field behavior. We conclude by showing that Palatini f(R) and f(R,Q) theories can be used to address different aspects of quantum gravity phenomenology and singularity problems.
Karim Noui
2010-03-31T23:59:59.000Z
We tackle the question of motion in Quantum Gravity: what does motion mean at the Planck scale? Although we are still far from a complete answer we consider here a toy model in which the problem can be formulated and resolved precisely. The setting of the toy model is three dimensional Euclidean gravity. Before studying the model in detail, we argue that Loop Quantum Gravity may provide a very useful approach when discussing the question of motion in Quantum Gravity.
Detecting gravity modes in the solar $^8B$ neutrino flux
Ilídio Lopes; Sylvaine Turck-Chičze
2014-08-28T23:59:59.000Z
The detection of gravity modes produced in the solar radiative zone has been a challenge in modern astrophysics for more than 30 yr and their amplitude in the core is not yet determined. In this Letter, we develop a new strategy to look for standing gravity modes through solar neutrino fluxes. We note that due to a resonance effect, the gravity modes of low degree and low order have the largest impact on the $^{8}B$ neutrino flux. The strongest effect is expected to occur for the dipole mode with radial order $2$, corresponding to periods of about 1.5 hr. These standing gravity waves produce temperature fluctuations that are amplified by a factor of 170 in the boron neutrino flux for the corresponding period, in consonance with the gravity modes. From current neutrino observations, we determine that the maximum temperature variation due to the gravity modes in the Sun's core is smaller than $5.8\\times 10^{-4}$. This study clearly shows that due to their high sensitivity to the temperature, the $^8B$ neutrino flux time series is an excellent tool to determine the properties of gravity modes in the solar core. Moreover, if gravity mode footprints are discovered in the $^{8}B$ neutrino flux, this opens a new line of research to probe the physics of the solar core as non-standing gravity waves of higher periods cannot be directly detected by helioseismology but could leave their signature on boron neutrino or on other neutrino fluxes.
Stephen Hawking Quantum Gravity
Visser, Matt
Stephen Hawking and Quantum Gravity Matt Visser Physics Department Washington University Saint Louis USA Science Saturdays 4 Nov 2000 #12; Stephen Hawking and Quantum Gravity Abstract: Through research, Stephen Hawking has captured a place in the popular imagina- tion. Quantum gravity in its various
Quantum Physics Einstein's Gravity
Visser, Matt
Quantum Physics confronts Einstein's Gravity Matt Visser Physics Department Washington University Saint Louis USA Science Saturdays 13 October 2001 #12; Quantum Physics confronts Einstein's Gravity and with Einstein's theory of gravity (the general relativity) is still the single biggest theoretical problem
Quantization of Emergent Gravity
Hyun Seok Yang
2014-12-24T23:59:59.000Z
Emergent gravity is based on a novel form of the equivalence principle known as the Darboux theorem or the Moser lemma in symplectic geometry stating that the electromagnetic force can always be eliminated by a local coordinate transformation as far as spacetime admits a symplectic structure, in other words, a microscopic spacetime becomes noncommutative (NC). If gravity emerges from U(1) gauge theory on NC spacetime, this picture of emergent gravity suggests a completely new quantization scheme where quantum gravity is defined by quantizing spacetime itself, leading to a dynamical NC spacetime. Therefore the quantization of emergent gravity is radically different from the conventional approach trying to quantize a phase space of metric fields. This approach for quantum gravity allows a background independent formulation where spacetime as well as matter fields is equally emergent from a universal vacuum of quantum gravity.
The leak resistance of 2-inch N-80 API treaded tubular connection
Weiner, Peter Douglas
1961-01-01T23:59:59.000Z
KATIONS DISCUSSION RECOMMENDED FUTURE TESTS SAMPLE CALCULATIONS TEST E@JIPMENT Page 10 10 12 23 TKE LEAK RESISTANCE OF 2-INCH N-80 API THREADED TUBULAR CONNECTION ILLUSTRATIONS Figure 1 2-INCH HJE API TUBING CONNECTION 2 KODAK CCMPARATOR 10...-UPS OF 2-INCH N-80 EUE TUBING 15 17 13 FRONTAL VIEW OF TEST TANK 14 TEST TA1K 15 PRESSURE TEST DATA SHEET 16 LONG DURATION TANK 18 19 21 22 THE LEAK RESISTANCE OF 2-INCH N-80 API ~ED TUBULAR CONNECTION INTROI3UCTION In recent years, well depths...
Einstein Gravity, Massive Gravity, Multi-Gravity and Nonlinear Realizations
Garrett Goon; Kurt Hinterbichler; Austin Joyce; Mark Trodden
2014-12-18T23:59:59.000Z
The existence of a ghost free theory of massive gravity begs for an interpretation as a Higgs phase of General Relativity. We revisit the study of massive gravity as a Higgs phase. Absent a compelling microphysical model of spontaneous symmetry breaking in gravity, we approach this problem from the viewpoint of nonlinear realizations. We employ the coset construction to search for the most restrictive symmetry breaking pattern whose low energy theory will both admit the de Rham--Gabadadze--Tolley (dRGT) potentials and nonlinearly realize every symmetry of General Relativity, thereby providing a new perspective from which to build theories of massive gravity. In addition to the known ghost-free terms, we find a novel parity violating interaction which preserves the constraint structure of the theory, but which vanishes on the normal branch of the theory. Finally, the procedure is extended to the cases of bi-gravity and multi-vielbein theories. Analogous parity violating interactions exist here, too, and may be non-trivial for certain classes of multi-metric theories.
E-Print Network 3.0 - abelhas apis mellifera Sample Search Results
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
mellifera forager on orange blossoms at our field site... - 401. Breed, M.D. and T.M. Stiller, 1992. Honey bee, Apis mellifera, nestmate discrimination... -Laurino, M., 1982....
E-Print Network 3.0 - abelha apis mellifera Sample Search Results
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
mellifera forager on orange blossoms at our field site... - 401. Breed, M.D. and T.M. Stiller, 1992. Honey bee, Apis mellifera, nestmate discrimination... -Laurino, M., 1982....
E-Print Network 3.0 - apis mellifera linnaeus Sample Search Results
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
in Sheffield, UK using colonies of Apis mellifera. Eggs aged 0-24 h were obtained from worker cells... noptres. Ann Sci Nat Zool 19:1-362 Breed MD, Stiller TM (1992) Honeybee,...
E-Print Network 3.0 - aco classe api Sample Search Results
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
classe api Page: << < 1 2 3 4 5 > >> 1 THE ACOF-RACE ALGORITHM FOR COMBINATORIAL OPTIMIZATION Summary: of the a posteriori tour obtained by ACO-1, which is taken here as a...
NSLS-II HIGH LEVEL APPLICATION INFRASTRUCTURE AND CLIENT API DESIGN
Shen, G.; Yang; L.; Shroff; K.
2011-03-28T23:59:59.000Z
The beam commissioning software framework of NSLS-II project adopts a client/server based architecture to replace the more traditional monolithic high level application approach. It is an open structure platform, and we try to provide a narrow API set for client application. With this narrow API, existing applications developed in different language under different architecture could be ported to our platform with small modification. This paper describes system infrastructure design, client API and system integration, and latest progress. As a new 3rd generation synchrotron light source with ultra low emittance, there are new requirements and challenges to control and manipulate the beam. A use case study and a theoretical analysis have been performed to clarify requirements and challenges to the high level applications (HLA) software environment. To satisfy those requirements and challenges, adequate system architecture of the software framework is critical for beam commissioning, study and operation. The existing traditional approaches are self-consistent, and monolithic. Some of them have adopted a concept of middle layer to separate low level hardware processing from numerical algorithm computing, physics modelling, data manipulating, plotting, and error handling. However, none of the existing approaches can satisfy the requirement. A new design has been proposed by introducing service oriented architecture technology. The HLA is combination of tools for accelerator physicists and operators, which is same as traditional approach. In NSLS-II, they include monitoring applications and control routines. Scripting environment is very important for the later part of HLA and both parts are designed based on a common set of APIs. Physicists and operators are users of these APIs, while control system engineers and a few accelerator physicists are the developers of these APIs. With our Client/Server mode based approach, we leave how to retrieve information to the developers of APIs and how to use them to form a physics application to the users. For example, how the channels are related to magnet and what the current real-time setting of a magnet is in physics unit are the internals of APIs. Measuring chromaticities are the users of APIs. All the users of APIs are working with magnet and instrument names in a physics unit. The low level communications in current or voltage unit are minimized. In this paper, we discussed our recent progress of our infrastructure development, and client API.
F. Henry-Couannier; A. Tilquin; C. Tao; A. Ealet
2007-10-24T23:59:59.000Z
The previous version of this article was a first attempt to confront the Dark Gravity theory to cosmological data. However, more recent developments lead to the conclusion that the cosmological principle is probably not valid in Dark Gravity so that this kind of analysis is at best very premature. A more recent and living review of the Dark Gravity theory can be found in gr-qc/0610079
Extended gravity from noncommutativity
Paolo Aschieri
2012-07-20T23:59:59.000Z
We review the first order theory of gravity (vierbein formulation) on noncommutative spacetime studied in [1, 2]. The first order formalism allows to couple the theory to fermions. This NC action is then reinterpreted (using the Seiberg-Witten map) as a gravity theory on commutative spacetime that contains terms with higher derivatives and higher powers of the curvature and depend on the noncommutativity parameter \\theta. When the noncommutativity is switched off we recover the usual gravity action coupled to fermions. The first nontrival corrections to the usual gravity action coupled to fermions are presented in a manifest Lorentz invariant form.
Felix M. Lev
2010-05-16T23:59:59.000Z
We consider a possibility that gravity is not an interaction but a manifestation of a symmetry based on a Galois field.
Dec 7, 2013 ... Gravity Train Project. Same page in Romanian, Polish, and in French. Let us drill a straight tunnel from West Lafayette, IN to Paris, France:.
Holographic superconductors from the massive gravity
Hua Bi Zeng; Jian-Pin Wu
2014-09-24T23:59:59.000Z
A holographic superconductor is constructed in the background of a massive gravity theory. In the normal state without condensation, the conductivity exhibits a Drude peak that approaches a delta function in the massless gravity limit as studied by David Vegh. In the superconducting state, besides the infinite DC conductivity, the AC conductivity has Drude behavior at low frequency followed by a power law-fall. These results are in agreement with that found earlier by Horowitz and Santos, who studied a holographic superconductor with an implicit periodic potential beyond the probe limit. The results also agree with measurements on some cuprates.
Particle Dynamics And Emergent Gravity
Amir H. Fatollahi
2008-05-08T23:59:59.000Z
The emergent gravity proposal is examined within the framework of noncommutative QED/gravity correspondence from particle dynamics point of view.
Counterterms in Lovelock Gravity
Mehdizadeh, M R; Zangeneh, M Kord
2015-01-01T23:59:59.000Z
In this paper, we introduce the counterterms that remove the non-logarithmic divergences of the action in third order Lovelock gravity. We do this by defining the cosmological constant in such a way that the asymptotic form of the metric have the same form in Lovelock and Einstein gravities. Thus, we employ the counterterms of Einstein gravity and show that the power law divergences in the action of Lovelock gravity can be removed by suitable choice of coefficients. We find that the dependence of these coefficients on the dimension in Lovelock gravity is the same as in Einstein gravity. We also introduce the finite energy-momentum tensor and employ these counterterms to calculate the finite action and mass of the black hole solutions of third order Lovelock gravity. We calculate the thermodynamic quantities and show that the entropy calculated through the use of Gibbs-Duhem relation is consistent with the obtained entropy by Wald's formula. We, also, find that in contrast to Einstein gravity in which there ex...
Selection Rules for the Nonlinear Interactions of Internal Gravity Waves and Inertia-Gravity Waves
Jiang, Chung-Hsiang
2010-01-01T23:59:59.000Z
Internal Gravity Waves . . . . . . . . . . . . . . 3.2.1 Twodimensional inertia-gravity wave physics . . . . . . . . .Three dimensional inertia-gravity wave physics . . . . . .
Probability around the Quantum Gravity. Part 1: Planar Pure Gravity
Probability around the Quantum Gravity. Part 1: Planar Pure Gravity V.A.Malyshev \\Lambda September 17, 1998 Abstract In this paper we study stochastic dynamics which leaves quantum gravity equilibrium science and biology. At the same time the paper can serve an introÂ duction to quantum gravity
Toroidal solutions in Horava Gravity
Ahmad Ghodsi
2011-02-24T23:59:59.000Z
Recently a new four-dimensional non relativistic renormalizable theory of gravity was proposed by Horava. This gravity reduces to Einstein gravity at large distances. In this paper by using the new action for gravity we present different toroidal solutions to the equations of motion. Our solutions describe the near horizon geometry with slow rotating parameter.
Zygmunt Lalak; Stefan Pokorski; Krzysztof Turzynski
2008-08-18T23:59:59.000Z
We investigate O'Raifeartaigh-type models for F-term supersymmetry breaking in gauge mediation scenarios in the presence of gravity. It is pointed out that the vacuum structure of those models is such that in metastable vacua gravity mediation contribution to scalar masses is always suppressed to the level below 1 percent, almost sufficient for avoiding FCNC problem. Close to that limit, gravitino mass can be in the range 10-100 GeV, opening several interesting possibilities for gauge mediation models, including Giudice-Masiero mechanism for mu and Bmu generation. Gravity sector can include stabilized moduli.
Yury M. Zinoviev
2012-01-17T23:59:59.000Z
The equations of the relativistic causal Newton gravity law for the planets of the solar system are studied in the approximation when the Sun rests at the coordinates origin and the planets do not iteract between each other.
Shan Gao
2011-07-16T23:59:59.000Z
It is argued that the existence of a minimum size of spacetime may imply the fundamental existence of gravity as a geometric property of spacetime described by general relativity.
Solar system constraints on R$^n$ gravity
A. F. Zakharov; A. A. Nucita; F. De Paolis; G. Ingrosso
2006-11-02T23:59:59.000Z
Recently, gravitational microlensing has been investigated in the framework of the weak field limit of fourth order gravity theory. However, solar system data (i.e. planetary periods and light bending) can be used to put strong constraints on the parameters of this class of gravity theories. We find that these parameters must be very close to those corresponding to the Newtonian limit of the theory.
Zhao, Ben Y.
, once properly under- stood and abstracted, can be added to the common APIs over time. The rest). Towards a Common API for Structured Peer-to-Peer OverlaysÂŁ Frank DabekÂ˝ Ben ZhaoÂľ Peter DruschelÂż John to define com- mon APIs for structured peer-to-peer overlays and the key abstractions that can be built
On the no-gravity limit of gravity
J. Kowalski-Glikman; M. Szczachor
2012-12-21T23:59:59.000Z
We argue that Relative Locality may arise in the no gravity $G\\rightarrow0$ limit of gravity. In this limit gravity becomes a topological field theory of the BF type that, after coupling to particles, may effectively deform its dynamics. We briefly discuss another no gravity limit with a self dual ground state as well as the topological ultra strong $G\\rightarrow\\infty$ one.
Tagged Neutron Source for API Inspection Systems with Greatly Enhanced Spatial Resolution
None
2012-06-04T23:59:59.000Z
We recently developed induced fission and transmission imaging methods with time- and directionally-tagged neutrons offer new capabilities for characterization of fissile material configurations and enhanced detection of special nuclear materials (SNM). An Advanced Associated Particle Imaging (API) generator with higher angular resolution and neutron yield than existing systems is needed to fully exploit these methods.
Adding Meaning to Facebook Microposts via a Mash-up API and Tracking Its Data Provenance
Tomkins, Andrew
Adding Meaning to Facebook Microposts via a Mash-up API and Tracking Its Data Provenance Thomas--The social networking website Facebook offers to its users a feature called "status updates" (or just "status. INTRODUCTION According to official Facebook statistics [7], the social networking website has more than 500
Water Sim 5.0 Model API Both researchers and water managers
Hall, Sharon J.
Water Sim 5.0 Model API Both researchers and water managers indicated that a different type not similar between different researchers and between different water managers. Thus it would not be possible that implements a simplified visual interface to the model is provided as an example of using the What is Water
Macroscopic quantization of gravity
M. Y. Amin
2010-01-09T23:59:59.000Z
The moon is receding from earth at an average rate of 3.8 cm/yr [6][7][9][12].This anomaly cannot be attributed to the well-known tidal exchange of angular momentum between earth and moon [8]. A secular change in the astronomical unit AU is definitely a concern, it is reportedly increasing by about 15 cm/yr [9][10], in this letter; the concept of macroscopic quantization of gravity is introduced to account for these anomalies on theoretical basis. Interestingly, it was found useful in measuring the speed of gravity! What is more interesting is the fact that this concept is based on solid well known classical physics with no modifications to any standard model. It was found that the speed of gravity cg is in the range 10^4 c < cg < 10^5 c.
Resummation of Massive Gravity
Rham, Claudia de [Department de Physique Theorique, Universite de Geneve, 24 Quai E. Ansermet, CH-1211 Geneve (Switzerland); Gabadadze, Gregory [Center for Cosmology and Particle Physics, Department of Physics, New York University, New York 10003 (United States); Tolley, Andrew J. [Department of Physics, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106 (United States)
2011-06-10T23:59:59.000Z
We construct four-dimensional covariant nonlinear theories of massive gravity which are ghost-free in the decoupling limit to all orders. These theories resume explicitly all the nonlinear terms of an effective field theory of massive gravity. We show that away from the decoupling limit the Hamiltonian constraint is maintained at least up to and including quartic order in nonlinearities, hence excluding the possibility of the Boulware-Deser ghost up to this order. We also show that the same remains true to all orders in a similar toy model.
Introduction to Loop Quantum Gravity
Simone Mercuri
2010-01-08T23:59:59.000Z
The questions I have been asked during the 5th International School on Field Theory and Gravitation, have compelled me to give an account of the premises that I consider important for a beginner's approach to Loop Quantum Gravity. After a description of some general arguments and an introduction to the canonical theory of gravity, I review the background independent approach to quantum gravity, giving only a brief survey of Loop Quantum Gravity.
5, 1102911054, 2005 Convective gravity
Paris-Sud XI, UniversitĂ© de
ACPD 5, 11029Â11054, 2005 Convective gravity waves at mid-latitudes Y. G. Choi et al. Title Page Discussions Wind-profiler observations of gravity waves produced by convection at mid-latitudes Y. G. Choi1Â11054, 2005 Convective gravity waves at mid-latitudes Y. G. Choi et al. Title Page Abstract Introduction
November 1984 Simplicial Quantum Gravity*
Hamber, Herbert W.
November 1984 Simplicial Quantum Gravity* Herbert W. Hamber Institute for Advanced Study Princeton, NJ 08540, USA ABSTRACT Quantum gravity on a lattice in a formulation due to Regge is reviewed in view of possible applications to renormalizable asymptotiÂ cally free higher derivative theories of gravity. * Les
6, 19532001, 2006 Imaging gravity
Boyer, Edmond
ACPD 6, 1953Â2001, 2006 Imaging gravity waves in lower stratospheric AMSU-A radiances S. D under a Creative Commons License. Atmospheric Chemistry and Physics Discussions Imaging gravity waves.eckermann@nrl.navy.mil) 1953 #12;ACPD 6, 1953Â2001, 2006 Imaging gravity waves in lower stratospheric AMSU-A radiances S. D
CFT, Integrable Models Liouville Gravity
Fominov, Yakov
CFT, Integrable Models And Liouville Gravity Chernogolovka 2009 Sunday June 28, 2009. Conference as one of components of their L, A pairs. #12;CFT, Integrable Models And Liouville Gravity Chernogolovka Gravity Chernogolovka, 2009 Tuesday June 30, 2009. CONFERENCE HALL 09:30Â10:10 Herman Boos (Wuppertal
Loop quantum gravity and observations
A. Barrau; J. Grain
2014-10-07T23:59:59.000Z
Quantum gravity has long been thought to be completely decoupled from experiments or observations. Although it is true that smoking guns are still missing, there are now serious hopes that quantum gravity phenomena might be tested. We review here some possible ways to observe loop quantum gravity effects either in the framework of cosmology or in astroparticle physics.
Even-dimensional topological gravity from Chern-Simons gravity
Nelson Merino; Alfredo Perez; Patricio Salgado
2009-10-08T23:59:59.000Z
It is shown that the topological action for gravity in 2n-dimensions can be obtained from the 2n+1-dimensional Chern-Simons gravity genuinely invariant under the Poincare group. The 2n-dimensional topological gravity is described by the dynamics of the boundary of a 2n+1-dimensional Chern-Simons gravity theory with suitable boundary conditions. The field $\\phi^{a}$, which is necessary to construct this type of topological gravity in even dimensions, is identified with the coset field associated with the non-linear realizations of the Poincare group ISO(d-1,1).
From Classical To Quantum Gravity: Introduction to Loop Quantum Gravity
Kristina Giesel; Hanno Sahlmann
2013-01-02T23:59:59.000Z
We present an introduction to the canonical quantization of gravity performed in loop quantum gravity, based on lectures held at the 3rd quantum geometry and quantum gravity school in Zakopane in 2011. A special feature of this introduction is the inclusion of new proposals for coupling matter to gravity that can be used to deparametrize the theory, thus making its dynamics more tractable. The classical and quantum aspects of these new proposals are explained alongside the standard quantization of vacuum general relativity in loop quantum gravity.
Christian Wiesendanger
2009-07-25T23:59:59.000Z
Isometrodynamics (ID), the gauge theory of the group of volume-preserving diffeomorphisms of an "inner" D-dimensional flat space, is tentatively interpreted as a fundamental theory of gravity. Dimensional analysis shows that the Planck length l_P - and through it \\hbar and \\Gamma - enters the gauge field action linking ID and gravity in a natural way. Noting that the ID gauge field couples solely through derivatives acting on "inner" space variables all ID fields are Taylor-expanded in "inner" space. Integrating out the "inner" space variables yields an effective field theory for the coefficient fields with l_P^2 emerging as the expansion parameter. For \\hbar goint to zero only the leading order field does not vanish. This classical field couples to the matter Noether currents and charges related to the translation invariance in "inner" space. A model coupling this leading order field to a matter point source is established and solved. Interpreting the matter Noether charge in terms of gravitational mass Newton's inverse square law is finally derived for a static gauge field source and a slowly moving test particle. Gravity emerges as potentially related to field variations over "inner" space and might microscopically be described by the ID gauge field or equivalently by an infinite string of coefficient fields only the leading term of which is related to the macroscopical effects of gravity.
Quantum Gravity and Turbulence
Vishnu Jejjala; Djordje Minic; Y. Jack Ng; Chia-Hsiung Tze
2010-05-18T23:59:59.000Z
We apply recent advances in quantum gravity to the problem of turbulence. Adopting the AdS/CFT approach we propose a string theory of turbulence that explains the Kolmogorov scaling in 3+1 dimensions and the Kraichnan and Kolmogorov scalings in 2+1 dimensions. In the gravitational context, turbulence is intimately related to the properties of spacetime, or quantum, foam.
Phenomenological Quantum Gravity
S. Hossenfelder
2006-11-01T23:59:59.000Z
Planck scale physics represents a future challenge, located between particle physics and general relativity. The Planck scale marks a threshold beyond which the old description of spacetime breaks down and conceptually new phenomena must appear. In the last years, increased efforts have been made to examine the phenomenology of quantum gravity, even if the full theory is still unknown.
The Origin of Structures in Generalized Gravity
J. Hwang
1997-11-21T23:59:59.000Z
In a class of generalized gravity theories with general couplings between the scalar field and the scalar curvature in the Lagrangian, we can describe the quantum generation and the classical evolution of both the scalar and tensor structures in a simple and unified manner. An accelerated expansion phase based on the generalized gravity in the early universe drives microscopic quantum fluctuations inside a causal domain to expand into macroscopic ripples in the spacetime metric on scales larger than the local horizon. Following their generation from quantum fluctuations, the ripples in the metric spend a long period outside the causal domain. During this phase their evolution is characterized by their conserved amplitudes. The evolution of these fluctuations may lead to the observed large scale structures of the universe and anisotropies in the cosmic microwave background radiation.
Fulvio Sbisa'
2014-07-09T23:59:59.000Z
The recent observational data in cosmology seem to indicate that the universe is currently expanding in an accelerated way. An intriguing interpretation of these data is that they may just be signalling that Einstein's General Relativity is not the correct description of gravity when we consider distances of the order of the present horizon of the universe. In this thesis we consider two models which modify General Relativity at very large distances, the Cascading DGP and the dRGT massive gravity, and investigate their phenomenological viability. We start with a general introduction to standard cosmology and we introduce the late time acceleration problem and the cosmological constant problem. We then provide a pedagogical introduction to the DGP model, of which the Cascading DGP is an extension, and to the dRGT massive gravity. Concerning the Cascading DGP, we show that the thin limit of the 4D brane inside the (already thin) 5D brane is well defined, at least for the class of configurations that we consider, and confirm that gravity is regularized in these set-ups. We give a geometrical interpretation of the presence of the critical tension, and comment on the difference between the results in the literature and our results, which we support with a numerical calculation. Regarding the dRGT massive gravity, we focus on the branch of solutions in which the Vainshtein mechanism can occur. We determine analytically the number and properties of local solutions which exist asymptotically on large scales (but still below the gravitational Compton wavelength), and of local (inner) solutions which exist on small scales. We characterize exactly the properties of global solutions in every point of the phase space, and characterize precisely in which regions the Vainshtein mechanism takes place. We also provide numerical solutions which confirm our analysis.
Gravity fields of eight north Pacific seamounts: implications for density
Freitag, Helen Clare
1987-01-01T23:59:59.000Z
, gravity and other geophysical data used in this study on the following seamount survey cruises; KK780807, KK800715, KK80040Z, and KK81062602 during the period from 1978 to 1981. Additional data were obtained from the National Geophysical Data Center...
Gravity, Dimension, Equilibrium, & Thermodynamics
Jerome Perez
2006-03-30T23:59:59.000Z
Is it actually possible to interpret gravitation as space's property in a pure classical way. Then, we note that extended self-gravitating system equilibrium depends directly on the number of dimension of the space in which it evolves. Given those precisions, we review the principal thermodynamical knowledge in the context of classical gravity with arbitrary dimension of space. Stability analyses for bounded 3D systems, namely the Antonov instability paradigm, are then rapproched to some amazing properties of globular clusters and galaxies.
Supplementary Data ESI-MSMS analyses. ESI-MSMS was performed on an Applied Biosystems API-
Gelb, Michael
1 Supplementary Data ESI-MSMS analyses. ESI-MSMS was performed on an Applied Biosystems API- 4000 of integrated ion peak intensities of product (IDS-P) to internal standard (IDS-IS), multiplied by the amount by the incubation time and the volume of blood (1.6 L of blood in a 2 mm DBS punch). Synthesis of IDS-S. Given below
Massive Gravity from Higher Derivative Gravity with Boundary Conditions
Minjoon Park; Lorenzo Sorbo
2012-10-29T23:59:59.000Z
With an appropriate choice of parameters, a higher derivative theory of gravity can describe a normal massive sector and a ghost massless sector. We show that, when defined on an asymptotically de Sitter spacetime with Dirichlet boundary conditions, such a higher derivative gravity can provide a framework for a unitary theory of massive gravity in four spacetime dimensions. The resulting theory is free not only of higher derivative ghosts but also of the Boulware-Deser mode.
Sbisŕ, Fulvio
2014-01-01T23:59:59.000Z
The recent observational data in cosmology seem to indicate that the universe is currently expanding in an accelerated way. An intriguing interpretation of these data is that they may just be signalling that Einstein's General Relativity is not the correct description of gravity when we consider distances of the order of the present horizon of the universe. In this thesis we consider two models which modify General Relativity at very large distances, the Cascading DGP and the dRGT massive gravity, and investigate their phenomenological viability. We start with a general introduction to standard cosmology and we introduce the late time acceleration problem and the cosmological constant problem. We then provide a pedagogical introduction to the DGP model, of which the Cascading DGP is an extension, and to the dRGT massive gravity. Concerning the Cascading DGP, we show that the thin limit of the 4D brane inside the (already thin) 5D brane is well defined, at least for the class of configurations that we consider...
Gravitational Waves from Periodic Three-Body Systems
Dmitrašinovi?, V; Hudomal, Ana
2015-01-01T23:59:59.000Z
Three bodies moving in a periodic orbit under the influence of Newtonian gravity ought to emit gravitational waves. We have calculated the gravitational radiation quadrupolar waveforms and the corresponding luminosities for the 13+11 recently discovered three-body periodic orbits in Newtonian gravity. These waves clearly allow one to distinguish between their sources: all 13+11 orbits have different waveforms and their luminosities (evaluated at the same orbit energy and body mass) vary by up to 13 orders of magnitude in the mean, and up to 20 orders of magnitude for the peak values.
Entropic Gravity in Rindler Space
Edi Halyo
2011-04-13T23:59:59.000Z
We show that Rindler horizons are entropic screens and gravity is an entropic force in Rindler space by deriving the Verlinde entropy formula from the focusing of light due to a mass close to the horizon. Consequently, gravity is also entropic in the near horizon regions of Schwarzschild and de Sitter space-times. In different limits, the entropic nature of gravity in Rindler space leads to the Bekenstein entropy bound and the uncertainty principle.
Peter West
2014-11-04T23:59:59.000Z
We consider the equation of motion in the gravity sector that arises from the non-linear realisation of the semi-direct product of E11 and its first fundamental representation, denoted by l1, in four dimensions. This equation is first order in derivatives and at low levels relates the usual field of gravity to a dual gravity field. When the generalised space-time is restricted to be the usual four dimensional space-time we show that this equation does correctly describe Einstein's theory at the linearised level. We also comment on previous discussions of dual gravity.
M. R. Setare; M. Sahraee
2014-04-22T23:59:59.000Z
In this paper we investigate the behavior of linearized gravitational excitation in the Born-Infeld Gravity in $AdS_3$ space. We obtain the linearized equation of motion and show that this higher order gravity propagate two gravitons, massless and massive, on the $AdS_3$ background. In contrast to the $R^2$ models, such as TMG or NMG, Born-Infeld Gravity does not have a critical point for any regular choice of parameters. So the logarithmic solution is not a solution of this model, due to this one can not find a logarithmic conformal field theory as a dual model for Born-Infeld Gravity.
Shan Gao
2011-07-16T23:59:59.000Z
The remarkable connections between gravity and thermodynamics seem to imply that gravity is not fundamental but emergent, and in particular, as Verlinde suggested, gravity is probably an entropic force. In this paper, we will argue that the idea of gravity as an entropic force is debatable. It is shown that there is no convincing analogy between gravity and entropic force in Verlinde's example. Neither holographic screen nor test particle satisfies all requirements for the existence of entropic force in a thermodynamics system. Furthermore, we show that the entropy increase of the screen is not caused by its statistical tendency to increase entropy as required by the existence of entropic force, but in fact caused by gravity. Therefore, Verlinde's argument for the entropic origin of gravity is problematic. In addition, we argue that the existence of a minimum size of spacetime, together with the Heisenberg uncertainty principle in quantum theory, may imply the fundamental existence of gravity as a geometric property of spacetime. This may provide a further support for the conclusion that gravity is not an entropic force.
An Underlying Theory for Gravity
Yuan K. Ha
2012-08-14T23:59:59.000Z
A new direction to understand gravity has recently been explored by considering classical gravity to be a derived interaction from an underlying theory. This underlying theory would involve new degrees of freedom at a deeper level and it would be structurally different from classical gravitation. It may conceivably be a quantum theory or a non-quantum theory. The relation between this underlying theory and Einstein's gravity is similar to the connection between statistical mechanics and thermodynamics. We discuss the apparent lack of evidence of any quantum nature of gravity in this context.
Zhao, Ben Y.
, once properly underÂ stood and abstracted, can be added to the common APIs over time. The rest). Towards a Common API for Structured PeerÂtoÂPeer Overlays #3; Frank Dabek 1 Ben Zhao 2 Peter Druschel 3 effort to define comÂ mon APIs for structured peerÂtoÂpeer overlays and the key abstractions that can
The structure of local gravity theories
Maurice J. Dupre
2014-03-12T23:59:59.000Z
We discuss the structure of local gravity theories as resulting from the idea that locally gravity must be physically characterized by tidal acceleration, and show how this relates to both Newtonian gravity and Einstein's general relativity.
The role of information in gravity
M. Spaans
2009-07-24T23:59:59.000Z
It is argued that particle-specific information on energy-momentum adjusts the strength of gravity. This form of gravity has no free parameters, preserves Einstein gravity locally and predicts 6 times stronger accelerations on galaxy scales.
Durmus A. Demir
2011-12-11T23:59:59.000Z
It is shown that, under a conformal transformation with reference to the Higgs field, the Higgs boson can be completely decoupled from electroweak interactions with no apparent change in known properties of leptons, quarks and vector bosons. Higgs boson becomes part of a scalar-tensor gravity which can be relevant for Dark Energy. It interacts with matter sector via higher-dimensional terms (e.g. neutrino Majorana mass), and via the fields (of new physics) whose masses are not generated by the Higgs mechanism. Dark Matter and two-Higgs-doublet model are the simplest examples.
Douglas Scott; Martin White
1995-05-22T23:59:59.000Z
The study of anisotropies in the Cosmic Microwave Background radiation is progressing at a phenomenal rate, both experimentally and theoretically. These anisotropies can teach us an enormous amount about the way that fluctuations were generated and the way they subsequently evolved into the clustered galaxies which are observed today. In particular, on sub-degree scales the rich structure in the anisotropy spectrum is the consequence of gravity-driven acoustic oscillations occurring before the matter in the universe became neutral. The frozen-in phases of these sound waves imprint a dependence on many cosmological parameters, that we may be on the verge of extracting.
Bergshoeff, Eric A.; Rosseel, Jan [Centre for Theoretical Physics, University of Groningen, Nijenborgh 4, 9747 AG Groningen (Netherlands); Hohm, Olaf [Center for Theoretical Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Townsend, Paul K. [Department of Applied Mathematics and Theoretical Physics, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge, CB3 0WA (United Kingdom)
2011-05-15T23:59:59.000Z
The physical modes of a recently proposed D-dimensional 'critical gravity', linearized about its anti-de Sitter vacuum, are investigated. All 'log mode' solutions, which we categorize as 'spin-2' or 'Proca', arise as limits of the massive spin-2 modes of the noncritical theory. The linearized Einstein tensor of a spin-2 log mode is itself a 'nongauge' solution of the linearized Einstein equations whereas the linearized Einstein tensor of a Proca mode takes the form of a linearized general coordinate transformation. Our results suggest the existence of a holographically dual logarithmic conformal field theory.
Ivan Dimitrijevic; Branko Dragovich; Jelena Grujic; Zoran Rakic
2012-04-09T23:59:59.000Z
We consider some aspects of nonlocal modified gravity, where nonlocality is of the type $R \\mathcal{F}(\\Box) R$. In particular, using ansatz of the form $\\Box R = c R^\\gamma,$ we find a few $R(t)$ solutions for the spatially flat FLRW metric. There are singular and nonsingular bounce solutions. For late cosmic time, scalar curvature R(t) is in low regime and scale factor a(t) is decelerated. R (t) = 0 satisfies all equations when k = -1.
Fluid Gravity Engineering Rocket motor flow analysis
Anand, Mahesh
Fluid Gravity Engineering Capability Â· Rocket motor flow analysis -Internal (performance) -External young scientists/engineers Fluid Gravity Engineering Ltd #12;
Canonical Analysis of Unimodular Gravity
J. Kluson
2014-10-07T23:59:59.000Z
This short note is devoted to the Hamiltonian analysis of the Unimodular Gravity.We treat the unimodular gravity as General Relativity action with the unimodular constraint imposed with the help of Lagrange multiplier. We perform the canonical analysis of the resulting theory and determine its constraint structure.
Reduced models for quantum gravity
T. Thiemann
1999-10-04T23:59:59.000Z
The preceding talks given at this conference have dealt mainly with general ideas for, main problems of and techniques for the task of quantizing gravity canonically. Since one of the major motivations to arrange for this meeting was that it should serve as a beginner's introduction to canonical quantum gravity, we regard it as important to demonstrate the usefulness of the formalism by means of applying it to simplified models of quantum gravity, here formulated in terms of Ashtekar's new variables. From the various, completely solvable, models that have been discussed in the literature we choose those that we consider as most suitable for our pedagogical reasons, namely 2+1 gravity and the spherically symmetric model. The former model arises from a dimensional, the latter from a Killing reduction of full 3+1 gravity. While 2+1 gravity is usually treated in terms of closed topologies without boundary of the initial data hypersurface, the toplogy for the spherically symmetric system is chosen to be asymptotically flat. Finally, 2+1 gravity is more suitably quantized using the loop representation while spherically symmetric gravity is easier to quantize via the self-dual representation. Accordingly, both types of reductions, both types of topologies and both types of representations that are mainly employed in the literature in the context of the new variables come into practice. What makes the discussion especially clear is the fact that for both models the reduced phase space turns out to be finitely dimensional.
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Storm Water Analytical Period Storm Water Analytical Period The Individual Permit authorizes the discharge of storm water associated with historical industrial activities at LANL...
Lovelock gravity from entropic force
A. Sheykhi; H. Moradpour; N. Riazi
2012-10-03T23:59:59.000Z
In this paper, we first generalize the formulation of entropic gravity to (n+1)-dimensional spacetime. Then, we propose an entropic origin for Gauss-Bonnet gravity and more general Lovelock gravity in arbitrary dimensions. As a result, we are able to derive Newton's law of gravitation as well as the corresponding Friedmann equations in these gravity theories. This procedure naturally leads to a derivation of the higher dimensional gravitational coupling constant of Friedmann/Einstein equation which is in complete agreement with the results obtained by comparing the weak field limit of Einstein equation with Poisson equation in higher dimensions. Our study shows that the approach presented here is powerful enough to derive the gravitational field equations in any gravity theory. PACS: 04.20.Cv, 04.50.-h, 04.70.Dy.
Tamara M. Rogers; Gary A. Glatzmaier
2005-08-25T23:59:59.000Z
We present numerical simulations of penetrative convection and gravity wave excitation in the Sun. Gravity waves are self-consistently generated by a convective zone overlying a radiative interior. We produce power spectra for gravity waves in the radiative region as well as estimates for the energy flux of gravity waves below the convection zone. We calculate a peak energy flux in waves below the convection zone to be three orders of magnitude smaller than previous estimates for m=1. The simulations show that the linear dispersion relation is a good approximation only deep below the convective-radiative boundary. Both low frequency propagating gravity waves as well as higher frequency standing modes are generated; although we find that convection does not continually drive the standing g-mode frequencies.
SciTech Connect: Investigating an API for resilient exascale computing.
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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administrationcontroller systemsBi (2) Sr (2) Ca (2) Cu (3)GettingGeochemicalInvestigating an API
Department of Energy Implements APIs in the Cloud | Department of Energy
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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 Delicious Rank EERE:Year in Review: TopEnergy DOEDealing WithDevelopment of NewImplements APIs in the Cloud
M. G. Romania; N. C. Tsamis; R. P. Woodard
2014-12-05T23:59:59.000Z
We review some perturbative results obtained in quantum gravity in an accelerating cosmological background. We then describe a class of non-local, purely gravitational models which have the correct structure to reproduce the leading infrared logarithms of quantum gravitational back-reaction during the inflationary regime. These models end inflation in a distinctive phase of oscillations with slight and short violations of the weak energy condition and should, when coupled to matter, lead to rapid reheating. By elaborating this class of models we exhibit one that has the same behaviour during inflation, goes quiescent until the onset of matter domination, and induces a small, positive cosmological constant of about the right size thereafter. We also briefly comment on the primordial density perturbations that this class of models predict.
Henneaux, Marc; Teitelboim, Claudio [Physique Theorique et Mathematique and International Solvay Institutes, Universite Libre de Bruxelles, Campus Plaine C. P. 231, B-1050 Brussels (Belgium) and Centro de Estudios Cientificos (CECS), Valdivia (Chile); Centro de Estudios Cientificos (CECS), Valdivia (Chile)
2005-01-15T23:59:59.000Z
We show that duality transformations of linearized gravity in four dimensions, i.e., rotations of the linearized Riemann tensor and its dual into each other, can be extended to the dynamical fields of the theory so as to be symmetries of the action and not just symmetries of the equations of motion. Our approach relies on the introduction of two superpotentials, one for the spatial components of the spin-2 field and the other for their canonically conjugate momenta. These superpotentials are two-index, symmetric tensors. They can be taken to be the basic dynamical fields and appear locally in the action. They are simply rotated into each other under duality. In terms of the superpotentials, the canonical generator of duality rotations is found to have a Chern-Simons-like structure, as in the Maxwell case.
Kay, Bernard S
2015-01-01T23:59:59.000Z
We give an account of the matter-gravity entanglement hypothesis which, unlike the standard approach to entropy based on coarse-graining, offers a definition for the entropy of a closed system as a real and objective quantity. We explain how this new approach offers an explanation for the Second Law of Thermodynamics in general and a non-paradoxical understanding of information loss during black hole formation and evaporation in particular. We also very briefly review some recent related work on the nature of equilibrium states involving quantum black holes and point out how it promises to resolve some puzzling issues in the current version of the string theory approach to black hole entropy.
Intrusive gravity currents in two-layer
Flynn, Morris R.
Intrusive gravity currents in two-layer stratified media Morris R. Flynn & Paul F. Linden Dept to as a gravity current Â· In contrast to waves, gravity currents transport significant mass (e.g. fluid parcels, sediment, insects, etc.) Introduction Gravity currents in the environment www
Riding Gravity Away from Doomsday
Sen, Ashoke
2015-01-01T23:59:59.000Z
The discovery that most of the energy density in the universe is stored in the form of dark energy has profound consequences for our future. In particular our current limited understanding of quantum theory of gravity indicates that some time in the future our universe will undergo a phase transition that will destroy us and everything else around us instantaneously. However the laws of gravity also suggest a way out -- some of our descendants could survive this catastrophe by riding gravity away from the danger. In this essay I describe the tale of this escape from doomsday.
Inversion of marine gravity data
Shih, Chung-Chi
1982-01-01T23:59:59.000Z
on the earth's gravity field and mapped the shape of the ocean surface to high accuracy (&I meter) with a horizontal resolution which averages less than 15km. Systems such as a tethered satellite attached to the Space Shuttle have been proposed to measure... for longer wavelength. The study of short wavelength isostasy requires detailed gravity and bathymetry at wavelengths of 10-50km. As the objective of this study is to infer the shape of sea floor at short wavelengths, arrays of short wavelength of gravity...
PPN-limit of Fourth Order Gravity inspired by Scalar-Tensor Gravity
S. Capozziello; A. Troisi
2005-08-01T23:59:59.000Z
Based on the {\\it dynamical} equivalence between higher order gravity and scalar-tensor gravity the PPN-limit of fourth order gravity is discussed. We exploit this analogy developing a fourth order gravity version of the Eddington PPN-parameters. As a result, Solar System experiments can be reconciled with higher order gravity, if physical constraints descending from experiments are fulfilled.
Gravity's Cosmic ShadowsGravity's Cosmic Shadows A Mathematical UnveilingA Mathematical Unveiling
Weinberger, Hans
Gravity's Cosmic ShadowsGravity's Cosmic Shadows A Mathematical UnveilingA Mathematical Unveiling of gravity on light SUNSUN #12;Gravitational Lensing - action of gravity on light SUNSUN #12;Gravitational Lensing - action of gravity on light SUNSUN nn 1801: Johann von1801: Johann von SoldnerSoldner (Newtonian
Spin-gravity coupling and gravity-induced quantum phases
Giorgio Papini
2007-09-06T23:59:59.000Z
External gravitational fields induce phase factors in the wave functions of particles. The phases are exact to first order in the background gravitational field, are manifestly covariant and gauge invariant and provide a useful tool for the study of spin-gravity coupling and of the optics of particles in gravitational or inertial fields. We discuss the role that spin-gravity coupling plays in particular problems.
Gravity Currents in Aquatic Canopies
Tanino, Yukie
A lock exchange experiment is used to investigate the propagation of gravity currents through a random array of rigid, emergent cylinders which represents a canopy of aquatic plants. As canopy drag increases, the propagating ...
Observational Tests of Modified Gravity
Bhuvnesh Jain; Pengjie Zhang
2007-09-17T23:59:59.000Z
Modified gravity theories have richer observational consequences for large-scale structure than conventional dark energy models, in that different observables are not described by a single growth factor even in the linear regime. We examine the relationships between perturbations in the metric potentials, density and velocity fields, and discuss strategies for measuring them using gravitational lensing, galaxy cluster abundances, galaxy clustering/dynamics and the ISW effect. We show how a broad class of gravity theories can be tested by combining these probes. A robust way to interpret observations is by constraining two key functions: the ratio of the two metric potentials, and the ratio of the Gravitational ``constant'' in the Poisson equation to Newton's constant. We also discuss quasilinear effects that carry signatures of gravity, such as through induced three-point correlations. Clustering of dark energy can mimic features of modified gravity theories and thus confuse the search for distinct signatures of such theories. It can produce pressure perturbations and anisotropic stresses, which breaks the equality between the two metric potentials even in general relativity. With these two extra degrees of freedom, can a clustered dark energy model mimic modified gravity models in all observational tests? We show with specific examples that observational constraints on both the metric potentials and density perturbations can in principle distinguish modifications of gravity from dark energy models. We compare our result with other recent studies that have slightly different assumptions (and apparently contradictory conclusions).
E. Gaztanaga; R. Juszkiewicz
2001-08-21T23:59:59.000Z
We present a new constraint on the biased galaxy formation picture. Gravitational instability theory predicts that the two-point mass density correlation function, \\xi(r), has an inflection point at the separation r=r_0, corresponding to the boundary between the linear and nonlinear regime of clustering, \\xi = 1. We show how this feature can be used to constrain the square of the biasing parameter, b^2 = \\xi_g / \\xi on scales r = r_0, where \\xi_g is the galaxy-galaxy correlation function, allowed to differ from \\xi. We apply our method to real data: the \\xi_g(r), estimated from the APM galaxy survey. Our results suggest that the APM galaxies trace the mass at separations r > 5 Mpc/h, where h is the Hubble constant in units of 100 km/s Mpc. The present results agree with earlier studies, based on comparing higher order correlations in the APM with weakly non-linear perturbation theory. Both approaches constrain the "b" factor to be within 20% of unity. If the existence of the feature we identified in the APM \\xi_g(r) -- the inflection point near \\xi_g = 1 -- is confirmed by more accurate surveys, we may have discovered gravity's smoking gun: the long awaited ``shoulder'' in \\xi, predicted by Gott and Rees 25 years ago.
Boyer, Edmond
How energy-efficient is your cloud app? Energy measurements in virtualized environments with PowerAPI Context Energy-efficiency major concern in data centers Existing approaches work for physical servers consumption in virtualized environments Measurements are first step towards energy-efficient data centers Host
Energy bounds in designer gravity
Amsel, Aaron J.; Marolf, Donald [Physics Department, UCSB, Santa Barbara, California 93106 (United States)
2006-09-15T23:59:59.000Z
We consider asymptotically anti-de Sitter gravity coupled to tachyonic scalar fields with mass at or slightly above the Breitenlohner-Freedman bound in d{>=}4 spacetime dimensions. The boundary conditions in these ''designer gravity'' theories are defined in terms of an arbitrary function W. We give a general argument that the Hamiltonian generators of asymptotic symmetries for such systems will be finite, and proceed to construct these generators using the covariant phase space method. The direct calculation confirms that the generators are finite and shows that they take the form of the pure gravity result plus additional contributions from the scalar fields. By comparing the generators to the spinor charge, we derive a lower bound on the gravitational energy when W has a global minimum and the Breitenlohner-Freedman bound is not saturated.
Counterterms, critical gravity and holography
Kallol Sen; Aninda Sinha; Nemani V. Suryanarayana
2012-05-18T23:59:59.000Z
We consider counterterms for odd dimensional holographic CFTs. These counterterms are derived by demanding cut-off independence of the CFT partition function on $S^d$ and $S^1 \\times S^{d-1}$. The same choice of counterterms leads to a cut-off independent Schwarzschild black hole entropy. When treated as independent actions, these counterterm actions resemble critical theories of gravity, i.e., higher curvature gravity theories where the additional massive spin-2 modes become massless. Equivalently, in the context of AdS/CFT, these are theories where at least one of the central charges associated with the trace anomaly vanishes. Connections between these theories and logarithmic CFTs are discussed. For a specific choice of parameters, the theories arising from counterterms are non-dynamical and resemble a DBI generalization of gravity. For even dimensional CFTs, analogous counterterms cancel log-independent cut-off dependence.
New Models of f(R) Theories of Gravity
J. Kluson
2009-11-04T23:59:59.000Z
We introduce new models of f(R) theories of gravity that are generalization of Horava-Lifshitz gravity.
Rapid gravity and gravity gradiometry terrain corrections via an adaptive quadtree mesh discretization Kristofer Davis1,2 M. Andy Kass1 Yaoguo Li1 1 Center for Gravity, Electrical, and Magnetic Studies of gravity gradiometry surveys utilising an adaptive quadtree mesh discretization. The data- and terrain
David Wenjie Tian; Ivan Booth
2015-03-02T23:59:59.000Z
According to Lovelock's theorem, the Hilbert-Einstein and the Lovelock actions are indistinguishable from their field equations. However, they have different scalar-tensor counterparts, which correspond to the Brans-Dicke and the \\emph{Lovelock-Brans-Dicke} (LBD) gravities, respectively. In this paper the LBD model of alternative gravity with the Lagrangian density $\\mathscr{L}_{\\text{LBD}}=\\frac{1}{16\\pi}[\\phi(R+\\frac{a}{\\sqrt{-g}}{}^*RR + b\\mathcal{G})-\\frac{\\omega_{\\text L}}{\\phi}\
Tian, David Wenjie
2015-01-01T23:59:59.000Z
According to Lovelock's theorem, the Hilbert-Einstein and the Lovelock actions are indistinguishable from their field equations. However, they have different scalar-tensor counterparts, which correspond to the Brans-Dicke and the \\emph{Lovelock-Brans-Dicke} (LBD) gravities, respectively. In this paper the LBD model of alternative gravity with the Lagrangian density $\\mathscr{L}_{\\text{LBD}}=\\frac{1}{16\\pi}\\left[\\phi\\left(R+\\frac{a}{\\sqrt{-g}}{}^*RR + b\\mathcal{G}\\right)-\\frac{\\omega_{\\text L}}{\\phi}\
Astrophysical Tests of Modified Gravity
Sakstein, Jeremy
2015-01-01T23:59:59.000Z
Chameleon and similar (symmetron and dilation) theories of gravity can exhibit new and interesting features on cosmological scales whilst screening the modifications on small scales thereby satisfying solar system tests of general relativity. This thesis explores the regime between these two scales: astrophysics. The majority of this thesis is focused on discerning new and novel astrophysical probes of chameleon gravity in the form of stellar structure and oscillation tests. These are used to place new constraints on the theory parameters and the implications of these are discussed, as are the future prospects for improving them using planned future surveys. The final two chapters review supersymmetric completions of these theories.
Variable Mass Theories of Gravity
M. Leclerc
2002-12-03T23:59:59.000Z
Several attempts to construct theories of gravity with variable mass are considered. The theoretical impacts of allowing the rest mass to vary with respect to time or an appropriate curve parameter are examined in the framework of Newtonian and Einsteinian gravity theories. In further steps, scalar-tensor theories are examined with respect to their relation to the variation of the mass and in an ultimate step, an additional coordinate is introduced and its possible relation to the mass is examined, yielding a five dimensional space-time-matter theory.
Gravity Capillary Standing Water Waves Pietro Baldi
Thomann, Laurent
Gravity Capillary Standing Water Waves Pietro Baldi Universit`a di Napoli Federico II Joint work with Thomas Alazard (ENS Paris) Pienza, 29 October 2014 Pietro Baldi Gravity Capillary Standing Water Waves, with gravity and capillarity (WW) t = G() t = -g - 1 2 2 x + (G() + xx)2 2(1 + 2 x) + xx (1 + 2 x)3/2 We
Gravity Transform for Input Conditioning in
Paiva, AntĂłnio R. C.
Gravity Transform for Input Conditioning in Brain Machine Interfaces AntĂłnio R. C. Paiva, JosĂ© C. Motivation 2. Methods i. Gravity Transform ii. Modeling and output sensitivity analysis 3. Data Analysis #12;3 Outline 1. Motivation 2. Methods i. Gravity Transform ii. Modeling and output sensitivity analysis 3. Data
Manchester, R N
2015-01-01T23:59:59.000Z
Pulsars are wonderful gravitational probes. Their tiny size and stellar mass give their rotation periods a stablility comparable to that of atomic frequency standards. This is especially true of the rapidly rotating "millisecond pulsars" (MSPs). Many of these rapidly rotating pulsars are in orbit with another star, allowing pulsar timing to probe relativistic perturbations to the orbital motion. Pulsars have provided the most stringent tests of theories of relativistic gravitation, especially in the strong-field regime, and have shown that Einstein's general theory of relativity is an accurate description of the observed motions. Many other gravitational theories are effectively ruled out or at least severely constrained by these results. MSPs can also be used to form a "Pulsar Timing Array" (PTA). PTAs are Galactic-scale interferometers that have the potential to directly detect nanohertz gravitational waves from astrophysical sources. Orbiting super-massive black holes in the cores of distant galaxies are t...
Antimatter, the SME, and Gravity
Jay D. Tasson
2012-12-07T23:59:59.000Z
A general field-theoretic framework for the analysis of CPT and Lorentz violation is provided by the Standard-Model Extension (SME). This work discusses a number of SME-based proposals for tests of CPT and Lorentz symmetry, including antihydrogen spectroscopy and antimatter gravity tests.
Antimatter, the SME, and Gravity
Tasson, Jay D
2012-01-01T23:59:59.000Z
A general field-theoretic framework for the analysis of CPT and Lorentz violation is provided by the Standard-Model Extension (SME). This work discusses a number of SME-based proposals for tests of CPT and Lorentz symmetry, including antihydrogen spectroscopy and antimatter gravity tests.
Cosmological structures in generalized gravity
J. Hwang
1997-11-28T23:59:59.000Z
In a class of generalized gravity theories with general couplings between the scalar field and the scalar curvature in the Lagrangian, we describe the quantum generation and the classical evolution processes of both the scalar and tensor structures in a simple and unified manner.
Quantum Gravity and Precision Tests
C. P. Burgess
2006-06-24T23:59:59.000Z
This article provides a cartoon of the quantization of General Relativity using the ideas of effective field theory. These ideas underpin the use of General Relativity as a theory from which precise predictions are possible, since they show why quantum corrections to standard classical calculations are small. Quantum corrections can be computed controllably provided they are made for the weakly-curved geometries associated with precision tests of General Relativity, such as within the solar system or for binary pulsars. They also bring gravity back into the mainstream of physics, by showing that its quantization (at low energies) exactly parallels the quantization of other, better understood, non-renormalizable field theories which arise elsewhere in physics. Of course effective field theory techniques do not solve the fundamental problems of quantum gravity discussed elsewhere in these pages, but they do helpfully show that these problems are specific to applications on very small distance scales. They also show why we may safely reject any proposals to modify gravity at long distances if these involve low-energy problems (like ghosts or instabilities), since such problems are unlikely to be removed by the details of the ultimate understanding of gravity at microscopic scales.
Overlap Fermion in External Gravity
Hiroto So; Masashi Hayakawa; Hiroshi Suzuki
2006-12-12T23:59:59.000Z
On a lattice, we construct an overlap Dirac operator which describes the propagation of a Dirac fermion in external gravity. The local Lorentz symmetry is manifestly realized as a lattice gauge symmetry, while the general coordinate invariance is expected to be restored only in the continuum limit. The lattice index density in the presence of a gravitational field is calculated.
Kenneth Dalton
2010-06-11T23:59:59.000Z
It is shown that gravity generates mass for the fermion. It does so by coupling directly with the spinor field. The coupling term is invariant with respect to the electroweak gauge group $ U(1) \\otimes SU(2)_L. $ It replaces the fermion mass term $ m\\bar{\\psi} \\psi $.
Perspectives on Quantum Gravity Phenomenology
Daniel Sudarsky
2005-12-01T23:59:59.000Z
The idea that quantum gravity manifestations would be associated with a violation of Lorentz invariance is very strongly bounded and faces serious theoretical challenges. Other related ideas seem to be drowning in interpretational quagmires. This leads us to consider alternative lines of thought for such phenomenological search. We discuss the underlying viewpoints and briefly mention their possible connections with other current theoretical ideas.
Thomas Rauch
2006-07-11T23:59:59.000Z
NLTE spectral analyses of high-gravity central stars by means of state-of-the-art model atmosphere techniques provide information about the precursor AGB stars. The hydrogen-deficient post-AGB stars allow investigations on the intershell matter which is apparently exhibited at the stellar surface. We summarize recent results from imaging, spectroscopy, and spectropolarimetry.
Hoffmann-Infeld Black Hole Solutions in Lovelock Gravity
Matias Aiello; Rafael Ferraro; Gaston Giribet
2005-05-19T23:59:59.000Z
Five-dimensional black holes are studied in Lovelock gravity coupled to Hoffmann-Infeld non-linear electrodynamics. It is shown that some of these solutions present a double peak behavior of the temperature as a function of the horizon radius. This feature implies that the evaporation process, though drastic for a period, leads to an eternal black hole remnant. Moreover, the form of the caloric curve corresponds to the existence of a plateau in the evaporation rate, which implies that black holes of intermediate scales turn out to be unstable. The geometrical aspects, such as the absence of conical singularity, the structure of horizons, etc. are also discussed. In particular, solutions that are asymptotically AdS arise for special choices of the parameters, corresponding to charged solutions of five-dimensional Chern-Simons gravity.
Original article Behavioural features of a periodic form of massed
Paris-Sud XI, Université de
honeybee Apis dorsata G Kastberger, O Winder, T Hoetzl, G Raspotnig Department of Neurobiology, Institute by video record- ing and image analysis. Two to three times a day the nest turns from the quiescent state / orientation flight/ image analysis/ India INTRODUCTION The Asian giant honeybee Apis dorsata Fabricius, 1798
The Dark Gravity model predictions for Gravity Probe B
Frederic Henry-Couannier
2007-10-23T23:59:59.000Z
The previous version of this article gave erroneous predictions. The correct uptodate predictions can be found in the section devoted to gravitomagnetism in the living review of the Dark Gravity theory: gr-qc/0610079 The most natural prediction is zero frame dragging and the same geodetic effect as predicted by GR. However, a straightforward extension of the theory could lead to the same frame-dragging as in GR.
Axions in gravity with torsion
Castillo-Felisola, Oscar; Kovalenko, Sergey; Schmidt, Ivan; Lyubovitskij, Valery E
2015-01-01T23:59:59.000Z
We study a scenario allowing a solution of the strong CP-problem via the Peccei-Quinn mechanism, implemented in gravity with torsion. In this framework there appears a torsion-related pseudoscalar field known as Kalb-Ramond axion. We compare it with the so called Barbero-Immirzi axion recently proposed in the literature also in the context of the gravity with torsion. We show that they are equivalent from the view point of the effective theory. The phenomenology of these torsion-descended axions is completely determined by the Planck scale without any additional model parameters. These axions are very light and very weakly interacting with ordinary matter. We briefly comment on their astrophysical and cosmological implications in view of the recent BICEP2 and Planck data.
Black holes in massive gravity
Babichev, Eugeny
2015-01-01T23:59:59.000Z
We review the black hole solutions of the ghost-free massive gravity theory and its bimetric extension and outline the main results on the stability of these solutions against small perturbations. Massive (bi)-gravity accommodates exact black hole solutions, analogous to those of General Relativity. In addition to these solutions, hairy black holes -- solutions with no correspondent in General Relativity -- have been found numerically, whose existence is a natural consequence of the absence of the Birkhoff's theorem in these theories. The existence of extra propagating degrees of freedom, makes the stability properties of these black holes richer and more complex than those of General Relativity. In particular, the bi-Schwarzschild black hole exhibits an unstable spherically symmetric mode, while the bi-Kerr geometry is also generically unstable, both against the spherical mode and against superradiant instabilities. If astrophysical black holes are described by these solutions, the superradiant instability o...
Oscillatory behavior of closed isotropic models in second order gravity theory
J. Miritzis
2008-03-11T23:59:59.000Z
Homogeneous and isotropic models are studied in the Jordan frame of the second order gravity theory. The late time evolution of the models is analysed with the methods of the dynamical systems. The normal form of the dynamical system has periodic solutions for a large set of initial conditions. This implies that an initially expanding closed isotropic universe may exhibit oscillatory behaviour.
Xavier Calmet; Priscila de Aquino
2009-10-08T23:59:59.000Z
It has recently been shown that if there is a large hidden sector in Nature, the scale of quantum gravity could be much lower than traditionally expected. We study the production of massless gravitons at the LHC and compare our results to those obtained in extra dimensional models. The signature in both cases is missing energy plus jets. In case of non observation, the LHC could be used to put the tightest limit to date on the value of the Planck mass.
Gravity Techniques | Open Energy Information
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 Office of InspectorConcentrating Solar Power BasicsGermany: Energy Resources JumpEnergyGoltryOhio: EnergyGravity
Dynamical 3-Space: Emergent Gravity
Reginald T Cahill
2011-02-16T23:59:59.000Z
The laws of gravitation devised by Newton, and by Hilbert and Einstein, have failed many experimental and observational tests, namely the bore hole g anomaly, flat rotation curves for spiral galaxies, supermassive black hole mass spectrum, uniformly expanding universe, cosmic filaments, laboratory G measurements, galactic EM bending, precocious galaxy formation,.. The response has been the introduction of the new epicycles: ``dark matter", ``dark energy", and others. To understand gravity we must restart with the experimental discoveries by Galileo, and following a heuristic argument we are led to a uniquely determined theory of a dynamical 3-space. That 3-space exists has been missed from the beginning of physics, although it was 1st directly detected by Michelson and Morley in 1887. Uniquely generalising the quantum theory to include this dynamical 3-space we deduce the response of quantum matter and show that it results in a new account of gravity, and explains the above anomalies and others. The dynamical theory for this 3-space involves G, which determines the dissipation rate of space by matter, and alpha, which experiments and observation reveal to be the fine structure constant. For the 1st time we have a comprehensive account of space and matter and their interaction - gravity.
Dynamical stability of Minkowski space in higher order gravity
Petr Tretyakov
2014-07-15T23:59:59.000Z
We discuss the Minkowski stability problem in modified gravity by using dynamical system approach. The method to investigate dynamical stability of Minkowski space was proposed. This method was applied for a some modified gravity theories, such as $f(R)$ gravity, $f(R)+\\alpha R\\Box R$ gravity and scalar-tensor gravity models with non-minimal kinetic coupling.
Entropic Motion in Loop Quantum Gravity
J. Manuel Garcia-Islas
2015-02-19T23:59:59.000Z
Entropic forces result from an increase of the entropy of a thermodynamical physical system. It has been proposed that gravity is such a phenomenon and many articles have appeared on the literature concerning this problem. Loop quantum gravity has also considered such possibility. We propose a new method in loop quantum gravity which reproduces an entropic force. By considering the interaction between a fixed gravity state space and a particle state in loop quantum gravity, we show that it leads to a mathematical description of a random walk of such particle. The random walk in special situations, can be seen as an entropic motion in such a way that the particle will move towards a location where entropy increases. This may prove that such theory can reproduce gravity as it is expected.
Born-Infeld gravity in three dimensions
Alishahiha, Mohsen [School of physics, Institute for Research in Fundamental Sciences (IPM), P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of); Naseh, Ali [School of physics, Institute for Research in Fundamental Sciences (IPM), P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of); Department of Physics, Sharif University of Technology, P.O. Box 11365-9161, Tehran (Iran, Islamic Republic of); Soltanpanahi, Hesam [School of physics, Institute for Research in Fundamental Sciences (IPM), P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of); School of Physics and Centre for Theoretical Physics, University of the Witwatersrand, WITS 2050 Johannesburg (South Africa)
2010-07-15T23:59:59.000Z
In this paper we explore different aspects of three dimensional Born-Infeld as well as Born-Infeld-Chern-Simons gravity. We show that the models have anti-de Sitter and anti-de Sitter wave vacuum solutions. Moreover, we observe that although Born-Infeld-Chern-Simons gravity admits a logarithmic solution, Born-Infeld gravity does not, though it has a limiting logarithmic solution as we approach the critical point.
Gravity from the extension of spatial diffeomorphisms
Szilard Farkas; Emil J. Martinec
2010-02-24T23:59:59.000Z
The possibility of the extension of spatial diffeomorphisms to a larger family of symmetries in a class of classical field theories is studied. The generator of the additional local symmetry contains a quadratic kinetic term and a potential term which can be a general (not necessarily local) functional of the metric. From the perspective of the foundation of Einstein's gravity our results are positive: The extended constraint algebra is either that of Einstein's gravity, or ultralocal gravity. If our goal is a simple modification of Einstein's gravity that for example makes it perturbatively renormalizable, as has recently been suggested, then our results show that there is no such theory within this class.
Cosmological Acceleration: Dark Energy or Modified Gravity?
Sidney Bludman
2006-06-12T23:59:59.000Z
We review the evidence for recently accelerating cosmological expansion or "dark energy", either a negative pressure constituent in General Relativity (Dark Energy) or modified gravity (Dark Gravity), without any Dark Energy constituent. If constituent Dark Energy does not exist, so that our universe is now dominated by pressure-free matter, Einstein gravity must be modified at low curvature. The vacuum symmetry of any Robertson-Walker universe then characterizes Dark Gravity as low- or high-curvature modifications of Einstein gravity. The dynamics of either kind of "dark energy" cannot be derived from the homogeneous expansion alone, but requires also observing the growth of inhomogeneities. Present and projected observations are all consistent with a small fine tuned cosmological constant, with nearly static Dark Energy, or with gravity modified at cosmological scales. The growth of cosmological fluctuations will potentially distinguish static "dark energy" from dynamic "dark energy" with equation of state $w(z)$ either changing rapidly or tracking the background matter. But to cosmologically distinguish $\\Lambda$CDM from modified gravity will require a weak lensing shear survey more ambitious than any now projected. Dvali-Gabadadze-Porrati modifications of Einstein gravity may also be detected in refined bservations in the solar system or at the intermediate Vainstein scale. Dark Energy's epicyclic character, failure to explain the original Cosmic Coincidence ("Why now?") without fine tuning, inaccessibility to laboratory or solar system tests, along with braneworld theories, now motivate future precision solar system, Vainstein-scale and cosmological-scale studies of Dark Gravity.
Horizon entropy with loop quantum gravity methods
Daniele Pranzetti; Hanno Sahlmann
2014-12-23T23:59:59.000Z
We show that the spherically symmetric isolated horizon can be described in terms of an SU(2) connection and a su(2) valued one form, obeying certain constraints. The horizon symplectic structure is precisely the one of 3d gravity in a first order formulation. We quantize the horizon degrees of freedom in the framework of loop quantum gravity, with methods recently developed for 3d gravity with non-vanishing cosmological constant. Bulk excitations ending on the horizon act very similar to particles in 3d gravity. The Bekenstein-Hawking law is recovered in the limit of imaginary Barbero-Immirzi parameter. Alternative methods of quantization are also discussed.
Doubly Special Relativity and quantum gravity phenomenology
J. Kowalski-Glikman
2003-12-12T23:59:59.000Z
I review the conceptual, algebraical, and geometrical structure of Doubly Special Relativity. I also speculate about the possible relevance of DSR for quantum gravity phenomenology.
Gravity modeling of Cenozoic extensional basins, offshore Vietnam
Mauri, Steven Joseph
1993-01-01T23:59:59.000Z
(Yinggehai) basins. Gravity modeling results provide important clues to the controversial tectonic development of Southeast Asia during the Tertiary. Combined Bouguer and free-air gravity maps and residual gravity anomaly maps were generated for the study...
Quantum Geometry and Quantum Gravity
J. Fernando Barbero G.
2008-04-23T23:59:59.000Z
The purpose of this contribution is to give an introduction to quantum geometry and loop quantum gravity for a wide audience of both physicists and mathematicians. From a physical point of view the emphasis will be on conceptual issues concerning the relationship of the formalism with other more traditional approaches inspired in the treatment of the fundamental interactions in the standard model. Mathematically I will pay special attention to functional analytic issues, the construction of the relevant Hilbert spaces and the definition and properties of geometric operators: areas and volumes.
Universality in Pure Gravity Mediation
Jason L. Evans; Masahiro Ibe; Keith A. Olive; Tsutomu T. Yanagida
2014-05-30T23:59:59.000Z
If low energy supersymmetry is realized in nature, the apparent discovery of a Higgs boson with mass around 125 GeV points to a supersymmetric mass spectrum in the TeV or multi-TeV range. Multi-TeV scalar masses are a necessary component of supersymmetric models with pure gravity mediation or in any model with strong moduli stabilization. Here, we show that full scalar mass universality remains viable as long as the ratio of Higgs vevs, tan beta is relatively small (\\lesssim 2.5). We discuss in detail the low energy (observable) consequences of these models.
Negative mass solitons in gravity
Cebeci, Hakan; Sarioglu, Oezguer; Tekin, Bayram [Anadolu University, Department of Physics, Yunus Emre Campus, 26470, Eskisehir (Turkey); Department of Physics, Faculty of Arts and Sciences, Middle East Technical University, 06531, Ankara (Turkey)
2006-03-15T23:59:59.000Z
We first reconstruct the conserved (Abbott-Deser) charges in the spin-connection formalism of gravity for asymptotically (Anti)-de Sitter spaces, and then compute the masses of the AdS soliton and the recently found Eguchi-Hanson solitons in generic odd dimensions, unlike the previous result obtained for only five dimensions. These solutions have negative masses compared to the global AdS or AdS/Z{sub p} spacetimes. As a separate note, we also compute the masses of the recent even dimensional Taub-NUT-Reissner-Nordstroem metrics.
Quantum Field Theory & Gravity
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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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 -the Mid-Infrared at 278, 298, and 323 K. |Quantum Field Theory & Gravity
Ground Gravity Survey At Neal Hot Springs Geothermal Area (Colwell...
Technique Ground Gravity Survey Activity Date 2011 - 2011 Usefulness not indicated DOE-funding Unknown Exploration Basis Gravity surveys were conducted to gain a better...
Integration of Full Tensor Gravity and ZTEM Passive Low Frequency...
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Integration of Full Tensor Gravity and ZTEM Passive Low Frequency EM Instruments for Simultaneous Data Acquisition Integration of Full Tensor Gravity and ZTEM Passive Low Frequency...
Reduced Gravity Education Flight Opportunity for Students at...
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airborne gravity survey: Topics by E-print Network
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Gravity CERN Preprints Summary: Modified gravity theories may provide an alternative to dark energy to explain cosmic acceleration. We argue that the observational program...
Quantum Gravity Phenomenology and Lorentz Violation
Ted Jacobson; Stefano Liberati; David Mattingly
2004-04-15T23:59:59.000Z
If quantum gravity violates Lorentz symmetry, the prospects for observational guidance in understanding quantum gravity improve considerably. This article briefly reviews previous work on Lorentz violation (LV) and discusses aspects of the effective field theory framework for parametrizing LV effects. Current observational constraints on LV are then summarized, focusing on effects in QED at order E/M_Planck.
Gravity in Complex Hermitian Space-Time
Ali H. Chamseddine
2006-10-09T23:59:59.000Z
A generalized theory unifying gravity with electromagnetism was proposed by Einstein in 1945. He considered a Hermitian metric on a real space-time. In this work we review Einstein's idea and generalize it further to consider gravity in a complex Hermitian space-time.
Fractional Exact Solutions and Solitons in Gravity
Dumitru Baleanu; Sergiu I. Vacaru
2010-08-02T23:59:59.000Z
We survay our recent results on fractional gravity theory. It is also provided the Main Theorem on encoding of geometric data (metrics and connections in gravity and geometric mechanics) into solitonic hierarchies. Our approach is based on Caputo fractional derivative and nonlinear connection formalism.
Scale-Free Growing Networks and Gravity
J. A. Nieto
2012-11-29T23:59:59.000Z
We propose a possible relation between complex networks and gravity. Our guide in our proposal is the power-law distribution of the node degree in network theory and the information approach to gravity. The established bridge may allow us to carry geometric mathematical structures, which are considered in gravitational theories, to probabilistic aspects studied in the framework of complex networks and vice versa.
The Superheavy Elements and Anti-Gravity
Anastasovski, Petar K. [Department of Physics, Faculty of Technology and Metallurgy, Saints Cyril and Methodius University, Skopje (Macedonia, The Former Yugoslav Republic of)
2004-02-04T23:59:59.000Z
The essence of any propulsion concept is to overcome gravity. Anti-gravity is a natural means to achieve this. Thus, the technology to pursue anti-gravity, by using superheavy elements, may provide a new propulsion paradigm. The theory of superluminal relativity provides a hypothesis for existence of elements with atomic number up to Z = 145, some of which may possess anti-gravity properties. Analysis results show that curved space-time exists demonstrating both gravitic and anti-gravitic properties not only around nuclei but inside the nuclei as well. Two groups of elements (Z < 64 and 63 < Z <145) exist that demonstrate these capabilities. The nuclei of the first group of elements have the masses with only the property of gravity. The nuclei of the elements of the second group have the masses with both properties: gravity and anti-gravity in two different ranges of curved space-time around the nuclei.. The hypothetical element with Z = 145 is the unique among all elements whose nucleus has only anti-gravity property. It is proposed that this element be named Hawking, in honour of Stephen W. Hawking.
Quantum Gravity Phenomenology, Lorentz Invariance and Discreteness
Sorkin, Rafael Dolnick
Quantum Gravity Phenomenology, Lorentz Invariance and Discreteness Fay Dowker #3; , Joe Henson y invariant, and we recall the reasons why. For illustration, we introduce a phenomenological model of massive { LLI violating phenomenological e#11;ects of quantum gravity { has grown up around this idea
Dual Accretion Disks in Alternate Gravity Theories
James S. Graber
1997-12-15T23:59:59.000Z
The interior of gravitationally collapsed objects in alternate theories of gravity in which event horizons and singularities do not occur in strong field gravity were generically investigated. These objects, called red holes, were found to contain dynamic configurations of matter, radiation and spacetime similar to inside out accretion disks well inside the photon orbit. Applications to astrophysical phenomena are briefly described.
Reconstruction of Einstein-Aether Gravity from other Modified Gravity Models
Chayan Ranjit; Ujjal Debnath
2014-09-08T23:59:59.000Z
We briefly describe the modified Friedmann equations for Einstein-Aether gravity theory and we find the effective density and pressure. The purpose of our present work is to reconstruction of Einstein-Aether Gravity from other modified gravities like $f(T)$, $f(R)$, $f(G)$, $f(R,T)$ and $f(R,G)$ and check its viability. The scale factor is chosen in power law form. The free function $F(K)$ for Einstein-Aether gravity (where $K$ is proportional to $H^{2}$) have been found in terms for $K$ by the correspondence between Einstein-Aether gravity and other modified gravities and the nature of $F(K)$ vs $K$ have been shown graphically for every cases. Finally, we analyzed the stability of each reconstructed Einstein-Aether gravity model.
Gravity's Rainbow induces Topology Change
Remo Garattini; Francisco S. N. Lobo
2014-08-20T23:59:59.000Z
In this work, we explore the possibility that quantum fluctuations induce a topology change, in the context of Gravity's Rainbow. A semi-classical approach is adopted, where the graviton one-loop contribution to a classical energy in a background spacetime is computed through a variational approach with Gaussian trial wave functionals. The energy density of the graviton one-loop contribution, or equivalently the background spacetime, is then let to evolve, and consequently the classical energy is determined. More specifically, the background metric is fixed to be Minkowskian in the equation governing the quantum fluctuations, which behaves essentially as a backreaction equation, and the quantum fluctuations are let to evolve; the classical energy, which depends on the evolved metric functions, is then evaluated. Analysing this procedure, a natural ultraviolet (UV) cutoff is obtained, which forbids the presence of an interior spacetime region, and may result in a multipy-connected spacetime. Thus, in the context of Gravity's Rainbow, this process may be interpreted as a change in topology, and in principle results in the presence of a Planckian wormhole.
U.S. Energy Information Administration (EIA) Indexed Site
0. Domestic Crude Oil First Purchase Prices by API Gravity (Dollars per Barrel) | | | | | | Year |...
Solar System constraints to nonminimally coupled gravity
Orfeu Bertolami; Riccardo March; Jorge Páramos
2013-06-05T23:59:59.000Z
We extend the analysis of Chiba, Smith and Erickcek \\cite{CSE} of Solar System constraints on $f(R)$ gravity to a class of nonminimally coupled (NMC) theories of gravity. These generalize $f(R)$ theories by replacing the action functional of General Relativity (GR) with a more general form involving two functions $f^1(R)$ and $f^2(R)$ of the Ricci scalar curvature $R$. While the function $f^1(R)$ is a nonlinear term in the action, analogous to $f(R)$ gravity, the function $f^2(R)$ yields a NMC between the matter Lagrangian density $\\LL_m$ and the scalar curvature. The developed method allows for obtaining constraints on the admissible classes of functions $f^1(R)$ and $f^2(R)$, by requiring that predictions of NMC gravity are compatible with Solar System tests of gravity. We apply this method to a NMC model which accounts for the observed accelerated expansion of the Universe.
Critical Collapse in Einstein-Gauss-Bonnet Gravity in Five and Six Dimensions
Deppe, N; Taves, T; Kunstatter, G; Mann, R B
2012-01-01T23:59:59.000Z
Einstein-Gauss-Bonnet gravity (EGB) provides a natural higher dimensional and higher order curvature generalization of Einstein gravity. It contains a new, presumably microscopic, length scale that should affect short distance properties of the dynamics, such as Choptuik scaling. We present the results of a numerical analysis in generalized flat slice co-ordinates of self-gravitating massless scalar spherical collapse in five and six dimensional EGB gravity near the threshold of black hole formation. Remarkably, the behaviour is universal (i.e. independent of initial data) but qualitatively different in five and six dimensions. In five dimensions there is a minimum horizon radius, suggestive of a first order transition between black hole and dispersive initial data. In six dimensions no radius gap is evident. Instead, below the GB scale there is a change in the critical exponent and echoing period.
Dimensional Reduction in Quantum Gravity
G. 't Hooft
2009-03-20T23:59:59.000Z
The requirement that physical phenomena associated with gravitational collapse should be duly reconciled with the postulates of quantum mechanics implies that at a Planckian scale our world is not 3+1 dimensional. Rather, the observable degrees of freedom can best be described as if they were Boolean variables defined on a two-dimensional lattice, evolving with time. This observation, deduced from not much more than unitarity, entropy and counting arguments, implies severe restrictions on possible models of quantum gravity. Using cellular automata as an example it is argued that this dimensional reduction implies more constraints than the freedom we have in constructing models. This is the main reason why so-far no completely consistent mathematical models of quantum black holes have been found. Essay dedicated to Abdus Salam.
Hamiltonian structure of Horava gravity
William Donnelly; Ted Jacobson
2012-01-16T23:59:59.000Z
The Hamiltonian formulation of Horava gravity is derived. In a closed universe the Hamiltonian is a sum of generators of gauge symmetries, the foliation-preserving diffeomorphisms, and vanishes on shell. The scalar constraint is second class, except for a global, first-class part that generates time reparametrizations. A reduced phase space formulation is given in which the local part of the scalar constraint is solved formally for the lapse as a function of the 3 metric and its conjugate momentum. In the infrared limit the scalar constraint is linear in the square root of the lapse. For asymptotically flat boundary conditions the Hamiltonian is a sum of bulk constraints plus a boundary term that gives the total energy. This energy expression is identical to the one for Einstein-aether theory which, for static spherically symmetric solutions, is the usual Arnowitt-Deser-Misner energy of general relativity with a rescaled Newton constant.
Nonlinear Fluid Dynamics from Gravity
Sayantani Bhattacharyya; Veronika E Hubeny; Shiraz Minwalla; Mukund Rangamani
2008-04-02T23:59:59.000Z
Black branes in AdS5 appear in a four parameter family labeled by their velocity and temperature. Promoting these parameters to Goldstone modes or collective coordinate fields -- arbitrary functions of the coordinates on the boundary of AdS5 -- we use Einstein's equations together with regularity requirements and boundary conditions to determine their dynamics. The resultant equations turn out to be those of boundary fluid dynamics, with specific values for fluid parameters. Our analysis is perturbative in the boundary derivative expansion but is valid for arbitrary amplitudes. Our work may be regarded as a derivation of the nonlinear equations of boundary fluid dynamics from gravity. As a concrete application we find an explicit expression for the expansion of this fluid stress tensor including terms up to second order in the derivative expansion.
Testing Relativistic Gravity with Radio Pulsars
Norbert Wex
2014-02-23T23:59:59.000Z
Before the 1970s, precision tests for gravity theories were constrained to the weak gravitational fields of the Solar system. Hence, only the weak-field slow-motion aspects of relativistic celestial mechanics could be investigated. Testing gravity beyond the first post-Newtonian contributions was for a long time out of reach. The discovery of the first binary pulsar by Russell Hulse and Joseph Taylor in the summer of 1974 initiated a completely new field for testing the relativistic dynamics of gravitationally interacting bodies. For the first time the back reaction of gravitational wave emission on the binary motion could be studied. Furthermore, the Hulse-Taylor pulsar provided the first test bed for the orbital dynamics of strongly self-gravitating bodies. To date there are a number of pulsars known, which can be utilized for precision test of gravity. Depending on their orbital properties and their companion, these pulsars provide tests for various different aspects of relativistic dynamics. Besides tests of specific gravity theories, like general relativity or scalar-tensor gravity, there are pulsars that allow for generic constraints on potential deviations of gravity from general relativity in the quasi-stationary strong-field and the radiative regime. This article presents a brief overview of this modern field of relativistic celestial mechanics, reviews some of the highlights of gravity tests with radio pulsars, and discusses their implications for gravitational physics and astronomy, including the upcoming gravitational wave astronomy.
Newtonian gravity, red shift, confinement, asymptotic freedom and quarks oscillations
G. Quznetsov
2008-10-18T23:59:59.000Z
Quarks oscillations give the Newtonian gravity law, the red shift, the confinement and the asymptotic freedom.
Ph.D.Thesis Binary inversion of gravity
Ph.D.Thesis Binary inversion of gravity data for salt imaging Richard A. Krahenbuhl Center for Gravity, Electrical & Magnetic Studies Colorado School of Mines Department of Geophysics Colorado School of gravity data for salt imaging Richard A. Krahenbuhl Center for Gravity, Electrical & Magnetic Studies
Gravity Recovery And Climate Experiment Hydrology, Earth Science and Climate
Mosegaard, Klaus
GRACE Gravity Recovery And Climate Experiment Hydrology, Earth Science and Climate Ole Baltazar of blood cell Delivers 10-Day / Monthly gravity field From 2002 Onwards Study gravity field changes | side 6 Range responds to Gravity #12;GRACE science results | 28. November 2007 | OA | side 7 Variations
Loop Quantum Gravity 1. Classical framework : Ashtekar-Barbero connection
Sart, Remi
gravity Why Quantum Gravity ? Gravitation vs. Quantum Physics : the two infinities Gravitation : large Quantum Gravity ? Gravitation vs. Quantum Physics : the two infinities Gravitation : large scales-perturbative renormalization Gravity is not a fundamental theory but it is effective (law energy) Â· it has to be modified
Evolution of Structures in Generalized Gravity Theories
J. Hwang
1996-05-12T23:59:59.000Z
A broad class of generalized Einstein's gravity can be cast into Einstein's gravity with a minimally coupled scalar field using suitable conformal rescaling of the metric. Using this conformal equivalence between the theories, we derive the equations for the background and the perturbations, and the general asymptotic solutions for the perturbations in the generalized Einstein's gravity from the simple results known in the minimally coupled scalar field. Results for the scalar and tensor perturbations can be presented in unified forms. The large scale evolutions for both modes are characterized by corresponding conserved quantities. We also present the normalization condition for canonical quantization.
Gravity as BF theory plus potential
Kirill Krasnov
2009-07-23T23:59:59.000Z
Spin foam models of quantum gravity are based on Plebanski's formulation of general relativity as a constrained BF theory. We give an alternative formulation of gravity as BF theory plus a certain potential term for the B-field. When the potential is taken to be infinitely steep one recovers general relativity. For a generic potential the theory still describes gravity in that it propagates just two graviton polarizations. The arising class of theories is of the type amenable to spin foam quantization methods, and, we argue, may allow one to come to terms with renormalization in the spin foam context.
Ning Wu
2012-07-11T23:59:59.000Z
When we discuss problems on gravity, we can not avoid some fundamental physical problems, such as space-time, inertia, and inertial reference frame. The goal of this paper is to discuss the logic system of gravity theory and the problems of space-time, inertia, and inertial reference frame. The goal of this paper is to set up the theory on space-time in gauge theory of gravity. Based on this theory, it is possible for human kind to manipulate physical space-time on earth, and produce a machine which can physically prolong human's lifetime.
Fractal Structure of Loop Quantum Gravity
Leonardo Modesto
2008-12-11T23:59:59.000Z
In this paper we have calculated the spectral dimension of loop quantum gravity (LQG) using simple arguments coming from the area spectrum at different length scales. We have obtained that the spectral dimension of the spatial section runs from 2 to 3, across a 1.5 phase, when the energy of a probe scalar field decrees from high to low energy. We have calculated the spectral dimension of the space-time also using results from spin-foam models, obtaining a 2-dimensional effective manifold at hight energy. Our result is consistent with other two approach to non perturbative quantum gravity: causal dynamical triangulation and asymptotic safety quantum gravity.
CDT meets Horava-Lifshitz gravity
J. Ambjorn; A. Gorlich; S. Jordan; J. Jurkiewicz; R. Loll
2010-04-06T23:59:59.000Z
The theory of causal dynamical triangulations (CDT) attempts to define a nonperturbative theory of quantum gravity as a sum over space-time geometries. One of the ingredients of the CDT framework is a global time foliation, which also plays a central role in the quantum gravity theory recently formulated by Ho\\v{r}ava. We show that the phase diagram of CDT bears a striking resemblance with the generic Lifshitz phase diagram appealed to by Ho\\v{r}ava. We argue that CDT might provide a unifying nonperturbative framework for anisotropic as well as isotropic theories of quantum gravity.
A. Miglio; J. Montalban; P. Eggenberger; A. Noels
2007-12-20T23:59:59.000Z
We investigate how the frequencies of gravity modes depend on the detailed properties of the chemical composition gradient that develops near the core of main-sequence stars and, therefore, on the transport processes that are able to modify the \\mu profile in the central regions. We show that in main-sequence models, similarly to the case of white dwarfs, the periods of high-order gravity modes are accurately described by a uniform period spacing superposed to an oscillatory component. The periodicity and amplitude of such component are related, respectively, to the location and sharpness of the \\mu gradient. We briefly discuss and interpret, by means of this simple approximation, the effect of turbulent mixing near the core on the periods of both high-order and low-order g modes, as well as of modes of mixed pressure-gravity character.
Processing gravity gradiometer data using an equivalent source technique Yaoguo Li Gravity The inherent relationship among the different components of gravity gradiometer data requires filtering operation on the constructed equivalent source. Introduction Gravity gradiometer data measure
Paris-Sud XI, UniversitĂ© de
43. Zur aktuellen Situation von Apis mel- lifera meda im Iran. K Bienefeld 1, GH Tah-K Bienefeld1, Iran; 3 Institut fĂĽr Bienenkunde, Karl-von- Frisch-Weg 2, D-61440 Oberursel, Deutsch- land) Bis zu den in Iran Up to the political changes in 1979, many queens (Midnight and Starline hybrids) were imported
Farrell, Brian F.
Gravity Waves in a Horizontal Shear Flow. Part II: Interaction between Gravity Waves and Potential perturbations and propagating internal gravity waves in a horizon- tally sheared zonal flow is investigated. In the strong stratification limit, an initial vorticity perturbation weakly excites two propagating gravity
The Branching of Graphs in 2-d Quantum Gravity
M. G. Harris
1996-07-16T23:59:59.000Z
The branching ratio is calculated for three different models of 2d gravity, using dynamical planar phi-cubed graphs. These models are pure gravity, the D=-2 Gaussian model coupled to gravity and the single spin Ising model coupled to gravity. The ratio gives a measure of how branched the graphs dominating the partition function are. Hence it can be used to estimate the location of the branched polymer phase for the multiple Ising model coupled to 2d gravity.
Antimatter-Gravity Couplings, and Lorentz Symmetry
Tasson, Jay D
2015-01-01T23:59:59.000Z
Implications of possible CPT and Lorentz violation for antimatter-gravity experiments as well as other antimatter tests are considered in the context of the general field-theory-based framework of the Standard-Model Extension (SME).
Antimatter-Gravity Couplings, and Lorentz Symmetry
Jay D. Tasson
2015-01-27T23:59:59.000Z
Implications of possible CPT and Lorentz violation for antimatter-gravity experiments as well as other antimatter tests are considered in the context of the general field-theory-based framework of the Standard-Model Extension (SME).
Test particle motion in modified gravity theories
Mahmood Roshan
2013-02-05T23:59:59.000Z
We derive the equations of motion of an electrically neutral test particle for modified gravity theories in which the covariant divergence of the ordinary matter energy-momentum tensor dose not vanish (i.e. $\
Probes of strong-field gravity
Stein, Leo Chaim
2012-01-01T23:59:59.000Z
In this thesis, I investigate several ways to probe gravity in the strong-field regime. These investigations focus on observables from the gravitational dynamics, i.e. when time derivatives are large: thus I focus on sources ...
Earthlings : humanity's essential relationship with gravity
Vargas Medina, Iris Mónica
2009-01-01T23:59:59.000Z
A realm of serious scientific questions about gravity's role in biology is being researched in labs around the world, from NASA's Dryden Research Laboratories in the Mohave Desert, to Japan's Radioisotope Center at the ...
Bounds on quantum communication via Newtonian gravity
D. Kafri; G. J. Milburn; J. M. Taylor
2014-10-08T23:59:59.000Z
Newtonian gravity yields specific observable consequences, the most striking of which is the emergence of a $1/r^2$ force. In so far as communication can arise via such interactions between distant particles, we can ask what would be expected for a theory of gravity that only allows classical communication. Many heuristic suggestions for gravity-induced decoherence have this restriction implicitly or explicitly in their construction. Here we show that communication via a $1/r^2$ force has a minimum noise induced in the system when the communication cannot convey quantum information, in a continuous time analogue to Bell's inequalities. Our derived noise bounds provide tight constraints from current experimental results on any theory of gravity that does not allow quantum communication.
Energy conditions in f(R)-gravity
J. Santos; J. S. Alcaniz; M. J. Reboucas; F. C. Carvalho
2007-09-06T23:59:59.000Z
In order to shed some light on the current discussion about f(R)-gravity theories we derive and discuss the bounds imposed by the energy conditions on a general f(R) functional form. The null and strong energy conditions in this framework are derived from the Raychaudhuri's equation along with the requirement that gravity is attractive, whereas the weak and dominant energy conditions are stated from a comparison with the energy conditions that can be obtained in a direct approach via an effective energy-momentum tensor for f(R)-gravity. As a concrete application of the energy conditions to locally homogeneous and isotropic f(R)-cosmology, the recent estimated values of the deceleration and jerk parameters are used to examine the bounds from the weak energy condition on the parameters of two families of f(R)-gravity theories.
Gravity Recovery and Interior Laboratory (GRAIL) Launch
Gravity Recovery and Interior Laboratory (GRAIL) Launch Press Kit/AUGUst 2011 #12;http of its four channels to AC-3, making each channel's secondary audio MPEG 1 Layer II. For digital downlink
Zhan, Lang; Yortsos, Yanis
2000-09-11T23:59:59.000Z
A new gravity finger model was proposed in this report in the absence of interfacial tension but in the presence of gravities. This model considered differences in density and viscosity of the two fluids. Thus, it was able to represent both stable and unstable displacements, and the finger development along either the upper or the bottom walls of a channel. This solution recovers the Saffman - Taylar solution if gravity is neglected. The results of the solution are very similar to the solutions proposed by Brener et al. for the gravity number up to 10. The solution provided in this work only has one free parameter while the solution of Brener et al. has three.
Relativistic Gravity With a Dynamical Preferred Frame
David Mattingly; Ted Jacobson
2001-12-07T23:59:59.000Z
While general relativity possesses local Lorentz invariance, both canonical quantum gravity and string theory suggest that Lorentz invariance may be broken at high energies. Broken Lorentz invariance has also been postulated as an explanation for astrophysical anomalies such as the missing GZK cutoff. Therefore, we seek an effective field theory description of gravity where Lorentz invariance is broken. We will construct a candidate theory and then briefly discuss some of the implications.
Testing Modified Gravity with Gravitational Wave Astronomy
Carlos F. Sopuerta; Nicolas Yunes
2010-10-01T23:59:59.000Z
The emergent area of gravitational wave astronomy promises to provide revolutionary discoveries in the areas of astrophysics, cosmology, and fundamental physics. One of the most exciting possibilities is to use gravitational-wave observations to test alternative theories of gravity. In this contribution we describe how to use observations of extreme-mass-ratio inspirals by the future Laser Interferometer Space Antenna to test a particular class of theories: Chern-Simons modified gravity.
2D dilaton gravity made compact
M. Navarro
1998-05-18T23:59:59.000Z
We show that the equations of motion of two-dimensional dilaton gravity conformally coupled to a scalar field can be reduced to a single non-linear second-order partial differential equation when the coordinates are chosen to coincide with the two scalar fields, the matter field $f$ and the dilaton $\\phi$, which are present in the theory. This result may help solve and understand two- and higher-dimensional classical and quantum gravity.
The shape dynamics description of gravity
Tim Koslowski
2015-01-13T23:59:59.000Z
Classical gravity can be described as a relational dynamical system without ever appealing to spacetime or its geometry. This description is the so-called shape dynamics description of gravity. The existence of relational first principles from which the shape dynamics description of gravity can be derived is a motivation to consider shape dynamics (rather than GR) as the fundamental description of gravity. Adopting this point of view leads to the question: What is the role of spacetime in the shape dynamics description of gravity? This question contains many aspects: Compatibility of shape dynamics with the description of gravity in terms of spacetime geometry, the role of local Minkowski space, universality of spacetime geometry and the nature of quantum particles, which can no longer be assumed to be irreducible representations of the Poincare group. In this contribution I derive effective spacetime structures by considering how matter fluctuations evolve along with shape dynamics. This evolution reveals an "experienced spacetime geometry." This leads (in an idealized approximation) to local Minkowski space and causal relations. The small scale structure of the emergent geometric picture depends on the specific probes used to experience spacetime, which limits the applicability of effective spacetime to describe shape dynamics. I conclude with discussing the nature of quantum fluctuations (particles) in shape dynamics and how local Minkowski spacetime emerges from the evolution of quantum particles.
A Tighter Constraint on post-Newtonian Gravity using Millisecond Pulsars
J. F. Bell
1995-08-08T23:59:59.000Z
Some theories of gravity predict the existence of preferred-frame effects and violations of conservation of energy and momentum. General relativity predicts no such effects. In the parameterised post-Newtonian (PPN) formalism, the parameter, \\al3 $\\equiv 0$ if these effects do not exist. The period derivatives ($\\dot{P}$) of millisecond pulsars (MSPs) are used to more tightly constrain these effects by showing that $|$\\al3$|$ $< 5 \\times 10^{-16}$.
Quantum gravity and inventory accumulation
Scott Sheffield
2011-08-10T23:59:59.000Z
We begin by studying inventory accumulation at a LIFO (last-in-first-out) retailer with two products. In the simplest version, the following occur with equal probability at each time step: first product ordered, first product produced, second product ordered, second product produced. The inventory thus evolves as a simple random walk on Z^2. In more interesting versions, a p fraction of customers orders the "freshest available" product regardless of type. We show that the corresponding random walks scale to Brownian motions with diffusion matrices depending on p. We then turn our attention to the critical Fortuin-Kastelyn random planar map model, which gives, for each q>0, a probability measure on random (discretized) two-dimensional surfaces decorated by loops, related to the q-state Potts model. A longstanding open problem is to show that as the discretization gets finer, the surfaces converge in law to a limiting (loop-decorated) random surface. The limit is expected to be a Liouville quantum gravity surface decorated by a conformal loop ensemble, with parameters depending on q. Thanks to a bijection between decorated planar maps and inventory trajectories (closely related to bijections of Bernardi and Mullin), our results about the latter imply convergence of the former in a particular topology. A phase transition occurs at p = 1/2, q=4.
Universality of Gravity from Entanglement
Brian Swingle; Mark Van Raamsdonk
2014-05-12T23:59:59.000Z
The entanglement "first law" in conformal field theories relates the entanglement entropy for a ball-shaped region to an integral over the same region involving the expectation value of the CFT stress-energy tensor, for infinitesimal perturbations to the CFT vacuum state. In recent work, this was exploited at leading order in $N$ in the context of large N holographic CFTs to show that any geometry dual to a perturbed CFT state must satisfy Einstein's equations linearized about pure AdS. In this note, we investigate the implications of the leading 1/N correction to the exact CFT result. We show that these corrections give rise to the source term for the gravitational equations: for semiclassical bulk states, the expectation value of the bulk stress-energy tensor appears as a source in the linearized equations. In particular, the CFT first law leads to Newton's Law of gravitation and the fact that all sources of stress-energy source the gravitational field. In our derivation, this universality of gravity comes directly from the universality of entanglement (the fact that all degrees of freedom in a subsystem contribute to entanglement entropy).
Gravitational Radiation in Noncommutative Gravity
A. Jahan; N. Sadeghnezhad
2014-11-24T23:59:59.000Z
The gravitational radiation power of a binary system in a noncommutative space is derived and it's rate of the period decrease is calculated to first order in noncommutativity parameter. By comparing the theoretical results with the observational data of the binary pulsar PSR 1913+16, we find a bound on the noncommutativity parameter.
The Role of Gravity Waves in the Formation and Organization of Clouds during TWPICE
Reeder, Michael J. [Monash University; Lane, Todd P. [University of Melbourne; Hankinson, Mai Chi Nguyen [Monash University
2013-09-27T23:59:59.000Z
All convective clouds emit gravity waves. While it is certain that convectively-generated waves play important parts in determining the climate, their precise roles remain uncertain and their effects are not (generally) represented in climate models. The work described here focuses mostly on observations and modeling of convectively-generated gravity waves, using the intensive observations from the DoE-sponsored Tropical Warm Pool International Cloud Experiment (TWP-ICE), which took place in Darwin, from 17 January to 13 February 2006. Among other things, the research has implications the part played by convectively-generated gravity waves in the formation of cirrus, in the initiation and organization of further convection, and in the subgrid-scale momentum transport and associated large-scale stresses imposed on the troposphere and stratosphere. The analysis shows two groups of inertia-gravity waves are detected: group L in the middle stratosphere during the suppressed monsoon period, and group S in the lower stratosphere during the monsoon break period. Waves belonging to group L propagate to the south-east with a mean intrinsic period of 35 h, and have vertical and horizontal wavelengths of about 5-6 km and 3000-6000 km, respectively. Ray tracing calculations indicate that these waves originate from a deep convective region near Indonesia. Waves belonging to group S propagate to the south-south-east with an intrinsic period, vertical wavelength and horizontal wavelength of about 45 h, 2 km and 2000-4000 km, respectively. These waves are shown to be associated with shallow convection in the oceanic area within about 1000 km of Darwin. The intrinsic periods of high-frequency waves are estimated to be between 20-40 minutes. The high-frequency wave activity in the stratosphere, defined by mass-weighted variance of the vertical motion of the sonde, has a maximum following the afternoon local convection indicating that these waves are generated by local convection. The wave activity is strongest in the lower stratosphere below 22 km and, during the suppressed monsoon period, is modulated with a 3-4-day period. The concentration of the wave activity in the lower stratosphere is consistent with the properties of the environment in which these waves propagate, whereas its 3-4-day modulation is explained by the variation of the convection activity in the TWP-ICE domain. At low rainfall intensity the wave activity increases as rainfall intensity increases. At high values of rainfall intensity, however, the wave activity associated with deep convective clouds is independent of the rainfall intensity. The convection and gravity waves observed during TWP-ICE are simulated with the Weather Research and Forecasting (WRF) Model. These simulations are compared with radiosonde observations described above and are used to determine some of the properties of convectively generated gravity waves. The gravity waves appear to be well simulated by the model. The model is used to explore the relationships between the convection, the gravity waves and cirrus.
Gravity and Anti-gravity of Fermions: the Unification of Dark Matter and Dark Energy
Chen, X S
2005-01-01T23:59:59.000Z
Massive gravity with second and fourth derivatives is shown to give both attractive and repulsive gravity between fermions. In contrast to the attractive gravity correlated with energy-momentum tensor, the repulsive gravity is proportional to the graviton mass. Therefore, weakly interacting fermions with energy smaller than the graviton mass are both dark matter and dark energy: Their overall gravity is attractive with normal matter but repulsive among themselves. Detailed analyses reveal that this unified dark scenario can properly account for the observed dark matter/energy phenomena: galaxy rotation curves, transition from early cosmic deceleration to recent acceleration; and naturally overcome other dark scenarios' difficulties: the substructure and cuspy core problems, the difference of dark halo distributions in galaxies and clusters, and the cosmic coincidence.
A Kinetic Theory Approach to Quantum Gravity
B. L. Hu
2002-04-22T23:59:59.000Z
We describe a kinetic theory approach to quantum gravity -- by which we mean a theory of the microscopic structure of spacetime, not a theory obtained by quantizing general relativity. A figurative conception of this program is like building a ladder with two knotted poles: quantum matter field on the right and spacetime on the left. Each rung connecting the corresponding knots represent a distinct level of structure. The lowest rung is hydrodynamics and general relativity; the next rung is semiclassical gravity, with the expectation value of quantum fields acting as source in the semiclassical Einstein equation. We recall how ideas from the statistical mechanics of interacting quantum fields helped us identify the existence of noise in the matter field and its effect on metric fluctuations, leading to the establishment of the third rung: stochastic gravity, described by the Einstein-Langevin equation. Our pathway from stochastic to quantum gravity is via the correlation hierarchy of noise and induced metric fluctuations. Three essential tasks beckon: 1) Deduce the correlations of metric fluctuations from correlation noise in the matter field; 2) Reconstituting quantum coherence -- this is the reverse of decoherence -- from these correlation functions 3) Use the Boltzmann-Langevin equations to identify distinct collective variables depicting recognizable metastable structures in the kinetic and hydrodynamic regimes of quantum matter fields and how they demand of their corresponding spacetime counterparts. This will give us a hierarchy of generalized stochastic equations -- call them the Boltzmann-Einstein hierarchy of quantum gravity -- for each level of spacetime structure, from the macroscopic (general relativity) through the mesoscopic (stochastic gravity) to the microscopic (quantum gravity).
Holographic Superconductors in Quasi-topological Gravity
Xiao-Mei Kuang; Wei-Jia Li; Yi Ling
2010-12-05T23:59:59.000Z
In this paper we study (3+1) dimensional holographic superconductors in quasi-topological gravity which is recently proposed by R. Myers {\\it et.al.}. Through both analytical and numerical analysis, we find in general the condensation becomes harder with the increase of coupling parameters of higher curvature terms. In particular, comparing with those in ordinary Gauss-Bonnet gravity, we find that positive cubic corrections in quasi-topological gravity suppress the condensation while negative cubic terms make it easier. We also calculate the conductivity numerically for various coupling parameters. It turns out that the universal relation of $\\omega_g/T_c\\simeq 8$ is unstable and this ratio becomes larger with the increase of the coupling parameters. A brief discussion on the condensation from the CFT side is also presented.
Solar system constraints on alternative gravity theories
Sumanta Chakraborty; Soumitra Sengupta
2014-01-14T23:59:59.000Z
The perihelion precession of planetary orbits and the bending angle of null geodesics are estimated for different gravity theories in string-inspired models. It is shown that, for dilaton coupled gravity, the leading order measure in the angle of bending of light comes purely from vacuum expectation value of the dilaton field which may be interpreted as an indicator of a dominant stringy effect over the curvature effect. We arrive at similar results for spherically symmetric solution in quadratic gravity. We also present the perihelion shift and bending of light in the Einstein-Maxwell-Gauss-Bonnet theory with special reference to the Casimir effect and Damour-Polyakov mechanism. Numerical bounds to different coupling parameters in these models are estimated.
Nonlinear cosmological power spectra in Einstein's gravity
Hyerim Noh; Jai-chan Hwang
2008-05-13T23:59:59.000Z
Is Newton's gravity sufficient to handle the weakly nonlinear evolution stages of the cosmic large-scale structures? Here we resolve the issue by analytically deriving the density and velocity power spectra to the second order in the context of Einstein's gravity. The recently found pure general relativistic corrections appearing in the third-order perturbation contribute to power spectra to the second order. In this work the complete density and velocity power spectra to the second order are derived. The power transfers among different scales in the density power spectrum are estimated in the context of Einstein's gravity. The relativistic corrections in the density power spectrum are estimated to be smaller than the Newtonian one to the second order, but these could be larger than higher-order nonlinear Newtonian terms.
Stable, Accelerating Universes in Modified Gravity
Simon DeDeo; Dimitrios Psaltis
2008-11-13T23:59:59.000Z
Modifications to gravity that add additional functions of the Ricci curvature to the Einstein-Hilbert action -- collectively known as $f(R)$ theories -- have been studied in great detail. When considered as complete theories of gravity they can generate non-perturbative deviations from the general relativistic predictions in the solar system, and the simplest models show instabilites on cosmological scales. Here we show that it is possible to treat $f(R)=R\\pm\\mu^4/R$ gravity in a perturbative fashion such that it shows no instabilities on cosmological scales and, in the solar system, is consistent with measurements of the PPN parameters. We show that such a theory produces a spatially flat, accelerating universe, even in the absence of dark energy and when the matter density is too small to close the universe in the general relativistic case.
Gauge theory of gravity and supergravity
Kaul, Romesh K. [Institute of Mathematical Sciences, Chennai 600 113 (India)
2006-03-15T23:59:59.000Z
We present a formulation of gravity in terms of a theory based on complex SU(2) gauge fields with a general coordinate invariant action functional quadratic in the field strength. Self-duality or anti-self-duality of the field strength emerges as a constraint from the equations of motion of this theory. This in turn leads to Einstein gravity equations for a dilaton and an axion conformally coupled to gravity for the self-dual constraint. The analysis has also been extended to N=1 and 2 super Yang-Mills theory of complex SU(2) gauge fields. This leads to, besides other equations of motion, self-duality/anti-self-duality of generalized supercovariant field strengths. The self-dual case is then shown to yield as its solutions N=1, 2 supergravity equations, respectively.
Emergence in Holographic Scenarios for Gravity
Dieks, Dennis; de Haro, Sebastian
2015-01-01T23:59:59.000Z
'Holographic' relations between theories have become an important theme in quantum gravity research. These relations entail that a theory without gravity is equivalent to a gravitational theory with an extra spatial dimension. The idea of holography was first proposed in 1993 by Gerard 't Hooft on the basis of his studies of evaporating black holes. Soon afterwards the holographic 'AdS/CFT' duality was introduced, which since has been intensively studied in the string theory community and beyond. Recently, Erik Verlinde has proposed that even Newton's law of gravitation can be related holographically to the 'thermodynamics of information' on screens. We discuss these scenarios, with special attention to the status of the holographic relation in them and to the question of whether they make gravity and spacetime emergent. We conclude that only Verlinde's scheme straightfowardly instantiates emergence. However, assuming a non-standard interpretation of AdS/CFT may create room for the emergence of spacetime and ...
Rapid gravity and gravity gradiometry terrain correction via adaptive quadtree mesh discretization Kristofer Davis, M. Andy Kass, and Yaoguo Li, Center for Gravity, Electrical and Magnetic Studies, Colorado School of Mines SUMMARY We present a method for modeling the terrain response in gravity and gravity
Standard Model and Gravity from Spinors
F. Nesti
2008-06-20T23:59:59.000Z
We propose to unify the Gravity and Standard Model gauge groups by using algebraic spinors of the standard four-dimensional Clifford algebra, in left-right symmetric fashion. This generates exactly a Standard Model family of fermions, and a Pati-Salam unification group emerges, at the Planck scale, where (chiral) self-dual gravity decouples. As a remnant of the unification, isospin-triplets spin-two particles may naturally appear at the weak scale, providing a striking signal at the LHC.
Differential geometry, Palatini gravity and reduction
Capriotti, S., E-mail: santiago.capriotti@uns.edu.ar [Departamento de Matemática, Universidad Nacional del Sur, 8000 Bahía Blanca (Argentina)
2014-01-15T23:59:59.000Z
The present article deals with a formulation of the so called (vacuum) Palatini gravity as a general variational principle. In order to accomplish this goal, some geometrical tools related to the geometry of the bundle of connections of the frame bundle LM are used. A generalization of Lagrange-Poincaré reduction scheme to these types of variational problems allows us to relate it with the Einstein-Hilbert variational problem. Relations with some other variational problems for gravity found in the literature are discussed.
Geodesic distances in Liouville quantum gravity
Jan Ambjorn; Timothy Budd
2014-11-12T23:59:59.000Z
In order to study the quantum geometry of random surfaces in Liouville gravity, we propose a definition of geodesic distance associated to a Gaussian free field on a regular lattice. This geodesic distance is used to numerically determine the Hausdorff dimension associated to shortest cycles of 2d quantum gravity on the torus coupled to conformal matter fields, showing agreement with a conjectured formula by Y. Watabiki. Finally, the numerical tools are put to test by quantitatively comparing the distribution of lengths of shortest cycles to the corresponding distribution in large random triangulations.
New Spin Foam Models of Quantum Gravity
A. Mikovic
2005-01-28T23:59:59.000Z
We give a brief and a critical review of the Barret-Crane spin foam models of quantum gravity. Then we describe two new spin foam models which are obtained by direct quantization of General Relativity and do not have some of the drawbacks of the Barret-Crane models. These are the model of spin foam invariants for the embedded spin networks in loop quantum gravity and the spin foam model based on the integration of the tetrads in the path integral for the Palatini action.
Testing a Dilaton Gravity Model using Nucleosynthesis
Sibel Boran; Emre Onur Kahya
2014-09-05T23:59:59.000Z
Big Bang Nucleosynthesis (BBN) offers one of the most strict evidences for the Lambda-CDM cosmology at present, as well as the Cosmic Microwave Background (CMB) radiation. In this work, our main aim is to present the outcomes of our calculations related to primordial abundances of light elements, in the context of higher dimensional steady-state universe model in the dilaton gravity. Our results show that abundances of light elements (primordial D, 3He, 4He, T, 7Li) are significantly different for some cases, and a comparison is given between a particular dilaton gravity model and Lambda-CDM in the light of the astrophysical observations.
Inertia and gravitation in teleparallel gravity
R. Aldrovandi; Tiago Gribl Lucas; J. G. Pereira
2009-08-14T23:59:59.000Z
Using the fact that teleparallel gravity allows a separation between gravitation and inertia, explicit expressions for the gravitational and the inertial energy-momentum densities are obtained. It is shown that, like all other fields of nature, gravitation alone has a tensorial energy-momentum density which in a general frame is conserved in the covariant sense. Together with the inertial energy-momentum density, they form a pseudotensor which is conserved in the ordinary sense. An analysis of the role played by the gravitational and the inertial densities in the computation of the total energy and momentum of gravity is presented.
S. F. Hassan; Rachel A. Rosen
2011-11-08T23:59:59.000Z
In massive gravity and in bimetric theories of gravity, two constraints are needed to eliminate the two phase-space degrees of freedom of the Boulware-Deser ghost. For recently proposed non-linear theories, a Hamiltonian constraint has been shown to exist and an associated secondary constraint was argued to arise as well. In this paper we explicitly demonstrate the existence of the secondary constraint. Thus the Boulware-Deser ghost is completely absent from these non-linear massive gravity theories and from the corresponding bimetric theories.
Exact solutions of three dimensional black holes: Einstein gravity vs F(R) gravity
S. H. Hendi; B. Eslam Panah; R. Saffari
2014-10-28T23:59:59.000Z
In this paper, we consider Einstein gravity in the presence of a class of nonlinear electrodynamics, called power Maxwell invariant (PMI). We take into account $(2+1)$-dimensional spacetime in Einstein-PMI gravity and obtain its black hole solutions. Then, we regard pure $F(R)$ gravity as well as $F(R)$-conformally invariant Maxwell theory to obtain exact solutions of the field equations with black hole interpretation. Finally, we investigate the conserved and thermodynamic quantities and discuss about the first law of thermodynamics for the mentioned gravitational models.
One Loop Beta Functions in Topologically Massive Gravity
R. Percacci; E. Sezgin
2010-02-15T23:59:59.000Z
We calculate the running of the three coupling constants in cosmological, topologically massive 3d gravity. We find that \
Komar Integrals in Higher (and Lower) Derivative Gravity
David Kastor
2008-04-24T23:59:59.000Z
The Komar integral relation of Einstein gravity is generalized to Lovelock theories of gravity. This includes, in particular, a new boundary integral for the Komar mass in Einstein gravity with a nonzero cosmological constant, which has a finite result for asymptotically AdS black holes, without the need for an infinite background subtraction. Explicit computations of the Komar mass are given for black holes in pure Lovelock gravities of all orders and in general Gauss-Bonnet theories.
Localisation of Galilean symmetry and Horava-Lifshitz gravity
Banerjee, Rabin
2015-01-01T23:59:59.000Z
We derive the projectable version of Horava-Lifshitz gravity from the localisation of the Galilean symmetry. Specifically we provide a dynamical realisation of the metric that reproduces the transformations of the physical variables - lapse, shift and spatial component of the metric. Also, the measure defining the action is reproduced. The connection of Newton's gravity with Horava-Lifshitz gravity is elucidated.
Gravity Waves in Shear and Implications for Organized Convection
Stechmann, Samuel N.
Gravity Waves in Shear and Implications for Organized Convection Samuel N. Stechmann Department, Los Angeles, CA 90095Â1555. E-mail: stechmann@math.ucla.edu #12;ABSTRACT It is known that gravity, the gravity waves can create a more favorable environment on one side of preexisting convection than the other
Minimal Liouville Gravity on the Torus via Matrix Models
Lev Spodyneiko
2014-07-14T23:59:59.000Z
In this paper we use recent results on resonance relations between the matrix models and the minimal Liouville gravity to compute the torus correlation numbers in (3,p) minimal Liouville gravity. Namely, we calculate the torus generating partition function of the (3,p) matrix models and use it to obtain the one- and two-point correlation numbers in the minimal Liouville gravity.
Tomo-gravity How to ComputeHow to Compute
Roughan, Matthew
Tomo-gravity How to ComputeHow to Compute Accurate Traffic Matrices forAccurate Traffic MatricesStanford Shannon LabShannon Lab #12;Tomo-gravity Want to know demands from source to destination ProblemProblem Have link traffic measurements (from SNMP) A B C #12;Tomo-gravity Example App: reliability analysis
INTERNAL GRAVITY WAVES FROM ATMOSPHERIC JETS AND FRONTS
Plougonven, Riwal
INTERNAL GRAVITY WAVES FROM ATMOSPHERIC JETS AND FRONTS Riwal Plougonven1 and Fuqing Zhang2 consistently highlighted jet exit regions as a favored locus for intense gravity waves, the mechanisms need for improving parameterizations of nonorographic gravity waves in climate models that include
Gravity&MagneticsResearchConsortium CGEMaestro v.1.0
Gravity&MagneticsResearchConsortium CGEMaestro v.1.0 A potential fields software package developed at the Center for Gravity, Electrical & Magnetic Studies (CGEM) Department of Geophysics Colorado School of Mines Golden, CO 80401 http://geophysics.mines.edu/cgem Developed for the sponsors of the Gravity
Recent Results Regarding A#ne Quantum Gravity
Recent Results Regarding A#ne Quantum Gravity John R. Klauder Department of Physics and Department perturbation analysis. After a brief review of both the scalar field story and the a#ne quantum gravity program implies that a#ne quantum gravity is not plagued by divergences that arise in a standard perturbation
Conformal gravity from the AdS/CFT mechanism
Aros, Rodrigo; Romo, Mauricio; Zamorano, Nelson [Departamento de Ciencias Fisicas, Universidad Andres Bello, Av. Republica 252, Santiago (Chile); Departamento de Fisica, Facultad de Ciencias Fisicas y Matematicas, Universidad de Chile, Avda Blanco Encalada 2008, Santiago (Chile)
2007-03-15T23:59:59.000Z
We explicitly calculate the induced gravity theory at the boundary of an asymptotically anti-de Sitter five dimensional Einstein gravity. We also display the action that encodes the dynamics of radial diffeomorphisms. It is found that the induced theory is a four dimensional conformal gravity plus a scalar field. This calculation confirms some previous results found by a different approach.
Quantum Gravity in Three Dimensions from Higher-Spin Holography
Tan, Hai Siong
2013-01-01T23:59:59.000Z
Higher Spin Anti-de Sitter Gravity,” JHEP 1012, 007 (2010)gravity in three dimensions from the per- spective of higher-spin holography in anti-gravity in three dimen- sions in the framework of higher-spin holography in anti-
Observing ocean heat content using satellite gravity and altimetry
Jayne, Steven
: ocean heat content, altimetry, satellite gravity, steric height, remote sensing Citation: Jayne, S. RObserving ocean heat content using satellite gravity and altimetry Steven R. Jayne1,2 and John M with satellite measurements of the Earth's time-varying gravity to give improved estimates of the ocean's heat
HoravaLifshitz gravity Victoria University of Wellington
Visser, Matt
Abstract HoravaÂLifshitz gravity Victoria University of Wellington Te Whare WÂŻananga o te ÂŻUpoko o Vancouver Tuesday 25 August 2009 Matt Visser Who's afraid of Lorentz symmetry breaking? #12;Abstract HoravaÂLifshitz gravity HoravaÂLifshitz gravity: As of 23 August 2009 Spires reports that this topic has generated: 3
The Mars Gravity Biosatellite as an innovative partial gravity research platform
Fulford-Jones, Thaddeus R. F
2008-01-01T23:59:59.000Z
The Mars Gravity Biosatellite is an unprecedented independent spaceflight platform for gravitational biology research. With a projected first launch after 2010, the low Earth orbit satellite will support a cohort of fifteen ...
Schwarzschild solution in extended teleparallel gravity
G. G. L. Nashed
2015-01-05T23:59:59.000Z
Tetrad field, with two unknown functions of radial coordinate and an angle $\\Phi$ which is the polar angle $\\phi$ times a function of the redial coordinate, is applied to the field equation of modified theory of gravity. Exact vacuum solution is derived whose scalar torsion, $T ={T^\\alpha}_{\\mu \
Explicit versus Spontaneous Diffeomorphism Breaking in Gravity
Robert Bluhm
2015-04-02T23:59:59.000Z
Gravitational theories with fixed background fields break local Lorentz and diffeomorphism invariance either explicitly or spontaneously. In the case of explicit breaking it is known that conflicts can arise between the dynamics and geometrical constraints, while spontaneous breaking evades this problem. It is for this reason that in the gravity sector of the Standard-Model Extension (SME) it is assumed that the background fields (SME coefficients) originate from spontaneous symmetry breaking. However, in other examples, such as Chern-Simons gravity and massive gravity, diffeomorphism invariance is explicitly broken by the background fields, and the potential conflicts between the dynamics and geometry can be avoided in most cases. An analysis of how this occurs is given, and the conditions that are placed on the metric tensor and gravitational structure as a result of the presence of an explicit-breaking background are described. The gravity sector of the SME is then considered for the case of explicit breaking. However, it is found that a useful post-Newtonian limit is only obtained when the symmetry breaking is spontaneous.
Einstein-aether gravity: a status report
Ted Jacobson
2008-03-09T23:59:59.000Z
This paper reviews the theory, phenomenology, and observational constraints on the coupling parameters of Einstein-aether gravity, i.e. General Relativity coupled to a dynamical unit timelike vector field. A discussion of open questions concerning both phenomenology and fundamental issues is included.
MODIFIED GRAVITY SPINS UP GALACTIC HALOS
Lee, Jounghun [Astronomy Program, Department of Physics and Astronomy, FPRD, Seoul National University, Seoul 151-747 (Korea, Republic of)] [Astronomy Program, Department of Physics and Astronomy, FPRD, Seoul National University, Seoul 151-747 (Korea, Republic of); Zhao, Gong-Bo [National Astronomy Observatories, Chinese Academy of Science, Beijing 100012 (China)] [National Astronomy Observatories, Chinese Academy of Science, Beijing 100012 (China); Li, Baojiu [Institute of Computational Cosmology, Department of Physics, Durham University, Durham DH1 3LE (United Kingdom)] [Institute of Computational Cosmology, Department of Physics, Durham University, Durham DH1 3LE (United Kingdom); Koyama, Kazuya, E-mail: jounghun@astro.snu.ac.kr [Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth, PO1 3FX (United Kingdom)] [Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth, PO1 3FX (United Kingdom)
2013-01-20T23:59:59.000Z
We investigate the effect of modified gravity on the specific angular momentum of galactic halos by analyzing the halo catalogs at z = 0 from high-resolution N-body simulations for a f(R) gravity model that meets the solar-system constraint. It is shown that the galactic halos in the f(R) gravity model tend to acquire significantly higher specific angular momentum than those in the standard {Lambda}CDM model. The largest difference in the specific angular momentum distribution between these two models occurs for the case of isolated galactic halos with mass less than 10{sup 11} h {sup -1} M {sub Sun }, which are likely least shielded by the chameleon screening mechanism. As the specific angular momentum of galactic halos is rather insensitive to other cosmological parameters, it can in principle be an independent discriminator of modified gravity. We speculate a possibility of using the relative abundance of low surface brightness galaxies (LSBGs) as a test of general relativity given that the formation of the LSBGs occurs in fast spinning dark halos.
Black Hole Solutions in $R^2$ Gravity
Kehagias, Alex; Lust, Dieter; Riotto, Antonio
2015-01-01T23:59:59.000Z
We find static spherically symmetric solutions of scale invariant $R^2$ gravity. The latter has been shown to be equivalent to General Relativity with a positive cosmological constant and a scalar mode. Therefore, one expects that solutions of the $R^2$ theory will be identical to that of Einstein theory. Indeed, we find that the solutions of $R^2$ gravity are in one-to-one correspondence with solutions of General Relativity in the case of non-vanishing Ricci scalar. However, scalar-flat $R=0$ solutions are global minima of the $R^2$ action and they cannot in general be mapped to solutions of the Einstein theory. As we will discuss, the $R=0$ solutions arise in Einstein gravity as solutions in the tensionless, strong coupling limit $M_P\\rightarrow 0$. As a further result, there is no corresponding Birkhoff theorem and the Schwarzschild black hole is by no means unique in this framework. In fact, $R^2$ gravity has a rich structure of vacuum static spherically symmetric solutions partially uncovered here. We al...
Attraction and Repulsion in Conformal Gravity
Phillips, Peter R
2015-01-01T23:59:59.000Z
We use numerical integration to solve the field equations of conformal gravity, assuming a metric that is static and spherically symmetric. Our solution is an extension of that found by Mannheim and Kazanas; it indicates, as expected, that gravitation in this model should be attractive on small scales and repulsive on large ones.
Motion in Bimetric Type Theories of Gravity
Kahil, M E
2015-01-01T23:59:59.000Z
The problem of motion for different test particles, charged and spinning objects of constant spinning tensor in different versions of bimetric theory of gravity is obtained by deriving their corresponding path and path deviation equations, using a modified Bazanski in presence of Riemannian geometry. This method enables us to find path and path deviation equations of different objects orbiting very strong gravitational fields.
Scale invariance, unimodular gravity and dark energy
Mikhail Shaposhnikov; Daniel Zenhausern
2008-12-16T23:59:59.000Z
We demonstrate that the combination of the ideas of unimodular gravity, scale invariance, and the existence of an exactly massless dilaton leads to the evolution of the universe supported by present observations: inflation in the past, followed by the radiation and matter dominated stages and accelerated expansion at present. All mass scales in this type of theories come from one and the same source.
Ultrasonic hydrometer. [Specific gravity of electrolyte
Swoboda, C.A.
1982-03-09T23:59:59.000Z
The disclosed ultrasonic hydrometer determines the specific gravity (density) of the electrolyte of a wet battery, such as a lead-acid battery. The hydrometer utilizes a transducer that when excited emits an ultrasonic impulse that traverses through the electrolyte back and forth between spaced sonic surfaces. The transducer detects the returning impulse, and means measures the time t between the initial and returning impulses. Considering the distance d between the spaced sonic surfaces and the measured time t, the sonic velocity V is calculated with the equation V = 2d/t. The hydrometer also utilizes a thermocouple to measure the electrolyte temperature. A hydrometer database correlates three variable parameters including sonic velocity in and temperature and specific gravity of the electrolyte, for temperature values between 0 and 40/sup 0/C and for specific gravity values between 1.05 and 1.30. Upon knowing two parameters (the calculated sonic velocity and the measured temperature), the third parameter (specific gravity) can be uniquely found in the database. The hydrometer utilizes a microprocessor for data storage and manipulation.
Infrared fixed point in quantum Einstein gravity
S. Nagy; J. Krizsan; K. Sailer
2012-06-28T23:59:59.000Z
We performed the renormalization group analysis of the quantum Einstein gravity in the deep infrared regime for different types of extensions of the model. It is shown that an attractive infrared point exists in the broken symmetric phase of the model. It is also shown that due to the Gaussian fixed point the IR critical exponent $\
The diffeomorphism algebra approach to quantum gravity
T. A. Larsson
1999-09-13T23:59:59.000Z
The representation theory of non-centrally extended Lie algebras of Noether symmetries, including spacetime diffeomorphisms and reparametrizations of the observer's trajectory, has recently been developped. It naturally solves some long-standing problems in quantum gravity, e.g. the role of diffeomorphisms and the causal structure, but some new questions also arise.
Landscape versus Swampland for Higher Derivative Gravity
Sho Yaida
2009-02-10T23:59:59.000Z
We survey recent studies of Gauss-Bonnet gravity and its dual conformal field theories, including their relation to the violation of the Kovtun-Starinets-Son viscosity bound. Via holography, we can also study properties such as microcausality and unitarity of boundary field theory duals. Such studies in turn supply constraints on bulk gravitational theories, consigning some of them to the swampland.
A New Model of Nonlocal Modified Gravity
Ivan Dimitrijevic; Branko Dragovich; Jelena Grujic; Zoran Rakic
2014-11-18T23:59:59.000Z
We consider a new modified gravity model with nonlocal term of the form $R^{-1} \\mathcal{F}(\\Box) R. $ This kind of nonlocality is motivated by investigation of applicability of a few unusual ans\\"atze to obtain some exact cosmological solutions. In particular, we find attractive and useful quadratic ansatz $\\Box R = q R^{2}.$
Gravity and the Quantum: Are they Reconcilable?
R. Aldrovandi; J. G. Pereira; K. H. Vu
2005-09-14T23:59:59.000Z
General relativity and quantum mechanics are conflicting theories. The seeds of discord are the fundamental principles on which these theories are grounded. General relativity, on one hand, is based on the equivalence principle, whose strong version establishes the local equivalence between gravitation and inertia. Quantum mechanics, on the other hand, is fundamentally based on the uncertainty principle, which is essentially nonlocal in the sense that a particle does not follow one trajectory, but infinitely many trajectories, each one with a different probability. This difference precludes the existence of a quantum version of the strong equivalence principle, and consequently of a quantum version of general relativity. Furthermore, there are compelling experimental evidences that a quantum object in the presence of a gravitational field violates the weak equivalence principle. Now it so happens that, in addition to general relativity, gravitation has an alternative, though equivalent description, given by teleparallel gravity, a gauge theory for the translation group. In this theory torsion, instead of curvature, is assumed to represent the gravitational field. These two descriptions lead to the same classical results, but are conceptually different. In general relativity, curvature geometrizes the interaction, while torsion in teleparallel gravity acts as a force, similar to the Lorentz force of electrodynamics. Because of this peculiar property, teleparallel gravity describes the gravitational interaction without requiring any of the equivalence principles. The replacement of general relativity by teleparallel gravity may, in consequence, lead to a conceptual reconciliation of gravitation with quantum mechanics.
Energy definition for quadratic curvature gravities
Ahmet Baykal
2012-12-03T23:59:59.000Z
A conserved current for generic quadratic curvature gravitational models is defined, and it is shown that, at the linearized level, it corresponds to the Deser-Tekin charges. An explicit expression for the charge for new massive gravity in three dimensions is given. Some implications of the linearized equations are discussed.
Topological Black Holes in Quantum Gravity
J. Kowalski-Glikman; D. Nowak-Szczepaniak
2000-07-31T23:59:59.000Z
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.
Sart, Remi
Approaches to Quantum Gravity, Clermont-Ferrand, Jan. 6, 2014 Fractal dimensions of 2d quantum gravity Timothy Budd Niels Bohr Institute, Copenhagen. budd@nbi.dk, http://www.nbi.dk/~budd/ #12;Outline Introduction to 2d gravity Fractal dimensions Hausdorff dimension dh "TeichmÂ¨uller deformation dimension" d
Taylor-mccabe, Kirsten J [Los Alamos National Laboratory; Wingo, Robert M [Los Alamos National Laboratory; Haarmann, Timothy K [Los Alamos National Laboratory
2008-01-01T23:59:59.000Z
We examined honey bee's associative learning response to conditioning with trinitrotolulene (TNT) vapor concentrations generated at three temperatures and their ability to be reconditioned after a 24 h period. We used classical conditioning of the proboscis extension (PER) in honey bees using TNT vapors as the conditioned stimulus and sucrose as the unconditioned stimulus. We conducted fifteen experimental trials with an explosives vapor generator set at 43 C, 25 C and 5 C, producing three concentrations of explosives (1070 ppt, 57 ppt, and 11 ppt). Our objective was to test the honey bee's ability to exhibit a conditioned response to TNT vapors at all three concentrations by comparing the mean percentage of honey bees successfully exhibiting a conditioned response within each temperature group. Furthermore, we conducted eight experimental trials to test the honey bee's ability to retain their ability to exhibit a conditioned response to TNT after 24h period by comparing the mean percentage of honey bees with a conditioned response TNT on the first day compared to the percentage of honey bees with a conditioned response to TNT on the second day. Results indicate that there was no significant difference between the mean percentage of honey bees with a conditioned response to TNT vapors between three temperature groups. There was a significant difference between the percentage of honey bees exhibiting conditioned response on the first day of training compared to the percentage of honey bees exhibiting conditioned response 24 h after training. Our experimental results indicate that honey bees can be trained to exhibit a conditioned response to a range of TNT concentrations via PER However, it appears that the honey bee's ability to retain the conditioned response to TNT vapors after 24h significantly decreases.
Constraining the Kehagias-Sfetsos solution in the Horava-Lifshitz gravity with extrasolar planets
Lorenzo Iorio; Matteo Luca Ruggiero
2010-10-04T23:59:59.000Z
We consider a spherically symmetric and asymptotically flat vacuum solution of the Horava-Lifshitz (HL) gravity that is the analog of the general relativistic Schwarzschild black hole. In the weak-field and slow-motion approximation, we work out the correction to the third Kepler law of a test particle induced by such a solution and compare it to the phenomenologically determined orbital period of the transiting extrasolar planet HD209458b Osiris to preliminarily obtain an order-of-magnitude lower bound on the KS dimensionless parameter \\omega_0 >= 1.4\\times 10^-18. As suggestions for further analyses, the entire data set of HD209458b should be re-processed by explicitly modeling KS gravity as well, and one or more dedicated solve-for parameter(s) should be estimated.
The Chern-Simons diffusion rate from higher curvature gravity
Viktor Jahnke; Anderson Seigo Misobuchi; Diego Trancanelli
2014-03-13T23:59:59.000Z
An important transport coefficient in the study of non-Abelian plasmas is the Chern-Simons diffusion rate, which parameterizes the rate of transition among the degenerate vacua of a gauge theory. We compute this quantity at strong coupling, via holography, using two theories of gravity with higher curvature corrections, namely Gauss-Bonnet gravity and quasi-topological gravity. We find that these corrections may either increase or decrease the result obtained from Einstein's gravity, depending on the value of the couplings. The Chern-Simons diffusion rate for Gauss-Bonnet gravity decreases as the shear viscosity over entropy ratio is increased.
On the z=4 Horava-Lifshitz Gravity
Rong-Gen Cai; Yan Liu; Ya-Wen Sun
2009-06-04T23:59:59.000Z
We consider z=4 Horava-Lifshitz gravity in both 3+1 and 4+1 dimensions. We find black hole solutions in the IR region for a kind of z=4 Horava-Lifshitz gravity which is inherited from the new massive gravity in three dimensions and an analog of the new massive gravity in four dimensions through the quantum inheritance principle. We analyze thermodynamic properties for the black hole solutions for z=4 Horava-Lifshitz gravity. We also write out the Friedmann equation in 3+1 dimensions for cosmological solutions.
Taub-NUT Black Holes in Third order Lovelock Gravity
S. H. Hendi; M. H. Dehghani
2008-08-05T23:59:59.000Z
We consider the existence of Taub-NUT solutions in third order Lovelock gravity with cosmological constant, and obtain the general form of these solutions in eight dimensions. We find that, as in the case of Gauss-Bonnet gravity and in contrast with the Taub-NUT solutions of Einstein gravity, the metric function depends on the specific form of the base factors on which one constructs the circle fibration. Thus, one may say that the independence of the NUT solutions on the geometry of the base space is not a robust feature of all generally covariant theories of gravity and is peculiar to Einstein gravity. We find that when Einstein gravity admits non-extremal NUT solutions with no curvature singularity at $r=N$, then there exists a non-extremal NUT solution in third order Lovelock gravity. In 8-dimensional spacetime, this happens when the metric of the base space is chosen to be $\\Bbb{CP}^{3}$. Indeed, third order Lovelock gravity does not admit non-extreme NUT solutions with any other base space. This is another property which is peculiar to Einstein gravity. We also find that the third order Lovelock gravity admits extremal NUT solution when the base space is $T^{2}\\times T^{2}\\times T^{2}$ or $S^{2}\\times T^{2}\\times T^{2}$. We have extended these observations to two conjectures about the existence of NUT solutions in Lovelock gravity in any even-dimensional spacetime.
The equilibrium of dense plasma in a gravity field
B. V. Vasiliev
2000-10-31T23:59:59.000Z
The equilibrium of dense plasma in a gravity field and problem of a gravity-induced electric polarization in this matter are discussed. The calculation for metals performed before shows that both - the gravity-induced compressive strain and the gravity-induced electric field - are inversely proportional to their Young moduli. The calculation for high dense plasma, where Young modulus is equal to zero, shows that there is another effect: each cell of this plasma inside a celestial body in own gravity field obtains the small positive electric charge. It happens as heavy ions sag on to light electron clouds. A celestial body stays electrically neutral as a whole, because the negative electric charge concentrates on its surface. The gravity-induced positive volume charge is very small, its order of magnitude equals to $10^{-18}e$ per atom only. But it is sufficient for the complete conterbalancing of the gravity force.
In quantum gravity, summing is refining
Carlo Rovelli; Matteo Smerlak
2011-05-03T23:59:59.000Z
In perturbative QED, the approximation is improved by summing more Feynman graphs; in non-perturbative QCD, by refining the lattice. Here we observe that in quantum gravity the two procedures may well be the same. We outline the combinatorial structure of spinfoam quantum gravity, define the continuum limit, and show that under general conditions refining foams is the same as summing over them. The conditions bear on the cylindrical consistency of the spinfoam amplitudes and on the presence of appropriate combinatorial factors, related to the implementation of diffeomorphisms invariance. Intuitively, the sites of the lattice are points of space: these are themselves quanta of the gravitational field, and thus a lattice discretization is also a Feynman history of quanta.
Phenomenology of Irreversible Processes from Gravity
Ramakrishnan Iyer; Ayan Mukhopadhyay
2011-11-17T23:59:59.000Z
We propose that the space-time evolution of strongly coupled matter formed by ultra-relativistic heavy ion collisions can be modelled by phenomenological equations involving the energy-momentum tensor and conserved currents alone. These equations can describe the late stage of local chemical and thermal equilibration of the matter formed after collisions, and its subsequent transition to hydrodynamic expansion in an unified framework. The full set of equations include local energy, momentum and charge conservation; but also additional equations for evolution of non-equilibrium variables. These equations with precisely determined phenomenological parameters can be obtained by the AdS/CFT correspondence. On the gravity side of this correspondence, for vanishing chemical potentials, these phenomenological equations give all solutions of pure gravity in AdS which have regular future horizons. We also discuss field-theoretic grounds for validity of these phenomenological equations.
Holographic studies of quasi-topological gravity
Robert C. Myers; Miguel F. Paulos; Aninda Sinha
2010-06-09T23:59:59.000Z
Quasi-topological gravity is a new gravitational theory including curvature-cubed interactions and for which exact black hole solutions were constructed. In a holographic framework, classical quasi-topological gravity can be thought to be dual to the large $N_c$ limit of some non-supersymmetric but conformal gauge theory. We establish various elements of the AdS/CFT dictionary for this duality. This allows us to infer physical constraints on the couplings in the gravitational theory. Further we use holography to investigate hydrodynamic aspects of the dual gauge theory. In particular, we find that the minimum value of the shear-viscosity-to-entropy-density ratio for this model is $\\eta/s \\simeq 0.4140/(4\\pi)$.
Black holes in Asymptotically Safe Gravity
Saueressig, Frank; D'Odorico, Giulio; Vidotto, Francesca
2015-01-01T23:59:59.000Z
Black holes are among the most fascinating objects populating our universe. Their characteristic features, encompassing spacetime singularities, event horizons, and black hole thermodynamics, provide a rich testing ground for quantum gravity ideas. In this note we observe that the renormalization group improved Schwarzschild black holes constructed by Bonanno and Reuter within Weinberg's asymptotic safety program constitute a prototypical example of a Hayward geometry used to model non-singular black holes within quantum gravity phenomenology. Moreover, they share many features of a Planck star: their effective geometry naturally incorporates the one-loop corrections found in the effective field theory framework, their Kretschmann scalar is bounded, and the black hole singularity is replaced by a regular de Sitter patch. The role of the cosmological constant in the renormalization group improvement process is briefly discussed.
Elliptic Genera and 3d Gravity
Benjamin, Nathan; Kachru, Shamit; Moore, Gregory W; Paquette, Natalie M
2015-01-01T23:59:59.000Z
We describe general constraints on the elliptic genus of a 2d supersymmetric conformal field theory which has a gravity dual with large radius in Planck units. We give examples of theories which do and do not satisfy the bounds we derive, by describing the elliptic genera of symmetric product orbifolds of $K3$, product manifolds, certain simple families of Calabi-Yau hypersurfaces, and symmetric products of the "Monster CFT." We discuss the distinction between theories with supergravity duals and those whose duals have strings at the scale set by the AdS curvature. Under natural assumptions we attempt to quantify the fraction of (2,2) supersymmetric conformal theories which admit a weakly curved gravity description, at large central charge.
Chaotic inflation in higher derivative gravity theories
Myrzakul, Shynaray; Sebastiani, Lorenzo
2015-01-01T23:59:59.000Z
In this paper, we investigate chaotic inflation from scalar field subjected to potential in the framework of $f(R^2, P, Q)$-gravity, where we add a correction to Einstein's gravity based on a function of the square of the Ricci scalar $R^2$, the contraction of the Ricci tensor $P$, and the contraction of the Riemann tensor $Q$. The Gauss-Bonnet case is also discussed. We give the general formalism of inflation, deriving the slow-roll parameters, the $e$-folds number, and the spectral indexes. Several explicit examples are furnished, namely we will consider the cases of massive scalar field and scalar field with quartic potential and some power-law function of the curvature invariants under investigation in the gravitational action of the theory. Viable inflation according with observations is analyzed.
Propagation of gravitational waves in multimetric gravity
Manuel Hohmann
2012-04-22T23:59:59.000Z
We discuss the propagation of gravitational waves in a recently discussed class of theories containing N >= 2 metric tensors and a corresponding number of standard model copies. Using the formalism of gauge-invariant linear perturbation theory we show that all gravitational waves propagate at the speed of light. We then employ the Newman-Penrose formalism to show that two to six polarizations of gravitational waves may exist, depending on the parameters entering the equations of motion. This corresponds to E(2) representations N_2, N_3, III_5 and II_6. We finally apply our general discussion to a recently presented concrete multimetric gravity model and show that it is of class N_2, i.e., it allows only two tensor polarizations, as it is the case for general relativity. Our results provide the theoretical background for tests of multimetric gravity theories using the upcoming gravitational wave experiments.
Detecting individual gravity modes in the Sun
Garcia, R A; Eff-Darwich, A; Garrido, R; Jimenez, A; Mathis, S; Moya, A; Palle, P L; Regulo, C; Salabert, D; Suarez, J C; Turck-Chieze, S
2009-01-01T23:59:59.000Z
Many questions are still open regarding the structure and the dynamics of the solar core. By constraining more this region in the solar evolution models, we can reduce the incertitudes on some physical processes and on momentum transport mechanisms. A first big step was made with the detection of the signature of the dipole-gravity modes in the Sun, giving a hint of a faster rotation rate inside the core. A deeper analysis of the GOLF/SoHO data unveils the presence of a pattern of peaks that could be interpreted as dipole gravity modes. In that case, those modes can be characterized, thus bringing better constraints on the rotation of the core as well as some structural parameters such as the density at these very deep layers of the Sun interior.
Quantum gravity at a Lifshitz point
Horava, Petr [Berkeley Center for Theoretical Physics and Department of Physics, University of California, Berkeley, California, 94720-7300 (United States) and Physics Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720-8162 (United States)
2009-04-15T23:59:59.000Z
We present a candidate quantum field theory of gravity with dynamical critical exponent equal to z=3 in the UV. (As in condensed-matter systems, z measures the degree of anisotropy between space and time.) This theory, which at short distances describes interacting nonrelativistic gravitons, is power-counting renormalizable in 3+1 dimensions. When restricted to satisfy the condition of detailed balance, this theory is intimately related to topologically massive gravity in three dimensions, and the geometry of the Cotton tensor. At long distances, this theory flows naturally to the relativistic value z=1, and could therefore serve as a possible candidate for a UV completion of Einstein's general relativity or an infrared modification thereof. The effective speed of light, the Newton constant and the cosmological constant all emerge from relevant deformations of the deeply nonrelativistic z=3 theory at short distances.
Hydrogen atom in Palatini theories of gravity
Gonzalo J. Olmo
2008-06-03T23:59:59.000Z
We study the effects that the gravitational interaction of $f(R)$ theories of gravity in Palatini formalism has on the stationary states of the Hydrogen atom. We show that the role of gravity in this system is very important for lagrangians $f(R)$ with terms that grow at low curvatures, which have been proposed to explain the accelerated expansion rate of the universe. We find that new gravitationally induced terms in the atomic Hamiltonian generate a strong backreaction that is incompatible with the very existence of bound states. In fact, in the 1/R model, Hydrogen disintegrates in less than two hours. The universe that we observe is, therefore, incompatible with that kind of gravitational interaction. Lagrangians with high curvature corrections do not lead to such instabilities.
Non-metric gravity: A status report
Kirill Krasnov
2007-11-05T23:59:59.000Z
We review the status of a certain (infinite) class of four-dimensional generally covariant theories propagating two degrees of freedom that are formulated without any direct mention of the metric. General relativity itself (in its Plebanski formulation) belongs to the class, so these theories are examples of modified gravity. We summarize the current understanding of the nature of the modification, of the renormalizability properties of these theories, of their coupling to matter fields, and describe some of their physical properties.
The Hausdorff dimension in polymerized quantum gravity
Martin G. Harris; John F. Wheater
1998-11-24T23:59:59.000Z
We calculate the Hausdorff dimension, $d_H$, and the correlation function exponent, $\\eta$, for polymerized two dimensional quantum gravity models. If the non-polymerized model has correlation function exponent $\\eta_0 >3$ then $d_H=\\gamma^{-1}$ where $\\gamma$ is the susceptibility exponent. This suggests that these models may be in the same universality class as certain non-generic branched polymer models.
A Thermodynamic Sector of Quantum Gravity
J. Oppenheim
2001-12-04T23:59:59.000Z
The connection between gravity and thermodynamics is explored. Examining a perfect fluid in gravitational equilibrium we find that the entropy is extremal only if Einstein's equations are satisfied. Conversely, one can derive part of Einstein's equations from ordinary thermodynamical considerations. This allows the theory of this system to be recast in such a way that a sector of general relativity is purely thermodynamical and should not be quantized.
Redshift Distortions as a Probe of Gravity
Eric V. Linder
2007-09-07T23:59:59.000Z
Redshift distortion measurements from galaxy surveys include sensitivity to the gravitational growth index distinguishing other theories from Einstein gravity. This gravitational sensitivity is substantially free from uncertainty in the effective equation of state of the cosmic expansion history. We also illustrate the bias in the traditional application to matter density determination using f=Omega_m(a)^{0.6}, and how to avoid it.
Gravity controlled anti-reverse rotation device
Dickinson, Robert J. (Shaler Township, Allegheny County, PA); Wetherill, Todd M. (Lower Burrell, PA)
1983-01-01T23:59:59.000Z
A gravity assisted anti-reverse rotation device for preventing reverse rotation of pumps and the like. A horizontally mounted pawl is disposed to mesh with a fixed ratchet preventing reverse rotation when the pawl is advanced into intercourse with the ratchet by a vertically mounted lever having a lumped mass. Gravitation action on the lumped mass urges the pawl into mesh with the ratchet, while centrifugal force on the lumped mass during forward, allowed rotation retracts the pawl away from the ratchet.
Holographic Superconductors in Horava-Lifshitz Gravity
Kai Lin; Elcio Abdalla; Anzhong Wang
2014-06-18T23:59:59.000Z
We consider holographic superconductors related to the Schwarzschild black hole in the low energy limit of Ho\\v{r}ava-Lifshitz spacetime. The non-relativistic electromagnetic and scalar fields are introduced to construct a holographic superconductor model in Ho\\v{r}ava-Lifshitz gravity and the results show that the $\\alpha_2$ term plays an important role, modifying the conductivity curve line by means of an attenuation the conductivity.
Exact Gravity Dual of a Gapless Superconductor
George Koutsoumbas; Eleftherios Papantonopoulos; George Siopsis
2009-06-17T23:59:59.000Z
A model of an exact gravity dual of a gapless superconductor is presented in which the condensate is provided by a charged scalar field coupled to a bulk black hole of hyperbolic horizon in asymptotically AdS spacetime. Below a critical temperature, the black hole acquires its hair through a phase transition while an electromagnetic perturbation of the background Maxwell field determines the conductivity of the boundary theory.
Holographic Superconductivity with Gauss-Bonnet gravity
Ruth Gregory
2010-12-07T23:59:59.000Z
I review recent work on holographic superconductivity with Einstein-Gauss-Bonnet gravity, and show how the critical temperature of the superconductor depends on both gravitational backreaction and the Gauss-Bonnet parameter, using both analytic and numerical arguments. I also review computations of the conductivity, finding the energy gap, and demonstrating that there is no universal gap ratio, $\\omega_g/T_c$, for these superconductors.
Cosmology with Coupled Gravity and Dark Energy
Ti-Pei Li
2015-01-13T23:59:59.000Z
Dark energy is a fundamental constituent of our universe, its status in the cosmological field equation should be equivalent to that of gravity. Here we construct a dark energy and matter gravity coupling (DEMC) model of cosmology in a way that dark energy and gravity are introduced into the cosmological field equation in parallel with each other from the beginning. The DEMC universe possesses a composite symmetry from global Galileo invariance and local Lorentz invariance. The observed evolution of the universe expansion rate at redshift z>1 is in tension with the standard LCDM model, but can be well predicted by the DEMC model from measurements of only nearby epochs. The so far most precise measured expansion rate at high z is quite a bit slower than the expectations from LCDM, but remarkably consistent with that from DEMC. It is hoped that the DEMC scenario can also help to solve other existing challenges to cosmology: large scale anomalies in CMB maps and large structures up to about 10^3 Mpc of a quasar group. The DEMC universe is a well defined mechanical system. From measurements we can quantitatively evaluate its total rest energy, present absolute radius and expanding speed.
Abelian-Higgs strings in Rastall gravity
Eugenio R. Bezerra de Mello; Julio C. Fabris; Betti Hartmann
2015-04-02T23:59:59.000Z
In this paper we analyze Abelian-Higgs strings in a phenomenological model that takes quantum effects in curved space-time into account. This model, first introduced by Rastall, cannot be derived from an action principle. We formulate phenomenological equations of motion under the guiding principle of minimal possible deformation of the standard equations. We construct string solutions that asymptote to a flat space-time with a deficit angle by solving the set of coupled non-linear ordinary differential equations numerically. Decreasing the Rastall parameter from its Einstein gravity value we find that the deficit angle of the space-time increases and becomes equal to $2\\pi$ at some critical value of this parameter that depends on the remaining couplings in the model. For smaller values the resulting solutions are supermassive string solutions possessing a singularity at a finite distance from the string core. Assuming the Higgs boson mass to be on the order of the gauge boson mass we find that also in Rastall gravity this happens only when the symmetry breaking scale is on the order of the Planck mass. We also observe that for specific values of the parameters in the model the energy per unit length becomes proportional to the winding number, i.e. the degree of the map $S^1 \\rightarrow S^1$. Unlike in the BPS limit in Einstein gravity, this is, however, not connect to an underlying mathematical structure, but rather constitutes a would-be-BPS bound.
Down hole periodic seismic generator
Hardee, Harry C. (Albuquerque, NM); Hills, Richard G. (Las Cruces, NM); Striker, Richard P. (Albuquerque, NM)
1989-01-01T23:59:59.000Z
A down hole periodic seismic generator system for transmitting variable frequency, predominantly shear-wave vibration into earth strata surrounding a borehole. The system comprises a unitary housing operably connected to a well head by support and electrical cabling and contains clamping apparatus for selectively clamping the housing to the walls of the borehole. The system further comprises a variable speed pneumatic oscillator and a self-contained pneumatic reservoir for producing a frequency-swept seismic output over a discrete frequency range.
Advanced downhole periodic seismic generator
Hardee, Harry C. (Albuquerque, NM); Hills, Richard G. (Las Cruces, NM); Striker, Richard P. (Albuquerque, NM)
1991-07-16T23:59:59.000Z
An advanced downhole periodic seismic generator system for transmitting variable frequency, predominantly shear-wave vibration into earth strata surrounding a borehole. The system comprises a unitary housing operably connected to a well head by support and electrical cabling and contains clamping apparatus for selectively clamping the housing to the walls of the borehole. The system further comprises a variable speed pneumatic oscillator and a self-contained pneumatic reservoir for producing a frequency-swept seismic output over a discrete frequency range.
Solar System experiments do not yet veto modified gravity models
Valerio Faraoni
2006-07-05T23:59:59.000Z
The dynamical equivalence between modified and scalar-tensor gravity theories is revisited and it is concluded that it breaks down in the limit to general relativity. A gauge-independent analysis of cosmological perturbations in both classes of theories lends independent support to this conclusion. As a consequence, the PPN formalism of scalar-tensor gravity and Solar System experiments do not veto modified gravity, as previously thought.
AdS waves as exact solutions to quadratic gravity
Guellue, Ibrahim; Sisman, Tahsin Cagri; Tekin, Bayram [Department of Physics, Middle East Technical University, 06531 Ankara (Turkey); Guerses, Metin [Department of Mathematics, Faculty of Sciences Bilkent University, 06800 Ankara (Turkey)
2011-04-15T23:59:59.000Z
We give an exact solution of the quadratic gravity in D dimensions. The solution is a plane-fronted wave metric with a cosmological constant. This metric solves not only the full quadratic gravity field equations but also the linearized ones which include the linearized equations of the recently found critical gravity. A subset of the solutions change the asymptotic structure of the anti-de Sitter space due to their logarithmic behavior.
Using precision gravity data in geothermal reservoir engineering modeling studies
Atkinson, Paul G.; Pederseen, Jens R.
1988-01-01T23:59:59.000Z
Precision gravity measurements taken at various times over a geothermal field can be used to derive information about influx into the reservoir. Output from a reservoir simulation program can be used to compute surface gravity fields and time histories. Comparison of such computer results with field-measured gravity data can add confidence to simulation models, and provide insight into reservoir processes. Such a comparison is made for the Bulalo field in the Philippines.
Gravity Survey of the Carson Sink - Data and Maps
Faulds, James E.
2013-12-31T23:59:59.000Z
A detailed gravity survey was carried out for the entire Carson Sink in western Nevada (Figure 1) through a subcontract to Zonge Engineering, Inc. The Carson Sink is a large composite basin containing three known, blind high?temperature geothermal systems (Fallon Airbase, Stillwater, and Soda Lake). This area was chosen for a detailed gravity survey in order to characterize the gravity signature of the known geothermal systems and to identify other potential blind systems based on the structural setting indicated by the gravity data. Data: Data were acquired at approximately 400, 800, and 1600 meter intervals for a total of 1,243 stations. The project location and station location points are presented in Figure 14. The station distribution for this survey was designed to complete regional gravity coverage in the Carson Sink area without duplication of available public and private gravity coverage. Gravity data were acquired using a Scintrex CG?5 gravimeter and a LaCoste and Romberg (L&R) Model?G gravimeter. The CG?5 gravity meter has a reading resolution of 0.001 milligals and a typical repeatability of less than 0.005 milligals. The L&R gravity meter has a reading resolution of 0.01 milligals and a typical repeatability of 0.02 milligals. The basic processing of gravimeter readings to calculate through to the Complete Bouguer Anomaly was made using the Gravity and Terrain Correction software version 7.1 for Oasis Montaj by Geosoft LTD. Results: The gravity survey of the Carson Sink yielded the following products. Project location and station location map (Figure 14). Complete Bouguer Anomaly @ 2.67 gm/cc reduction density. Gravity Complete Bouguer Anomaly at 2.50 g/cc Contour Map (Figure 15). Gravity Horizontal Gradient Magnitude Shaded Color Contour Map. Gravity 1st Vertical Derivative Color Contour Map. Interpreted Depth to Mesozoic Basement (Figure 16), incorporating drill?hole intercept values. Preliminary Interpretation of Results: The Carson Sink is a complex composite basin with several major depocenters (Figures 15 and 16). Major depocenters are present in the south?central, east?central, and northeastern parts of the basin. The distribution of gravity anomalies suggests a complex pattern of faulting in the subsurface of the basin, with many fault terminations, step?overs, and accommodation zones. The pattern of faulting implies that other, previously undiscovered blind geothermal systems are likely in the Carson Sink. The gravity survey was completed near the end of this project. Thus, more thorough analysis of the data and potential locations of blind geothermal systems is planned for future work.
Lessons from (2+1)-dimensional quantum gravity
B. J. Schroers
2007-10-31T23:59:59.000Z
Proposals that quantum gravity gives rise to non-commutative spacetime geometry and deformations of Poincare symmetry are examined in the context of (2+1)-dimensional quantum gravity. The results are expressed in five lessons, which summarise how the gravitational constant, Planck's constant and the cosmological constant enter the non-commutative and non-cocommutative structures arising in (2+1)-dimensional quantum gravity. It is emphasised that the much studied bicrossproduct kappa-Poincare algebra does not arise directly in (2+1)-dimensional quantum gravity.
Ground Gravity Survey At Dixie Valley Geothermal Area (Allis...
Activity Details Location Dixie Valley Geothermal Area Exploration Technique Ground Gravity Survey Activity Date 1999 - 2000 Usefulness not indicated DOE-funding Unknown...
Ground Gravity Survey At Kilauea East Rift Geothermal Area (Broyles...
to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Kilauea East Rift Geothermal Area (Broyles, Et Al., 1979) Exploration...
Geologic interpretation of gravity and magnetic data in the Salida...
interpretation of gravity and magnetic data in the Salida region, Colorado Jump to: navigation, search OpenEI Reference LibraryAdd to library Report: Geologic interpretation of...
Bouguer gravity anomalies, depth to bedrock, and shallow temperature...
Bouguer gravity anomalies, depth to bedrock, and shallow temperature in the Humboldt House geothermal area, Pershing County, Nevada Jump to: navigation, search OpenEI Reference...
Ground Gravity Survey At Kilauea East Rift Geothermal Area (Leslie...
Details Location Kilauea East Rift Geothermal Area Exploration Technique Ground Gravity Survey Activity Date 1998 - 1998 Usefulness useful DOE-funding Unknown Exploration...
Integration of Full Tensor Gravity and ZTEM Passive Low Frequency...
Broader source: Energy.gov (indexed) [DOE]
Full Tensor Gravity and ZTEM Passive Low Frequency EM Instruments for Simultaneous Data Acquisition Scott Wieberg Bell Geospace, Inc. Track Name Project Officer: Ava Coy: Total...
Ground Gravity Survey At Neal Hot Springs Geothermal Area (U...
to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Neal Hot Springs Geothermal Area (U.S. Geothermal Inc., 2007) Exploration...
Ground Gravity Survey At Kilauea East Rift Geothermal Area (FURUMOTO...
Details Location Kilauea East Rift Geothermal Area Exploration Technique Ground Gravity Survey Activity Date 1974 - 1974 Usefulness useful DOE-funding Unknown Exploration...
Ground Gravity Survey At Mt Princeton Hot Springs Geothermal...
to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Mt Princeton Hot Springs Geothermal Area (Case, Et Al., 1984) Exploration...
Ground Gravity Survey At Baltazor Hot Springs Area (Isherwood...
to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Baltazor Hot Springs Area (Isherwood & Mabey, 1978) Exploration Activity...
Ground Gravity Survey At Roosevelt Hot Springs Geothermal Area...
Details Location Roosevelt Hot Springs Geothermal Area Exploration Technique Ground Gravity Survey Activity Date 1985 - 1985 Usefulness useful DOE-funding Unknown Exploration...
Ground Gravity Survey At Blue Mountain Geothermal Area (Fairbank...
Fairbank Engineering Ltd, 2003) Exploration Activity Details Location Blue Mountain Geothermal Area Exploration Technique Ground Gravity Survey Activity Date Usefulness not...
Lessons in quantum gravity from quantum field theory
Berenstein, David [Department of Physics, University of California at Santa Barbara, CA 93106 (United States); Institute for Advanced Study, School of Natural Science, Princeton, NJ 08540 (United States)
2010-12-07T23:59:59.000Z
This paper reviews advances in the understanding of quantum gravity based on field theory calculations in the AdS/CFT correspondence.
Ground Gravity Survey At Under Steamboat Springs Area (Warpinski...
Area (Warpinski, Et Al., 2004) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Under Steamboat Springs Area (Warpinski,...
Ground Gravity Survey At Valles Caldera - Sulphur Springs Geothermal...
Survey Activity Date - 1986 Usefulness not indicated DOE-funding Unknown Notes A computer program capable of two-dimensional modeling of gravity data was used in interpreting...
Summary of Session A6: Alternative Theories of Gravity
R. B. Mann
1998-03-13T23:59:59.000Z
This is a summary of the workshop A.6 on Alternative Theories of Gravity, prepared for the proceedings for the GR15 conference.
asymptotically safe gravity: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
at high energies. Elisa Manrique; Stefan Rechenberger; Frank Saueressig 2011-02-24 2 Fractal Spacetime Structure in Asymptotically Safe Gravity General Relativity & Quantum...
Ground Gravity Survey At Lake City Hot Springs Area (Warpinski...
Lake City Hot Springs Area (Warpinski, Et Al., 2004) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Lake City Hot...
Unification of Gravity and Electromagnetism II A Geometric Theory
Partha Ghose
2014-08-05T23:59:59.000Z
It is shown that unification of gravity and electromagnetism can be achieved using an affine non-symmetric connection $\\Gamma^\\lambda_{\\mu\
Ground Gravity Survey At San Francisco Volcanic Field Area (Warpinski...
geologically mapped the target area, obtained rock samples for age dating and mineral chemistry, performed gravity and magnetic surveys, and integrated these results to identify...
atmospheric gravity waves: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
gravity waves (AGWs). Satellite imagery shows evidence the characteristics of these waves. The favorable wave propagation conditions in 12;this region are illustrated 5...
Exercise protocols during short-radius centrifugation for artificial gravity
Edmonds, Jessica Leigh
2008-01-01T23:59:59.000Z
Long-duration spaceflight results in severe physiological deconditioning, threatening the success of interplanetary travel. Exercise combined with artificial gravity provided by centrifugation may be the comprehensive ...
Ground Gravity Survey At Long Valley Caldera Geothermal Area...
Battaglia, Et Al., 2003) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Long Valley Caldera Geothermal Area (Battaglia,...
Weeks Island gravity stable CO2 pilot: Final report
Johnston, J.R.; Perry, G.E.
1989-01-01T23:59:59.000Z
The Weeks Island ''S'' sand Reservoir B (''S'' RB) gravity-stable CO2 field test was completed during February 1988. Injection started in October 1978 and production began in January 1981 in this high-permeability, steeply-dipping sandstone reservoir. About 264,000 barrels of oil or 65 percent of the starting volume has been recovered. A 24-percent pore-volume slug of CO2 mixed with about six mole percent of natural gas (mostly methane) was injected at the start of the pilot. Since 1983, produced CO2 plus hydrocarbon gases have been recycled. CO2 usage statistics are 9.34 MCF/BO with recycle and 3.24 MCF/BO based on purchased CO2. Previous annual reports document the pilot design, implementation, and early results for the 1977 to June 1981 time period. This report is a review of early pilot history and a more detailed account of the post June 1981 results and overall interpretation. A reservoir-simulation history match of pilot performance plus core and log data from a 1983 swept-zone evaluation well are described in this report. A brief description of the production facility and an account of the corrosion control program are also included. 11 refs., 34 figs.
Gravity waves generated by sounds from Big Bang phase transitions
Kalaydzhyan, Tigran
2014-01-01T23:59:59.000Z
Inhomogeneities associated with the cosmological QCD and electroweak phase transitions produce hydrodynamical perturbations, longitudinal sounds and rotations. It has been demonstrated numerically by Hindmarsh et al. that the sounds produce gravity waves (GW), and that this process does continue well after the phase transition is over. We further introduce a long period of the so-called inverse acoustic cascade, between the UV momentum scale at which the sound is originally produced and the IR scale at which GW is generated. It can be described by the Boltzmann equation, possessing stationary power and self-similar time-dependent solutions. If the sound dispersion law allows one-to-two sound decays, the exponent of the power solution is large and a strong amplification of the sound amplitude (limited only by the total energy) takes place. Alternative scenario dominated by sound scattering leads to smaller indices and much smaller IR sound amplitude. We also point out that two on shell phonons can produce a gr...
Microscopic quantum structure of black hole and vacuum versus quantum statistical origin of gravity
Shun-Jin Wang
2014-10-28T23:59:59.000Z
The Planckon densely piled model of vacuum is proposed. Based on this model, the microscopic quantum structure of Schwarzschild black hole and quantum statistical origin of its gravity are studied. The cutoff of black hole horizon leads to Casimir effect inside the horizon. This effect makes the inside vacuum has less zero quantum fluctuation energy than that of outside vacuum and the spin 1/2 radiation hole excitations are resulted inside the horizon. The mean energy of the radiation hole excitations is related to the temperature decrease of the Hawking-Unruh type by the period law of the Fermion temperature greens function and a temperature difference as well as gravity are created on the horizon. A dual relation of the gravity potentials between inside and outside regions of the black hole is found. An attractor behaviour of the horizon surface is unveiled. The gravity potential inside the black hole is linear in radial coordinate and no singularity exists at the origin of the black hole, in contrast to the conventional conjecture. All the particles absorbed by the black hole have fallen down to the horizon and converted into spin 1/2 radiation quanta with the mean energy related to the Hawking-Unruh temperature, the thermodynamic equilibrium and the mechanical balance make the radiation quanta be tightly bound in the horizon. The gravitation mass $2M$ and physical mass $M$ of the black hole are calculated. The calculated entropy of the black hole is well consistent with Hawking. Outside the horizon, there exist thermodynamic non-equilibrium and mechanical non-balance which lead to an outward centrifugal energy flow and an inward gravitation energy flow. The lost vacuum energy in the negative gravitation potential region has been removed to the black hole surface to form a spherical Planckon shell with the thickness of Planckon diameter so that energy conservation is guaranteed.
The JPL lunar gravity field to spherical harmonic degree 660 from the GRAIL Primary Mission
Konopliv, Alex S.
The lunar gravity field and topography provide a way to probe the interior structure of the Moon. Prior to the Gravity Recovery and Interior Laboratory (GRAIL) mission, knowledge of the lunar gravity was limited mostly to ...
Compositional modeling of threephase flow with gravity using higherorder finite element methods
Firoozabadi, Abbas
Compositional modeling of threephase flow with gravity using higherorder finite element methods using higherorder finite element methods. Gravity poses complications in modeling multiphase processes flow with gravity using higherorder finite element methods, Water Resour. Res., 47, W05511, doi:10
Eddy diffusivities of inertial particles under gravity
Marco Martins Afonso; Andrea Mazzino; Paolo Muratore-Ginanneschi
2011-03-29T23:59:59.000Z
The large-scale/long-time transport of inertial particles of arbitrary mass density under gravity is investigated by means of a formal multiple-scale perturbative expansion in the scale-separation parametre between the carrier flow and the particle concentration field. The resulting large-scale equation for the particle concentration is determined, and is found to be diffusive with a positive-definite eddy diffusivity. The calculation of the latter tensor is reduced to the resolution of an auxiliary differential problem, consisting of a coupled set of two differential equations in a (6+1)-dimensional coordinate system (3 space coordinates plus 3 velocity coordinates plus time). Although expensive, numerical methods can be exploited to obtain the eddy diffusivity, for any desirable non-perturbative limit (e.g. arbitrary Stokes and Froude numbers). The aforementioned large-scale equation is then specialized to deal with two different relevant perturbative limits: i) vanishing of both Stokes time and sedimenting particle velocity; ii) vanishing Stokes time and finite sedimenting particle velocity. Both asymptotics lead to a greatly simplified auxiliary differential problem, now involving only space coordinates and thus easy to be tackled by standard numerical techniques. Explicit, exact expressions for the eddy diffusivities have been calculated, for both asymptotics, for the class of parallel flows, both static and time-dependent. This allows us to investigate analytically the role of gravity and inertia on the diffusion process by varying relevant features of the carrier flow, as e.g. the form of its temporal correlation function. Our results exclude a universal role played by gravity and inertia on the diffusive behaviour: regimes of both enhanced and reduced diffusion may exist, depending on the detailed structure of the carrier flow.
Perturbations of Nested Branes With Induced Gravity
Fulvio Sbisa'; Kazuya Koyama
2014-06-06T23:59:59.000Z
We study the behaviour of weak gravitational fields in models where a 4D brane is embedded inside a 5D brane equipped with induced gravity, which in turn is embedded in a 6D spacetime. We consider a specific regularization of the branes internal structures where the 5D brane can be considered thin with respect to the 4D one. We find exact solutions corresponding to pure tension source configurations on the thick 4D brane, and study perturbations at first order around these background solutions. To perform the perturbative analysis, we adopt a bulk-based approach and we express the equations in terms of gauge invariant and master variables using a 4D scalar-vector-tensor decomposition. We then propose an ansatz on the behaviour of the perturbation fields when the thickness of the 4D brane goes to zero, which corresponds to configurations where gravity remains finite everywhere in the thin limit of the 4D brane. We study the equations of motion using this ansatz, and show that they give rise to a consistent set of differential equations in the thin limit, from which the details of the internal structure of the 4D brane disappear. We conclude that the thin limit of the "ribbon" 4D brane inside the (already thin) 5D brane is well defined (at least when considering first order perturbations around pure tension configurations), and that the gravitational field on the 4D brane remains finite in the thin limit. We comment on the crucial role of the induced gravity term on the 5D brane.
Wave Packets Propagation in Quantum Gravity
Kourosh Nozari; S. H. Mehdipour
2005-07-03T23:59:59.000Z
Wave packet broadening in usual quantum mechanics is a consequence of dispersion behavior of the medium which the wave propagates in it. In this paper, we consider the problem of wave packet broadening in the framework of Generalized Uncertainty Principle(GUP) of quantum gravity. New dispersion relations are derived in the context of GUP and it has been shown that there exists a gravitational induced dispersion which leads to more broadening of the wave packets. As a result of these dispersion relations, a generalized Klein-Gordon equation is obtained and its interpretation is given.
Conservation of energy and Gauss Bonnet gravity
Christophe Real
2007-11-07T23:59:59.000Z
It is shown how can be made the classification of all tensors constructed from the Riemann tensor that verify the conservation of gravitational energy momentum. More precisely we explain that there exists a unique tensor of degree n in the Riemann tensor and its contractions that verifies the conservation of energy. We show that this tensor, only because it obeys this degree n structure as well as energy conservation, two facts which are true in all dimensions, verifies in dimension 2n this striking particularity of being Euler gravity. We stick here to the case n=2 but explain briefly why the general case is similar.
Loop quantum gravity - a short review
Sahlmann, Hanno
2010-01-01T23:59:59.000Z
In this article we review the foundations and the present status of loop quantum gravity. It is short and relatively non-technical, the emphasis is on the ideas, and the flavor of the techniques. In particular, we describe the kinematical quantization and the implementation of the Hamilton constraint, as well as the quantum theory of black hole horizons, semiclassical states, and matter propagation. Spin foam models and loop quantum cosmology are mentioned only in passing, as these will be covered in separate reviews to be published alongside this one.
Gravity with a dynamical preferred frame
Ted Jacobson; David Mattingly
2001-06-02T23:59:59.000Z
We study a generally covariant model in which local Lorentz invariance is broken "spontaneously" by a dynamical unit timelike vector field $u^a$---the "aether". Such a model makes it possible to study the gravitational and cosmological consequences of preferred frame effects, such as ``variable speed of light" or high frequency dispersion, while preserving a generally covariant metric theory of gravity. In this paper we restrict attention to an action for an effective theory of the aether which involves only the antisymmetrized derivative $\
Cosmological Solutions of Emergent Noncommutative Gravity
Klammer, Daniela; Steinacker, Harold [Fakultaet fuer Physik, Universitaet Wien, A-1090 Wien (Austria)
2009-06-05T23:59:59.000Z
Matrix models of the Yang-Mills type lead to an emergent gravity theory, which does not require fine-tuning of a cosmological constant. We find cosmological solutions of the Friedmann-Robertson-Walker type. They generically have a big bounce, and an early inflationlike phase with graceful exit. The mechanism is purely geometrical; no ad hoc scalar fields are introduced. The solutions are stabilized through vacuum fluctuations and are thus compatible with quantum mechanics. This leads to a Milne-like universe after inflation, which appears to be in remarkably good agreement with observation and may provide an alternative to standard cosmology.
Duality and KPZ in Liouville Quantum Gravity
Bertrand Duplantier; Scott Sheffield
2009-01-02T23:59:59.000Z
We present a (mathematically rigorous) probabilistic and geometrical proof of the KPZ relation between scaling exponents in a Euclidean planar domain D and in Liouville quantum gravity. It uses the properly regularized quantum area measure d\\mu_\\gamma=\\epsilon^{\\gamma^2/2} e^{\\gamma h_\\epsilon(z)}dz, where dz is Lebesgue measure on D, \\gamma is a real parameter, 0\\leq \\gamma 2 is shown to be related to the quantum measure d\\mu_{\\gamma'}, \\gamma' < 2, by the fundamental duality \\gamma\\gamma'=4.
Gravity duals for non-relativistic CFTs
Koushik Balasubramanian; John McGreevy
2008-08-01T23:59:59.000Z
We attempt to generalize the AdS/CFT correspondence to non-relativistic conformal field theories which are invariant under Galilean transformations. Such systems govern ultracold atoms at unitarity, nucleon scattering in some channels, and more generally, a family of universality classes of quantum critical behavior. We construct a family of metrics which realize these symmetries as isometries. They are solutions of gravity with negative cosmological constant coupled to pressureless dust. We discuss realizations of the dust, which include a bulk superconductor. We develop the holographic dictionary and compute some two-point correlators. A strange aspect of the correspondence is that the bulk geometry has two extra noncompact dimensions.
Thermodynamics of 5D dilaton-gravity
Megias, E. [Institute for Theoretical Physics, University of Heidelberg (Germany); Instituto de Fisica Teorica CSIC-UAM, Universidad Autonoma de Madrid (Spain)
2011-05-23T23:59:59.000Z
We calculate the free energy, spatial string tension and Polyakov loop of the gluon plasma using the dilaton potential of Ref. [1] in the dilaton-gravity theory of AdS/QCD. The free energy is computed from the Black Hole solutions of the Einstein equations in two ways: first, from the Bekenstein-Hawking proportionality of the entropy with the area of the horizon, and secondly from the Page-Hawking computation of the free energy. The finite temperature behaviour of the spatial string tension and Polyakov loop follow from the corresponding string theory in AdS{sub 5}. Comparison with lattice data is made.
Holographic renormalization of new massive gravity
Alishahiha, Mohsen [School of Physics, Institute for Research in Fundamental Sciences (IPM), P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of); Naseh, Ali [School of Physics, Institute for Research in Fundamental Sciences (IPM), P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of); Department of Physics, Sharif University of Technology, P.O. Box 11365-9161, Tehran (Iran, Islamic Republic of)
2010-11-15T23:59:59.000Z
We study holographic renormalization for three-dimensional new massive gravity. By studying the general falloff conditions for the metric allowed by the model at infinity, we show that at the critical point where the central charges of the dual conformal field theory (CFT) are zero, it contains a leading logarithmic behavior. In the context of AdS/CFT correspondence it can be identified as a source for an irrelevant operator in the dual CFT. The presence of the logarithmic falloff may be interpreted as the fact that the dual CFT would be a logarithmic conformal field theory.
Gravity dual of spatially modulated phase
Nakamura, Shin [Department of Physics, Kyoto University, Kyoto 606-8502 (Japan); Ooguri, Hirosi [California Institute of Technology, Pasadena, California 91125 (United States); IPMU, University of Tokyo, Kashiwa 277-8586 (Japan); Park, Chang-Soon [California Institute of Technology, Pasadena, California 91125 (United States)
2010-02-15T23:59:59.000Z
We show that the five-dimensional Maxwell theory with the Chern-Simons term is tachyonic in the presence of a constant electric field. When coupled to gravity, a sufficiently large Chern-Simons coupling causes instability of the Reissner-Nordstroem black holes in anti-de Sitter space. The instability happens only at nonvanishing momenta, suggesting a spatially modulated phase in the holographically dual quantum field theory in (3+1) dimensions, with spontaneous current generation in a helical configuration. The three-charge extremal black hole in the type IIB superstring theory on AdS{sub 5}xS{sup 5} barely satisfies the stability condition.
Apparent horizon in fluid-gravity duality
Booth, Ivan; Heller, Michal P.; Plewa, Grzegorz; Spalinski, Michal [Department of Mathematics and Statistics, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, A1C 5S7 (Canada); Instituut voor Theoretische Fysica, Universiteit van Amsterdam, Science Park 904, 1090 GL Amsterdam (Netherlands); Soltan Institute for Nuclear Studies, Hoza 69, 00-681 Warsaw (Poland); Soltan Institute for Nuclear Studies, Hoza 69, 00-681 Warsaw (Poland) and Physics Department, University of Bialystok, 15-424 Bialystok (Poland)
2011-05-15T23:59:59.000Z
This article develops a computational framework for determining the location of boundary-covariant apparent horizons in the geometry of conformal fluid-gravity duality in arbitrary dimensions. In particular, it is shown up to second order and conjectured to hold to all orders in the gradient expansion that there is a unique apparent horizon which is covariantly expressible in terms of fluid velocity, temperature, and boundary metric. This leads to the first explicit example of an entropy current defined by an apparent horizon and opens the possibility that in the near-equilibrium regime there is preferred foliation of apparent horizons for black holes in asymptotically anti-de Sitter spacetimes.
Seven-dimensional gravity with topological terms
Lue, H. [China Economics and Management Academy Central, University of Finance and Economics, Beijing 100081 (China); Institute for Advanced Study, Shenzhen University, Nanhai Ave 3688, Shenzhen 518060 (China); Pang Yi [Key Laboratory of Frontiers in Theoretical Physics Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190 (China)
2010-04-15T23:59:59.000Z
We construct new seven-dimensional gravity by adding two topological terms to the Einstein-Hilbert action. For a certain choice of the coupling constants, these terms exist naturally in seven-dimensional gauged supergravity from the S{sup 4} reduction of eleven-dimensional supergravity with the R{sup 4} corrections. We derive the full set of the equations of motion. We find that the static spherically-symmetric black holes are unmodified by the topological terms. We obtain squashed AdS{sub 7}, and also squashed seven spheres and Q{sup 111} spaces in Euclidean signature.
Fractal Spacetime Structure in Asymptotically Safe Gravity
O. Lauscher; M. Reuter
2005-08-26T23:59:59.000Z
Four-dimensional Quantum Einstein Gravity (QEG) is likely to be an asymptotically safe theory which is applicable at arbitrarily small distance scales. On sub-Planckian distances it predicts that spacetime is a fractal with an effective dimensionality of 2. The original argument leading to this result was based upon the anomalous dimension of Newton's constant. In the present paper we demonstrate that also the spectral dimension equals 2 microscopically, while it is equal to 4 on macroscopic scales. This result is an exact consequence of asymptotic safety and does not rely on any truncation. Contact is made with recent Monte Carlo simulations.
Confronting Dilaton-exchange gravity with experiments
H. V. Klapdor-Kleingrothaus; H. Päs; U. Sarkar
2000-08-16T23:59:59.000Z
We study the experimental constraints on theories, where the equivalence principle is violated by dilaton-exchange contributions to the usual graviton-exchange gravity. We point out that in this case it is not possible to have any CPT violation and hence there is no constraint from the CPT violating measurements in the $K-$system. The most stringent bound is obtained from the $K_L - K_S$ mass difference. In contrast, neither neutrino oscillation experiments nor neutrinoless double beta decay imply significant constraints.
Gamma Ray Burst Neutrinos Probing Quantum Gravity
M. C. Gonzalez-Garcia; F. Halzen
2006-11-28T23:59:59.000Z
Very high energy, short wavelength, neutrinos may interact with the space-time foam predicted by theories of quantum gravity. They would propagate like light through a crystal lattice and be delayed, with the delay depending on the energy. This will appear to the observer as a violation of Lorenz invariance. Back of the envelope calculations imply that observations of neutrinos produced by gamma ray bursts may reach Planck-scale sensitivity. We revisit the problem considering two essential complications: the imprecise timing of the neutrinos associated with their poorly understood production mechanism in the source and the indirect nature of their energy measurement made by high energy neutrino telescopes.
Gravitational lensing in metric theories of gravity
M. Sereno
2003-01-15T23:59:59.000Z
Gravitational lensing in metric theories of gravity is discussed. I introduce a generalized approximate metric element, inclusive of both post-post-Newtonian (ppN) contributions and gravito-magnetic field. Following Fermat's principle and standard hyphoteses, I derive the time delay function and deflection angle caused by an isolated mass distribution. Several astrophysical systems are considered. In most of the cases, the gravito-magnetic correction offers the best perspectives for an observational detection. Actual measurements distinguish only marginally different metric theories one from another.
Ground Gravity Survey | Open Energy Information
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 Home5b9fcbce19 No revision hasInformation Earth's Heat Jump to:Photon Place:Net Jump to: navigation,2004)EnergyGround Gravity
Periodic and quasiperiodic motions of many particles falling in a viscous fluid
Gruca, Marta; Ekiel-Jezewska, Maria L
2015-01-01T23:59:59.000Z
Dynamics of regular clusters of many non-touching particles falling under gravity in a viscous fluid at low Reynolds number are analysed within the point-particle model. Evolution of two families of particle configurations is determined: 2 or 4 regular horizontal polygons (called `rings') centred above or below each other. Two rings fall together and periodically oscillate. Four rings usually separate from each other with chaotic scattering. For hundreds of thousands of initial configurations, a map of the cluster lifetime is evaluated, where the long-lasting systems are centred around periodic solutions for the relative motions. The results illustrate that the existence of periodic solutions is essential for clustering of many sedimenting particles.
E-Print Network 3.0 - absolute gravity measurements Sample Search...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
gravity measurements Search Powered by Explorit Topic List Advanced Search Sample search results for: absolute gravity measurements Page: << < 1 2 3 4 5 > >> 1 PROCEEDINGS,...
Gravity effects on partially premixed flames: an experimental-numerical investigation
Aggarwal, Suresh K.
Gravity effects on partially premixed flames: an experimental-numerical investigation Andrew J and interactions between the various reaction zones are strongly influenced by gravity. The flames widen
E-Print Network 3.0 - artificial gravity reveals Sample Search...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
line is required. This value is computed from the surface gravity... focuses on different error sources, which influence the gravity ... Source: Schuh, Harald - Institut fr...
Inverted gravity, not inverted shape impairs biological motion perception
Troje, Nikolaus
Inverted gravity, not inverted shape impairs biological motion perception Nikolaus Trojetroje. Scrambling should therefore impair perception even more than inversion. Upright and inverted scrambled motion). Is the cause of the inversion effect inverted gravity? If this is the case upright scrambled motion should
Remarks on Pure Spin Connection Formulations of Gravity
Riccardo Capovilla; Ted Jacobson
1992-07-21T23:59:59.000Z
In the derivation of a pure spin connection action functional for gravity two methods have been proposed. The first starts from a first order lagrangian formulation, the second from a hamiltonian formulation. In this note we show that they lead to identical results for the specific cases of pure gravity with or without a cosmological constant.
Mapping crustal thickness using marine gravity data: Methods and uncertainties
Müller, Dietmar
of petroleum systems within passive margins. However, direct measurements of crustal thickness are sparse geophysical data, to estimate crustal thickness. We evaluated alternative gravity inversion methodol- ogies, but economic considerations make gravity modeling a more practical approach for mapping crustal thickness over
Phenomenological Quantum Gravity: the birth of a new frontier?
R. Aloisio; P. Blasi; A. Galante; P. L. Ghia; A. F. Grillo; F. Mendez
2005-02-01T23:59:59.000Z
In the last years a general consensus has emerged that, contrary to intuition, quantum-gravity effects may have relevant consequences for the propagation and interaction of high energy particles. This has given birth to the field of ``Phenomenological Quantum Gravity'' We review some of the aspects of this new, very exciting frontier of Physics.
Constraints on Dark Energy Models from Weak Gravity Conjecture
Ximing Chen; Jie Liu; Yungui Gong
2008-06-15T23:59:59.000Z
We study the constraints on the dark energy model with constant equation of state parameter $w=p/\\rho$ and the holographic dark energy model by using the weak gravity conjecture. The combination of weak gravity conjecture and the observational data gives $wenergy model realized by a scalar field is in swampland.
Gravity waves excited by jets: Propagation versus generation R. Plougonven
Plougonven, Riwal
Gravity waves excited by jets: Propagation versus generation R. Plougonven School of Mathematics imposed by the generation mechanism. In proceeding so, effects due to the propagation of the waves through simulations demonstrate that the propagation of inertia-gravity waves through horizontal deformation
Perturbations of Nested Branes With Induced Gravity
Sbisa', Fulvio
2014-01-01T23:59:59.000Z
We study the behaviour of weak gravitational fields in models where a 4D brane is embedded inside a 5D brane equipped with induced gravity, which in turn is embedded in a 6D spacetime. We consider a specific regularization of the branes internal structures where the 5D brane can be considered thin with respect to the 4D one. We find exact solutions corresponding to pure tension source configurations on the thick 4D brane, and study perturbations at first order around these background solutions. To perform the perturbative analysis, we adopt a bulk-based approach and we express the equations in terms of gauge invariant and master variables using a 4D scalar-vector-tensor decomposition. We then propose an ansatz on the behaviour of the perturbation fields when the thickness of the 4D brane goes to zero, which corresponds to configurations where gravity remains finite everywhere in the thin limit of the 4D brane. We study the equations of motion using this ansatz, and show that they give rise to a consistent set...
A dynamical inconsistency of Horava gravity
Henneaux, Marc [Universite Libre de Bruxelles and International Solvay Institutes, ULB-Campus Plaine CP231, 1050 Brussels (Belgium); Centro de Estudios Cientificos (CECS), Casilla 1469, Valdivia (Chile); Kleinschmidt, Axel; Lucena Gomez, Gustavo [Universite Libre de Bruxelles and International Solvay Institutes, ULB-Campus Plaine CP231, 1050 Brussels (Belgium)
2010-03-15T23:59:59.000Z
The dynamical consistency of the nonprojectable version of Horava gravity is investigated by focusing on the asymptotically flat case. It is argued that for generic solutions of the constraint equations the lapse must vanish asymptotically. We then consider particular values of the coupling constants for which the equations are tractable and in that case we prove that the lapse must vanish everywhere--and not only at infinity. Put differently, the Hamiltonian constraints are generically all second-class. We then argue that the same feature holds for generic values of the couplings, thus revealing a physical inconsistency of the theory. In order to cure this pathology, one might want to introduce further constraints but the resulting theory would then lose much of the appeal of the original proposal by Horava. We also show that there is no contradiction with the time-reparametrization invariance of the action, as this invariance is shown to be a so-called 'trivial gauge symmetry' in Horava gravity, hence with no associated first-class constraints.
Analogue model for quantum gravity phenomenology
Silke Weinfurtner; Stefano Liberati; Matt Visser
2005-11-18T23:59:59.000Z
So called "analogue models" use condensed matter systems (typically hydrodynamic) to set up an "effective metric" and to model curved-space quantum field theory in a physical system where all the microscopic degrees of freedom are well understood. Known analogue models typically lead to massless minimally coupled scalar fields. We present an extended "analogue space-time" programme by investigating a condensed-matter system - in and beyond the hydrodynamic limit - that is in principle capable of simulating the massive Klein-Gordon equation in curved spacetime. Since many elementary particles have mass, this is an essential step in building realistic analogue models, and an essential first step towards simulating quantum gravity phenomenology. Specifically, we consider the class of two-component BECs subject to laser-induced transitions between the components, and we show that this model is an example for Lorentz invariance violation due to ultraviolet physics. Furthermore our model suggests constraints on quantum gravity phenomenology in terms of the "naturalness problem" and "universality issue".
Bigravity and Lorentz-violating massive gravity
Blas, D.; Garriga, J. [ICC, Departament de Fisica Fonamental, Universitat de Barcelona, Diagonal 647, 08028 Barcelona (Spain); Deffayet, C. [APC, Batiment Condorcet, 10 rue Alice Domont et Leonie Duquet, 75205 Paris Cedex 13 (France); GReCO/IAP, 98 bis Boulevard Arago, 75014 Paris (France)
2007-11-15T23:59:59.000Z
Bigravity is a natural arena where a nonlinear theory of massive gravity can be formulated. If the interaction between the metrics f and g is nonderivative, spherically symmetric exact solutions can be found. At large distances from the origin, these are generically Lorentz-breaking bi-flat solutions (provided that the corresponding vacuum energies are adjusted appropriately). The spectrum of linearized perturbations around such backgrounds contains a massless as well as a massive graviton, with two physical polarizations each. There are no propagating vectors or scalars, and the theory is ghost free (as happens with certain massive gravities with explicit breaking of Lorentz invariance). At the linearized level, corrections to general relativity are proportional to the square of the graviton mass, and so there is no van Dam-Veltam-Zakharov discontinuity. Surprisingly, the solution of linear theory for a static spherically symmetric source does not agree with the linearization of any of the known exact solutions. The latter coincide with the standard Schwarzschild-(anti)-de Sitter solutions of general relativity, with no corrections at all. Another interesting class of solutions is obtained where f and g are proportional to each other. The case of bi-de Sitter solutions is analyzed in some detail.
Non-trivial 2+1-Dimensional Gravity
D. R. Grigore; G. Scharf
2010-08-07T23:59:59.000Z
We analyze 2+1-dimensional gravity in the framework of quantum gauge theory. We find that Einstein gravity has a trivial physical subspace which reflects the fact that the classical solution in empty space is flat. Therefore we study massive gravity which is not trivial. In the limit of vanishing graviton mass we obtain a non-trivial massless theory different from Einstein gravity. We derive the interaction from descent equations and obtain the cosmological topologically massive gravity. However, in addition to Einstein and Chern-Simons coupling we need coupling to fermionic ghost and anti-ghost fields and to a vector-graviton field with the same mass as the graviton.
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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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: VegetationEquipment Surfaces andMapping the NanoscaleMechanical BehaviorSummerwelcome day of event
Qiang, Li-E
2015-01-01T23:59:59.000Z
High precision Superconductivity Gravity Gradiometers (SGG) are powerful tools for relativistic experiments. In this paper, we work out the tidal signals in non-dynamical Chern-Simons modified gravity, which could be measured by orbiting SGGs around Earth. We find that, with proper orientations of multi-axes SGGs, the tidal signals from the Chern-Simons modification can be isolated in the combined data of different axes. Furthermore, for three-axes SGGs, such combined data is the trace of the total tidal matrix, which is invariant under the rotations of SGG axes and thus free from axis pointing errors. Following nearly circular orbits, the tests of the parity-violating Chern-Simons modification and the measurements of the gravitomagnetic sector in parity-conserving metric theories can be carried out independently in the same time. A first step analysis on noise sources is also included.
Li-E Qiang; Peng Xu
2015-02-16T23:59:59.000Z
High precision Superconductivity Gravity Gradiometers (SGG) are powerful tools for relativistic experiments. In this paper, we work out the tidal signals in non-dynamical Chern-Simons modified gravity, which could be measured by orbiting SGGs around Earth. We find that, with proper orientations of multi-axes SGGs, the tidal signals from the Chern-Simons modification can be isolated in the combined data of different axes. Furthermore, for three-axes SGGs, such combined data is the trace of the total tidal matrix, which is invariant under the rotations of SGG axes and thus free from axis pointing errors. Following nearly circular orbits, the tests of the parity-violating Chern-Simons modification and the measurements of the gravitomagnetic sector in parity-conserving metric theories can be carried out independently in the same time. A first step analysis on noise sources is also included.
Aharon Davidson; Tomer Ygael
2014-10-22T23:59:59.000Z
A gravity-anti-gravity (GaG) odd linear dilaton action offers an eternal inflation evolution governed by the unified (cosmological constant plus radiation) equation of state $\\rho-3P=4\\Lambda$. At the mini superspace level, a 'two-particle' variant of the no-boundary proposal, notably 'one-particle' energy dependent, is encountered. While a GaG-odd wave function can only host a weak Big Bang boundary condition, albeit for any $k$, a strong Big Bang boundary condition requires a GaG-even entangled wave function, and singles out $k=0$ flat space. The locally most probable values for the cosmological scale factor and the dilaton field form a grid $\\{a^2,a\\phi\\}\\sim\\sqrt{4n_1+1}\\pm\\sqrt{4n_2+1}$.
Semiclassical approximation to supersymmetric quantum gravity
Kiefer, Claus; Lueck, Tobias; Moniz, Paulo [Institut fuer Theoretische Physik, Universitaet zu Koeln, Zuelpicher Strasse 77, 50937 Cologne (Germany); Astronomy Unit, School of Mathematical Sciences, Queen Mary College, University of London, Mile End Road, London E1 4NS (United Kingdom)
2005-08-15T23:59:59.000Z
We develop a semiclassical approximation scheme for the constraint equations of supersymmetric canonical quantum gravity. This is achieved by a Born-Oppenheimer type of expansion, in analogy to the case of the usual Wheeler-DeWitt equation. The formalism is only consistent if the states at each order depend on the gravitino field. We recover at consecutive orders the Hamilton-Jacobi equation, the functional Schroedinger equation, and quantum gravitational correction terms to this Schroedinger equation. In particular, the following consequences are found: (i) the Hamilton-Jacobi equation and therefore the background spacetime must involve the gravitino, (ii) a (many-fingered) local time parameter has to be present on super Riem {sigma} (the space of all possible tetrad and gravitino fields) (iii) quantum supersymmetric gravitational corrections affect the evolution of the very early Universe. The physical meaning of these equations and results, in particular, the similarities to and differences from the pure bosonic case, are discussed.
Holographic Fluids with Vorticity and Analogue Gravity
Robert G. Leigh; Anastasios C. Petkou; P. Marios Petropoulos
2012-05-28T23:59:59.000Z
We study holographic three-dimensional fluids with vorticity in local equilibrium and discuss their relevance to analogue gravity systems. The Fefferman-Graham expansion leads to the fluid's description in terms of a comoving and rotating Papapetrou-Randers frame. A suitable Lorentz transformation brings the fluid to the non-inertial Zermelo frame, which clarifies its interpretation as moving media for light/sound propagation. We apply our general results to the Lorentzian Kerr-AdS_4 and Taub-NUT-AdS_4 geometries that describe fluids in cyclonic and vortex flows respectively. In the latter case we associate the appearance of closed timelike curves to analogue optical horizons. In addition, we derive the classical rotational Hall viscosity of three-dimensional fluids with vorticity. Our formula remarkably resembles the corresponding result in magnetized plasmas.
QCD thermodynamics using five-dimensional gravity
Megias, E.; Veschgini, K. [Institute for Theoretical Physics, University of Heidelberg (Germany); Pirner, H. J. [Institute for Theoretical Physics, University of Heidelberg (Germany); Max Planck Institute for Nuclear Physics, Heidelberg (Germany)
2011-03-01T23:59:59.000Z
We calculate the critical temperature and free energy of the gluon plasma using the dilaton potential [B. Galow, E. Megias, J. Nian, and H. J. Pirner, Nucl. Phys. B834, 330 (2010).] in the gravity theory of anti-de Sitter/QCD. The finite temperature observables are calculated in two ways: first, from the Page-Hawking computation of the free energy, and secondly using the Bekenstein-Hawking proportionality of the entropy with the area of the horizon. Renormalization is well defined, because the T=0 theory has asymptotic freedom. We further investigate the change of the critical temperature with the number of flavors induced by the change of the running coupling constant in the quenched theory. The finite temperature behavior of the speed of sound, spatial string tension and vacuum expectation value of the Polyakov loop follow from the corresponding string theory in AdS{sub 5}.
Bergshoeff, Eric A.; Hohm, Olaf [Centre for Theoretical Physics, University of Groningen, Nijenborgh 4, 9747 AG Groningen (Netherlands); Townsend, Paul K. [Department of Applied Mathematics and Theoretical Physics, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge, CB3 0WA (United Kingdom)
2009-06-15T23:59:59.000Z
We explore the space of static solutions of the recently discovered three-dimensional 'new massive gravity' (NMG), allowing for either sign of the Einstein-Hilbert term and a cosmological term parametrized by a dimensionless constant {lambda}. For {lambda}=-1 we find black hole solutions asymptotic (but not isometric) to the unique (anti) de Sitter [(A)dS] vacuum, including extremal black holes that interpolate between this vacuum and (A)dS{sub 2}xS{sup 1}. We also investigate unitarity of linearized NMG in (A)dS vacua. We find unitary theories for some dS vacua, but (bulk) unitarity in AdS implies negative central charge of the dual conformal field theories (CFT), except for {lambda}=3 where the central charge vanishes and the bulk gravitons are replaced by 'massive photons'. A similar phenomenon is found in the massless limit of NMG, for which the linearized equations become equivalent to Maxwell's equations.
Gravity dual of metastable dynamical supersymmetry breaking
DeWolfe, Oliver [Department of Physics, 390 UCB, University of Colorado, Boulder, Colorado 80309 (United States); Kachru, Shamit; Mulligan, Michael [Department of Physics and SLAC, Stanford University, Stanford, California 94305/94309 (United States)
2008-03-15T23:59:59.000Z
Metastable, supersymmetry-breaking configurations can be created in flux geometries by placing antibranes in warped throats. Via gauge/gravity duality, such configurations should have an interpretation as supersymmetry-breaking states in the dual field theory. In this paper, we perturbatively determine the asymptotic supergravity solutions corresponding to D3-brane probes placed at the tip of the cascading warped deformed conifold geometry, which is dual to an SU(N+M)xSU(N) gauge theory. The backreaction of the antibranes has the effect of introducing imaginary anti-self-dual flux, squashing the compact part of the space and forcing the dilaton to run. Using the generalization of holographic renormalization to cascading geometries, we determine the expectation values of operators in the dual field theory in terms of the asymptotic values of the supergravity fields.
Brane f(R) gravity cosmologies
Balcerzak, Adam; DaPbrowski, Mariusz P. [Institute of Physics, University of Szczecin, Wielkopolska 15, 70-451 Szczecin (Poland)
2010-06-15T23:59:59.000Z
By the application of the generalized Israel junction conditions we derive cosmological equations for the fourth-order f(R) brane gravity and study their cosmological solutions. We show that there exists a nonstatic solution which describes a four-dimensional de Sitter (dS{sub 4}) brane embedded in a five-dimensional anti-de Sitter (AdS{sub 5}) bulk for a vanishing Weyl tensor contribution. On the other hand, for the case of a nonvanishing Weyl tensor contribution, there exists a static brane solution only. We claim that in order to get some more general nonstatic f(R) brane configurations, one needs to admit a dynamical matter energy-momentum tensor in the bulk rather than just a bulk cosmological constant.
Flat Spacetime Vacuum in Loop Quantum Gravity
A. Mikovic
2004-04-06T23:59:59.000Z
We construct a state in the loop quantum gravity theory with zero cosmological constant, which should correspond to the flat spacetime vacuum solution. This is done by defining the loop transform coefficients of a flat connection wavefunction in the holomorphic representation which satisfies all the constraints of quantum General Relativity and it is peaked around the flat space triads. The loop transform coefficients are defined as spin foam state sum invariants of the spin networks embedded in the spatial manifold for the SU(2) quantum group. We also obtain an expression for the vacuum wavefunction in the triad represntation, by defining the corresponding spin networks functional integrals as SU(2) quantum group state sums.
Gravitational Waves in Ghost Free Bimetric Gravity
Morteza Mohseni
2012-11-15T23:59:59.000Z
We obtain a set of exact gravitational wave solutions for the ghost free bimetric theory of gravity. With a flat reference metric, the theory admits the vacuum Brinkmann plane wave solution for suitable choices of the coefficients of different terms in the interaction potential. An exact gravitational wave solution corresponding to a massive scalar mode is also admitted for arbitrary choice of the coefficients with the reference metric being proportional to the spacetime metric. The proportionality factor and the speed of the wave are calculated in terms of the parameters of the theory. We also show that a F(R) extension of the theory admits similar solutions but in general is plagued with ghost instabilities.
A length operator for canonical quantum gravity
T. Thiemann
1996-06-29T23:59:59.000Z
We construct an operator that measures the length of a curve in four-dimensional Lorentzian vacuum quantum gravity. We work in a representation in which a $SU(2)$ connection is diagonal and it is therefore surprising that the operator obtained after regularization is densely defined, does not suffer from factor ordering singularities and does not require any renormalization. We show that the length operator admits self-adjoint extensions and compute part of its spectrum which like its companions, the volume and area operators already constructed in the literature, is purely discrete and roughly is quantized in units of the Planck length. The length operator contains full and direct information about all the components of the metric tensor which faciliates the construction of a new type of weave states which approximate a given classical 3-geometry.
Bi-metric Gravity and "Dark Matter"
I. T. Drummond
2000-08-18T23:59:59.000Z
We present a bi-metric theory of gravity containing a length scale of galactic size. For distances less than this scale the theory satisfies the standard tests of General Relativity. For distances greater than this scale the theory yields an effective gravitational constant much larger than the locally observed value of Newton's constant. The transition from one regime to the other through the galactic scale can explain the observed rotation curves of galaxies and hence the effects normally attributed to the presence of dark matter. Phenomena on an extragalactic scale such as galactic clusters and the expansion of the universe are controlled by the enhanced gravitational coupling. This provides an explanation of the missing matter normally invoked to account for the observed value of Hubble's constant in relation to observed matter.
Solar system tests of Ho?ava-Lifshitz gravity
Tiberiu Harko; Zoltan Kovács; Francisco S. N. Lobo
2010-10-28T23:59:59.000Z
Recently, a renormalizable gravity theory with higher spatial derivatives in four dimensions was proposed by Ho\\v{r}ava. The theory reduces to Einstein gravity with a non-vanishing cosmological constant in IR, but it has improved UV behaviors. The spherically symmetric black hole solutions for an arbitrary cosmological constant, which represent the generalization of the standard Schwarzschild-(A)dS solution, has also been obtained for the Ho\\v{r}ava-Lifshitz theory. The exact asymptotically flat Schwarzschild type solution of the gravitational field equations in Ho\\v{r}ava gravity contains a quadratic increasing term, as well as the square root of a fourth order polynomial in the radial coordinate, and it depends on one arbitrary integration constant. The IR modified Ho\\v{r}ava gravity seems to be consistent with the current observational data, but in order to test its viability more observational constraints are necessary. In the present paper we consider the possibility of observationally testing Ho\\v{r}ava gravity at the scale of the Solar System, by considering the classical tests of general relativity (perihelion precession of the planet Mercury, deflection of light by the Sun and the radar echo delay) for the spherically symmetric black hole solution of Ho\\v{r}ava-Lifshitz gravity. All these gravitational effects can be fully explained in the framework of the vacuum solution of the gravity. Moreover, the study of the classical general relativistic tests also constrain the free parameter of the solution.
On the condensed matter scheme for emergent gravity and interferometry
G. Jannes
2008-11-10T23:59:59.000Z
An increasingly popular approach to quantum gravity rests on the idea that gravity (and maybe electromagnetism and the other gauge fields) might be an 'emergent phenomenon', in the sense of representing a collective behaviour resulting from a very different microscopic physics. A prominent example of this approach is the condensed matter scheme for quantum gravity, which considers the possibility that gravity emerges as an effective low-energy phenomenon from the quantum vacuum in a way similar to the emergence of collective excitations in condensed matter systems. This condensed matter view of the quantum vacuum clearly hints that, while the term 'ether' has been discredited for about a century, quantum gravity holds many (if not all) of the characteristics that have led people in the past to label various hypothetical substances with the term 'ether'. Since the last burst of enthusiasm for an ether, at the end of the 19th century, was brought to the grave in part by the performance of a series of important experiments in interferometry, the suggestion then naturally arises that maybe interferometry could also play a role in the current discussion on quantum gravity. We will highlight some aspects of this suggestion in the context of the condensed matter scheme for emergent gravity.
Gravity inversion using a binary formulation Richard A. Krahenbuhl* and Yaoguo Li
Gravity inversion using a binary formulation Richard A. Krahenbuhl* and Yaoguo Li Gravity contrast that gives rise to zero gravity response on the surface. As a result, part of the salt structure structure using gravity data can be divided into two general categories. The first are interface inversions
GRAVITY PERTURBED CRAPPER WAVES BENJAMIN F. AKERS, DAVID M. AMBROSE & J. DOUGLAS WRIGHT
Wright, J. Douglas
GRAVITY PERTURBED CRAPPER WAVES BENJAMIN F. AKERS, DAVID M. AMBROSE & J. DOUGLAS WRIGHT Abstract for but gravity is neglected. For certain parameter values, Crapper waves are known to have multi-valued height by the effect of gravity, yielding the existence of gravity-capillary waves nearby to the Crapper waves
Gravity observations and 3D structure of the Earth , F. Chambat
1 Gravity observations and 3D structure of the Earth Y. Ricard1 , F. Chambat Laboratoire des, Michigan-Ann Harbor University, USA. Short title: GRAVITY OBSERVATIONS AND 3D STRUCTURE OF THE EARTH 1. The determination of Earth's gravity field has benefited from various gravity missions that have been launched
Simulations of Solar System observations in alternative theories of gravity
A. Hees; B. Lamine; S. Reynaud; M. -T. Jaekel; C. Le Poncin-Lafitte; V. Lainey; A. Füzfa; J. -M. Courty; V. Dehant; P. Wolf
2013-02-27T23:59:59.000Z
In this communication, we focus on the possibility to test General Relativity (GR) with radioscience experiments. We present simulations of observables performed in alternative theories of gravity using a software that simulates Range/Doppler signals directly from the space time metric. This software allows one to get the order of magnitude and the signature of the modifications induced by an alternative theory of gravity on radioscience signals. As examples, we present some simulations for the Cassini mission in Post-Einsteinian gravity (PEG) and with Standard Model Extension (SME).
On the black hole singularity issue in loop quantum gravity
A. DeBenedictis
2009-07-05T23:59:59.000Z
This paper presents a brief overview on the issue of singularity resolution in loop quantum gravity presented at the Theory Canada IV conference at the Centre de Recherches Math\\'{e}matiques at the Universit\\'{e} de Montr\\'{e}al (June 4-7, 2008). The intended audience is theoretical physicists who are non-specialist in the field and therefore much of the technical detail is omitted here. Instead, a brief review of loop quantum gravity is presented, followed by a survey of previous and current work on results concerning the resolution of the classical black hole singularity within loop quantum gravity.
Flat space (higher spin) gravity with chemical potentials
Michael Gary; Daniel Grumiller; Max Riegler; Jan Rosseel
2014-11-24T23:59:59.000Z
We introduce flat space spin-3 gravity in the presence of chemical potentials and discuss some applications to flat space cosmology solutions, their entropy, free energy and flat space orbifold singularity resolution. Our results include flat space Einstein gravity with chemical potentials as special case. We discover novel types of phase transitions between flat space cosmologies with spin-3 hair and show that the branch that continuously connects to spin-2 gravity becomes thermodynamically unstable for sufficiently large temperature or spin-3 chemical potential.
Particles on a Circle in Canonical Lineal Gravity
R. B. Mann
2001-05-02T23:59:59.000Z
A description of the canonical formulation of lineal gravity minimally coupled to N point particles in a circular topology is given. The Hamiltonian is found to be equal to the time-rate of change of the extrinsic curvature multiplied by the proper circumference of the circle. Exact solutions for pure gravity and for gravity coupled to a single particle are obtained. The presence of a single particle significantly modifies the spacetime evolution by either slowing down or reversing the cosmological expansion of the circle, depending upon the choice of parameters.
Three-dimensional geologic structures from inversion of gravity anomalies
Hinson, Charles Alvin
2012-06-07T23:59:59.000Z
from an analysis of the sampling interval. 39 100 80 z0= 7km p = 1gm/cra R, /R6= 2 ~ 10 60 mgal . ~ ~ Numerical Integration Parker Method 40 20 64 56 48 40 32 km 10 a) 24 16 8 mgal ! km 10b) 16 8 Figure 10. Gravity profile across.... The input was the gravity profile shown in Figure 5. The model parameters are the same used by Oldenburg (1974, Figure 2, p. 533) for the case Z =6km. . . . . . . . . . . . . . . . 33 Comparison of gravity profiles from the cosine model and from...
The periodic standing-wave approximation: post-Minkowski computation
Christopher Beetle; Benjamin Bromley; Napoleón Hernández; Richard H. Price
2007-08-08T23:59:59.000Z
The periodic standing wave method studies circular orbits of compact objects coupled to helically symmetric standing wave gravitational fields. From this solution an approximation is extracted for the strong field, slowly inspiralling motion of black holes and binary stars. Previous work on this model has dealt with nonlinear scalar models, and with linearized general relativity. Here we present the results of the method for the post-Minkowski (PM) approximation to general relativity, the first step beyond linearized gravity. We compute the PM approximation in two ways: first, via the standard approach of computing linearized gravitational fields and constructing from them quadratic driving sources for second-order fields, and second, by solving the second-order equations as an ``exact'' nonlinear system. The results of these computations have two distinct applications: (i) The computational infrastructure for the ``exact'' PM solution will be directly applicable to full general relativity. (ii) The results will allow us to begin supplying initial data to collaborators running general relativistic evolution codes.
Mixed convection and heat management in the Mars gravity biosatellite
Marsh, Jesse B. (Jesse Benjamin)
2007-01-01T23:59:59.000Z
The Mars Gravity Biosatellite will house fifteen mice in a low Earth orbit satellite spinning about its longitudinal axis. The satellite's payload thermal control system will reject heat through the base of the payload ...
Status of Matter-Gravity Couplings in the SME
Tasson, Jay D
2013-01-01T23:59:59.000Z
Constraints on Lorentz violation in matter-gravity couplings are summarized along with existing proposals to obtain sensitivities that exceed current limits by up to 11 orders of magnitude.
Status of Matter-Gravity Couplings in the SME
Jay D. Tasson
2013-08-06T23:59:59.000Z
Constraints on Lorentz violation in matter-gravity couplings are summarized along with existing proposals to obtain sensitivities that exceed current limits by up to 11 orders of magnitude.
Hyperbolic Equations for Vacuum Gravity Using Special Orthonormal Frames
Frank B. Estabrook; R. Steve Robinson; Hugo D. Wahlquist
2004-09-29T23:59:59.000Z
By adopting Nester's higher dimensional special orthonormal frames (HSOF) the tetrad equations for vacuum gravity are put into first order symmetric hyperbolic (FOSH) form with constant coefficients, independent of any time slicing or coordinate specialization.
Gravity wave turbulence revealed by horizontal vibrations of the container
Bruno Issenmann; Eric Falcon
2012-12-20T23:59:59.000Z
We experimentally study the role of the forcing on gravity-capillary wave turbulence. Previous laboratory experiments using spatially localized forcing (vibrating blades) have shown that the frequency power-law exponent of the gravity wave spectrum depends on the forcing parameters. By horizontally vibrating the whole container, we observe a spectrum exponent that does not depend on the forcing parameters for both gravity and capillary regimes. This spatially extended forcing leads to a gravity spectrum exponent in better agreement with the theory than by using a spatially localized forcing. The role of the vessel shape has been also studied. Finally, the wave spectrum is found to scale linearly with the injected power for both regimes whatever the forcing type used.
Vacua and instantons of ghost-free massive gravity
Minjoon Park; Lorenzo Sorbo
2012-12-12T23:59:59.000Z
Recently discovered models of ghost-free massive gravity and bigravity are characterized by a non-trivial potential that gives rise to a rich vacuum structure. We review maximally symmetric vacua of the de Rham-Gabadadze-Tolley (dRGT) massive gravity and of the Hassan-Rosen (HR) bigravity, and discuss their perturbative stability. In particular, we discuss perturbations about self-accelerating vacua in HR bigravity, and argue that, analogously to what was found in the case of dRGT gravity, some of them contain strongly coupled modes. We then show that it is impossible to construct regular instantons connecting different classically stable vacua of dRGT gravity without violating energy conservation or the null energy condition.
New Gravity Wave Treatments for GISS Climate Models
Geller, Marvin A.
Previous versions of GISS climate models have either used formulations of Rayleigh drag to represent unresolved gravity wave interactions with the model-resolved flow or have included a rather complicated treatment of ...
Regional Gravity Survey of the Northern Great Salt Lake Desert...
navigation, search OpenEI Reference LibraryAdd to library Journal Article: Regional Gravity Survey of the Northern Great Salt Lake Desert and Adjacent Areas in Utah, Nevada, and...
Application Of Gravity And Deep Dipole Geoelectrics In The Volcanic...
Gravity And Deep Dipole Geoelectrics In The Volcanic Area Of Mt Etna (Sicily) Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Application Of...
Geodesic multiplication as a tool for classical and quantum gravity
Piret Kuusk; Eugen Paal
2008-03-08T23:59:59.000Z
Algebraic systems called the local geodesic loops and their tangent Akivis algebras are considered. Their possible role in theory of gravity is considered. Quantum conditions for the infinitesimal quantum events are proposed.
Quantized gauge-affine gravity in the superfiber bundle approach
Meziane, A.; Tahiri, M. [Laboratoire de Physique Theorique, Universite d'Oran Es-senia, 31100 Oran (Algeria)
2005-05-15T23:59:59.000Z
The quantization of gauge-affine gravity within the superfiber bundle formalism is proposed. By introducing an even pseudotensorial 1-superform over a principal superfiber bundle with superconnection, we obtain the geometrical Becchi-Rouet-Stora-Tyutin (BRST) and anti-BRST transformations of the fields occurring in such a theory. Reducing the four-dimensional general affine group double-covering GA(4,R) to the Poincare group double-covering ISO(1,3) we also find the BRST and anti-BRST transformations of the fields present in Einstein's gravity. Furthermore, we give a prescription leading to the construction of both BRST-invariant gauge-fixing action for gauge-affine gravity and Einstein's gravity.
Errata to "Flat Spacetime Vacuum in Loop Quantum Gravity"
A. Mikovic
2006-06-19T23:59:59.000Z
We give the correct expressions for the spin network evaluations proposed in Class. Quant. Grav. 21 (2004) 3909 as the coefficients of the quantum gravity vacuum wavefunction in the spin network basis.
Constraining gravity using entanglement in AdS/CFT
Shamik Banerjee; Arpan Bhattacharyya; Apratim Kaviraj; Kallol Sen; Aninda Sinha
2014-07-09T23:59:59.000Z
We investigate constraints imposed by entanglement on gravity in the context of holography. First, by demanding that relative entropy is positive and using the Ryu-Takayanagi entropy functional, we find certain constraints at a nonlinear level for the dual gravity. Second, by considering Gauss-Bonnet gravity, we show that for a class of small perturbations around the vacuum state, the positivity of the two point function of the field theory stress tensor guarantees the positivity of the relative entropy. Further, if we impose that the entangling surface closes off smoothly in the bulk interior, we find restrictions on the coupling constant in Gauss-Bonnet gravity. We also give an example of an anisotropic excited state in an unstable phase with broken conformal invariance which leads to a negative relative entropy.
Gravity and its Mysteries: Some Thoughts and Speculations
A. Zee
2008-05-14T23:59:59.000Z
I gave a rambling talk about gravity and its many mysteries at Chen-Ning Yang's 85th Birthday Celebration held in November 2007. I don't have any answers.
The evolution of miscible gravity currents in horizontal porous layers
Szulczewski, Michael Lawrence
Gravity currents of miscible fluids in porous media are important to understand because they occur in important engineering projects, such as enhanced oil recovery and geologic CO[subscript 2] sequestration. These flows ...
An alternative derivation of the Minimal massive 3D gravity
Ahmet Baykal
2014-08-22T23:59:59.000Z
By using the algebra of exterior forms and the first order formalism with constraints, an alternative derivation of the field equations for the Minimal massive 3D gravity model is presented.
Ground Gravity Survey At Dixie Valley Geothermal Area (Iovenitti...
project area. These data were used in conjunction with past gravity data reported in by Smith et al (2001) and Blackwell et al (2005). The analysis of these data had not been...
Dust-shell Universe in the modified gravity scenario
Michael Maziashvili
2005-04-15T23:59:59.000Z
The dynamics of the dust-shell model of universe is exactly solved for the modified Schwarzschild solution. This solution is used to derive the cosmology corresponding to the modified gravity.
Absence of scalar hair in scalar-tensor gravity
Valerio Faraoni; Thomas P. Sotiriou
2013-03-04T23:59:59.000Z
Stationary, asymptotically flat black holes in scalar-tensor theories of gravity are studied. It is shown that such black holes have no scalar hair and are the same as in General Relativity.
Gravity-free hydraulic jumps and metal femtocups
Rama Govindarajan; Manikandan Mathur; Ratul DasGupta; N. R. Selvi; Neena Susan John; G. U. Kulkarni
2006-10-03T23:59:59.000Z
Hydraulic jumps created by gravity are seen every day in the kitchen sink. We show that at small scales a circular hydraulic jump can be created in the absence of gravity, by surface tension. The theory is motivated by our experimental finding of a height discontinuity in spreading submicron molten metal droplets created by pulsed-laser ablation. By careful control of initial conditions, we show that this leads to solid femtolitre cups of gold, silver, copper, niobium and tin.
Gravity Effects on Antimatter in the Standard-Model Extension
Jay D. Tasson
2015-01-30T23:59:59.000Z
The gravitational Standard-Model Extension (SME) is the general field-theory based framework for the analysis of CPT and Lorentz violation. In this work we summarize the implications of Lorentz and CPT violation for antimatter gravity in the context of the SME. Implications of various attempts to place indirect limits on anomalous antimatter gravity are considered in the context of SME-based models.
Gravity Effects on Antimatter in the Standard-Model Extension
Tasson, Jay D
2015-01-01T23:59:59.000Z
The gravitational Standard-Model Extension (SME) is the general field-theory based framework for the analysis of CPT and Lorentz violation. In this work we summarize the implications of Lorentz and CPT violation for antimatter gravity in the context of the SME. Implications of various attempts to place indirect limits on anomalous antimatter gravity are considered in the context of SME-based models.
NUT-Charged Black Holes in Gauss-Bonnet Gravity
M. H. Dehghani; R. B. Mann
2005-11-30T23:59:59.000Z
We investigate the existence of Taub-NUT/bolt solutions in Gauss-Bonnet gravity and obtain the general form of these solutions in $d$ dimensions. We find that for all non-extremal NUT solutions of Einstein gravity having no curvature singularity at $r=N$, there exist NUT solutions in Gauss-Bonnet gravity that contain these solutions in the limit that the Gauss-Bonnet parameter $\\alpha$ goes to zero. Furthermore there are no NUT solutions in Gauss-Bonnet gravity that yield non-extremal NUT solutions to Einstein gravity having a curvature singularity at $r=N$ in the limit $% \\alpha \\to 0$. Indeed, we have non-extreme NUT solutions in $2+2k$ dimensions with non-trivial fibration only when the $2k$-dimensional base space is chosen to be $\\mathbb{CP}^{2k}$. We also find that the Gauss-Bonnet gravity has extremal NUT solutions whenever the base space is a product of 2-torii with at most a 2-dimensional factor space of positive curvature. Indeed, when the base space has at most one positively curved two dimensional space as one of its factor spaces, then Gauss-Bonnet gravity admits extreme NUT solutions, even though there a curvature singularity exists at $r=N$. We also find that one can have bolt solutions in Gauss-Bonnet gravity with any base space with factor spaces of zero or positive constant curvature. The only case for which one does not have bolt solutions is in the absence of a cosmological term with zero curvature base space.
Stochastic Quantization of the Ho?ava Gravity
Fu-Wen Shu; Yong-Shi Wu
2009-06-09T23:59:59.000Z
The stochastic quantization method is applied to the recent proposal by Ho\\v{r}ava for gravity. We show that in contrast to General Relativity, the Ho\\v{r}ava's action, satisfying the detailed balance condition, has a stable, non-perturbative quantum vacuum when the DeWitt parameter $\\lambda$ is not greater than 1/3, providing a possible candidate for consistent quantum gravity.
A bird's eye view of f(R)-gravity
S. Capozziello; M. De Laurentis; V. Faraoni
2009-10-02T23:59:59.000Z
We survey the landscape of $f(R)$ theories of gravity in their various formulations, which have been used to model the cosmic acceleration as alternatives to dark energy and dark matter. Besides, we take into account the problem of gravitational waves in such theories. We discuss some successes of $f(R)$-gravity (where $f(R)$ is a generic function of Ricci scalar $R$), theoretical and experimental challenges that they face in order to satisfy minimal criteria for viability.
Entropy and Area of Black Holes in Loop Quantum Gravity
I. B. Khriplovich
2002-03-31T23:59:59.000Z
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.
Finite field-dependent symmetries in perturbative quantum gravity
Upadhyay, Sudhaker, E-mail: sudhaker@boson.bose.res.in
2014-01-15T23:59:59.000Z
In this paper we discuss the absolutely anticommuting nilpotent symmetries for perturbative quantum gravity in general curved spacetime in linear and non-linear gauges. Further, we analyze the finite field-dependent BRST (FFBRST) transformation for perturbative quantum gravity in general curved spacetime. The FFBRST transformation changes the gauge-fixing and ghost parts of the perturbative quantum gravity within functional integration. However, the operation of such symmetry transformation on the generating functional of perturbative quantum gravity does not affect the theory on physical ground. The FFBRST transformation with appropriate choices of finite BRST parameter connects non-linear Curci–Ferrari and Landau gauges of perturbative quantum gravity. The validity of the results is also established at quantum level using Batalin–Vilkovisky (BV) formulation. -- Highlights: •The perturbative quantum gravity is treated as gauge theory. •BRST and anti-BRST transformations are developed in linear and non-linear gauges. •BRST transformation is generalized by making it finite and field dependent. •Connection between linear and non-linear gauges is established. •Using BV formulation the results are established at quantum level also.
Minimal Liouville Gravity correlation numbers from Douglas string equation
Alexander Belavin; Boris Dubrovin; Baur Mukhametzhanov
2014-09-11T23:59:59.000Z
We continue the study of $(q,p)$ Minimal Liouville Gravity with the help of Douglas string equation. We generalize the results of \\cite{Moore:1991ir}, \\cite{Belavin:2008kv}, where Lee-Yang series $(2,2s+1)$ was studied, to $(3,3s+p_0)$ Minimal Liouville Gravity, where $p_0=1,2$. We demonstrate that there exist such coordinates $\\tau_{m,n}$ on the space of the perturbed Minimal Liouville Gravity theories, in which the partition function of the theory is determined by the Douglas string equation. The coordinates $\\tau_{m,n}$ are related in a non-linear fashion to the natural coupling constants $\\lambda_{m,n}$ of the perturbations of Minimal Lioville Gravity by the physical operators $O_{m,n}$. We find this relation from the requirement that the correlation numbers in Minimal Liouville Gravity must satisfy the conformal and fusion selection rules. After fixing this relation we compute three- and four-point correlation numbers when they are not zero. The results are in agreement with the direct calculations in Minimal Liouville Gravity available in the literature \\cite{Goulian:1990qr}, \\cite{Zamolodchikov:2005sj}, \\cite{Belavin:2006ex}.
Loop Quantum Gravity Phenomenology: Linking Loops to Observational Physics
Florian Girelli; Franz Hinterleitner; Seth A. Major
2012-12-13T23:59:59.000Z
Research during the last decade demonstrates that effects originating on the Planck scale are currently being tested in multiple observational contexts. In this review we discuss quantum gravity phenomenological models and their possible links to loop quantum gravity. Particle frameworks, including kinematic models, broken and deformed Poincar\\'e symmetry, non-commutative geometry, relative locality and generalized uncertainty principle, and field theory frameworks, including Lorentz violating operators in effective field theory and non-commutative field theory, are discussed. The arguments relating loop quantum gravity to models with modified dispersion relations are reviewed, as well as, arguments supporting the preservation of local Lorentz invariance. The phenomenology related to loop quantum cosmology is briefly reviewed, with a focus on possible effects that might be tested in the near future. As the discussion makes clear, there remains much interesting work to do in establishing the connection between the fundamental theory of loop quantum gravity and these specific phenomenological models, in determining observational consequences of the characteristic aspects of loop quantum gravity, and in further refining current observations. Open problems related to these developments are highlighted. characteristic aspects of loop quantum gravity, and in further refining current observations. Open problems related to these developments are highlighted.
Testing Horava-Lifshitz gravity using thin accretion disk properties
Harko, Tiberiu; Kovacs, Zoltan; Lobo, Francisco S. N. [Department of Physics and Center for Theoretical and Computational Physics, University of Hong Kong, Pok Fu Lam Road (Hong Kong); Centro de Fisica Teorica e Computacional, Faculdade de Ciencias da Universidade de Lisboa, Avenida Professor Gama Pinto 2, P-1649-003 Lisboa (Portugal)
2009-08-15T23:59:59.000Z
Recently, a renormalizable gravity theory with higher spatial derivatives in four dimensions was proposed by Horava. The theory reduces to Einstein gravity with a nonvanishing cosmological constant in IR, but it has improved UV behaviors. The spherically symmetric black hole solutions for an arbitrary cosmological constant, which represent the generalization of the standard Schwarzschild-(anti) de Sitter solution, have also been obtained for the Horava-Lifshitz theory. The exact asymptotically flat Schwarzschild-type solution of the gravitational field equations in Horava gravity contains a quadratic increasing term, as well as the square root of a fourth order polynomial in the radial coordinate, and it depends on one arbitrary integration constant. The IR-modified Horava gravity seems to be consistent with the current observational data, but in order to test its viability more observational constraints are necessary. In the present paper we consider the possibility of observationally testing Horava gravity by using the accretion disk properties around black holes. The energy flux, the temperature distribution, the emission spectrum, as well as the energy conversion efficiency are obtained, and compared to the standard general relativistic case. Particular signatures can appear in the electromagnetic spectrum, thus leading to the possibility of directly testing Horava gravity models by using astrophysical observations of the emission spectra from accretion disks.
Seismic isolation of two dimensional periodic foundations
Yan, Y.; Mo, Y. L., E-mail: yilungmo@central.uh.edu [University of Houston, Houston, Texas 77004 (United States); Laskar, A. [Indian Institute of Technology Bombay, Powai, Mumbai (India); Cheng, Z.; Shi, Z. [Beijing Jiaotong University, Beijing (China); Menq, F. [University of Texas, Austin, Texas 78712 (United States); Tang, Y. [Argonne National Laboratory, Argonne, Illinois 60439 (United States)
2014-07-28T23:59:59.000Z
Phononic crystal is now used to control acoustic waves. When the crystal goes to a larger scale, it is called periodic structure. The band gaps of the periodic structure can be reduced to range from 0.5?Hz to 50?Hz. Therefore, the periodic structure has potential applications in seismic wave reflection. In civil engineering, the periodic structure can be served as the foundation of upper structure. This type of foundation consisting of periodic structure is called periodic foundation. When the frequency of seismic waves falls into the band gaps of the periodic foundation, the seismic wave can be blocked. Field experiments of a scaled two dimensional (2D) periodic foundation with an upper structure were conducted to verify the band gap effects. Test results showed the 2D periodic foundation can effectively reduce the response of the upper structure for excitations with frequencies within the frequency band gaps. When the experimental and the finite element analysis results are compared, they agree well with each other, indicating that 2D periodic foundation is a feasible way of reducing seismic vibrations.
Anti-gravity and/or dark matter contributions from massive gravity
Bebronne, Michael V
2009-01-01T23:59:59.000Z
Recently, the static spherically symmetric solution of the gravitational field equations have been found in theories describing massive graviton with spontaneous breaking of the Lorentz invariance. These solutions, which show off two integration constants instead of one in General Relativity, are discussed. They are candidates for modified black holes provided they are stable against small perturbations. These solutions may have both attractive or repulsive behavior at large distances. Therefore, these modified black holes may mimics the presence of dark matter or be a source of anti-gravity.
Characterising Vainshtein Solutions in Massive Gravity
Fulvio Sbisa'; Gustavo Niz; Kazuya Koyama; Gianmassimo Tasinato
2014-06-17T23:59:59.000Z
We study static, spherically symmetric solutions in a recently proposed ghost-free model of non-linear massive gravity. We focus on a branch of solutions where the helicity-0 mode can be strongly coupled within certain radial regions, giving rise to the Vainshtein effect. We truncate the analysis to scales below the gravitational Compton wavelength, and consider the weak field limit for the gravitational potentials, while keeping all non-linearities of the helicity-0 mode. We determine analytically the number and properties of local solutions which exist asymptotically on large scales, and of local (inner) solutions which exist on small scales. We find two kinds of asymptotic solutions, one of which is asymptotically flat, while the other one is not, and also two types of inner solutions, one of which displays the Vainshtein mechanism, while the other exhibits a self-shielding behaviour of the gravitational field. We analyse in detail in which cases the solutions match in an intermediate region. The asymptotically flat solutions connect only to inner configurations displaying the Vainshtein mechanism, while the non asymptotically flat solutions can connect with both kinds of inner solutions. We show furthermore that there are some regions in the parameter space where global solutions do not exist, and characterise precisely in which regions of the phase space the Vainshtein mechanism takes place.
Symmetry and Evolution in Quantum Gravity
Sean Gryb; Karim Thebault
2014-03-25T23:59:59.000Z
We propose an operator constraint equation for the wavefunction of the Universe that admits genuine evolution. While the corresponding classical theory is equivalent to the canonical decomposition of General Relativity, the quantum theory makes predictions that are distinct from Wheeler-DeWitt cosmology. Furthermore, the local symmetry principle - and corresponding observables - of the theory have a direct interpretation in terms of a conventional gauge theory, where the gauge symmetry group is that of spatial conformal diffeomorphisms (that preserve the spatial volume of the Universe). The global evolution is in terms of an arbitrary parameter that serves only as an unobservable label for successive states of the Universe. Our proposal follows unambiguously from a suggestion of York whereby the independently specifiable initial data in the action principle of General Relativity is given by a conformal geometry and the spatial average of the York time on the spacelike hypersurfaces that bound the variation. Remarkably, such a variational principle uniquely selects the form of the constraints of the theory so that we can establish a precise notion of both symmetry and evolution in quantum gravity.
Infrared modified gravity with dynamical torsion
Nikiforova, V. [Physics Department, Moscow State University, Moscow, 119899 (Russian Federation); Institute for Nuclear Research of the Russian Academy of Sciences, 60th October Anniversary Prospect, 7a, Moscow, 117312 (Russian Federation); Randjbar-Daemi, S. [Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, I-34014, Trieste (Italy); Rubakov, V. [Institute for Nuclear Research of the Russian Academy of Sciences, 60th October Anniversary Prospect, 7a, Moscow, 117312 (Russian Federation)
2009-12-15T23:59:59.000Z
We continue the recent study of the possibility of constructing a consistent infrared modification of gravity by treating the vierbein and connection as independent dynamical fields. We present the generalized Fierz-Pauli equation that governs the propagation of a massive spin-2 mode in a model of this sort in the backgrounds of arbitrary torsionless Einstein manifolds. We show explicitly that the number of propagating degrees of freedom in these backgrounds remains the same as in flat space-time. This generalizes the recent result that the Boulware-Deser phenomenon does not occur in de Sitter and anti-de Sitter backgrounds. We find that, at least for weakly curved backgrounds, there are no ghosts in the model. We also discuss the interaction of sources in flat background. It is generally believed that the spinning matter is the only source of torsion. Our flat space study shows that this is not the case. We demonstrate that an ordinary conserved symmetric energy-momentum tensor can also generate torsion fields and thus excite massive spin-2 degrees of freedom.
Quantization of neutron in Earth's gravity
Pulak Ranjan Giri
2007-08-22T23:59:59.000Z
Gravity is the weakest of all four known forces in the universe. Quantum states of an elementary particle due to such a weak field is certainly very shallow and would therefore be an experimental challenge to detect. Recently an experimental attempt was made by V. V. Nesvizhevsky et al., Nature 415, 297 (2002), to measure the quantum states of a neutron, which shows that ground state and few excited states are \\sim 10^{-12}eV. We show that the energy of the ground state of a neutron confined above Earth's surface should be \\sim 10^{-37}eV. The experimentally observed energy levels are 10^{25} times deeper than the actual energy levels it should be and thus certainly not due to gravitational effect of Earth. Therefore the correct interpretation for the painstaking experimental results of Ref. \\cite{nes1} is due to the confinement potential of a one dimensional box of length L \\sim 50\\mu m, generated from the experimental setup as commented before \\cite{hansoon}. Our results thus creates a new challenge to the experimentalist to resolve the shallow energy levels of the neutron in Earth's gravitational field in future.
Exploring Cartan gravity with dynamical symmetry breaking
H. F. Westman; T. G. Zlosnik
2014-03-24T23:59:59.000Z
It has been known for some time that General Relativity can be regarded as a Yang-Mills-type gauge theory in a symmetry broken phase. In this picture the gravity sector is described by an $SO(1,4)$ or $SO(2,3)$ gauge field $A^{a}_{\\phantom{a}b\\mu}$ and Higgs field $V^{a}$ which acts to break the symmetry down to that of the Lorentz group $SO(1,3)$. This symmetry breaking mirrors that of electroweak theory. However, a notable difference is that while the Higgs field $\\Phi$ of electroweak theory is taken as a genuine dynamical field satisfying a Klein-Gordon equation, the gauge independent norm $V^2\\equiv \\eta_{ab}V^{a}V^{b}$ of the Higgs-type field $V^a$ is typically regarded as non-dynamical. Instead, in many treatments $V^a$ does not appear explicitly in the formalism or is required to satisfy $V^2 = \\mathrm{const.} \
Roche Lobe Shapes for testing MOND-like Modified Gravity
HongSheng Zhao; LanLan Tian
2006-02-02T23:59:59.000Z
Dark Matter (DM) theories and mass-tracing-light theories like MOND are by construction nearly degenerate on galactic scales, but not when it comes to the predicted shapes of Roche Lobes of a two-body system (e.g., a globular cluster orbiting a host galaxy). We show that the flattening of the Roche lobe is sensitive to the function mu(g) in modification of the law of gravity. We generalise the analytical results obtained in the deep-MOND limit by Zhao (2005, astro-ph/0511713 and astro-ph/0512425), and consider a binary in the framework of a MOND-like gravity modification function mu(g) or a general non-Keplerian gravity g \\propto R^-\\zeta. We give analytical expressions for the inner Lagrange point and Robe lobe axis ratios. The Roche lobe volume is proven to scale linearly with the true mass ratio, which applies to any mu(g), hence mass-tracing light models would overpredict the Roche lobe of a DM-poor globular cluster in a DM-rich host galaxy, and underpredict the size of a DM-richer dwarf satellite. The lobes are squashed with the flattening ~ 0.4 in the strong gravity and ~ 0.6 in the weak gravity; a precise measurement of the flattening could be used to verify the anisotropic dilation effect which is generic to MOND-like gravity. We generalise these results for extended mass distribution, and compare predicted Roche radii in different gravity theories with limiting radii of observed globular clusters and dwarf galaxy satellites.
Metallurgy Department Progress Report for the Period
Dlcfc^ooWS imsm "-"' Metallurgy Department Progress Report for the Period 1 January to 31 December 1962 (Uw National Laboratory, DK-4000 Roskilde, Denmark July 1963 #12;Risř-R-486 METALLURGY DEPARTMENT PROGRESS REPORT FOR THE PERIOD 1 JANUARY TO 31 DECEMBER 1982 Abstract. The activities of the Metallurgy
Broadband solar absorption enhancement via periodic
Province, 230009, P. R. China. Solution processed colloidal quantum dot (CQD) solar cells have greatBroadband solar absorption enhancement via periodic nanostructuring of electrodes Michael M. Adachi demonstrate a bottom- illuminated periodic nanostructured CQD solar cell that enhances broadband absorption
Unscreening modified gravity in the matter power spectrum
Lucas Lombriser; Fergus Simpson; Alexander Mead
2015-01-20T23:59:59.000Z
Viable modifications of gravity that may produce cosmic acceleration need to be screened in high-density regions such as the Solar System, where general relativity is well tested. Screening mechanisms also prevent strong anomalies in the large-scale structure and limit the constraints that can be inferred on these gravity models from cosmology. We find that by suppressing the contribution of the screened high-density regions in the matter power spectrum, allowing a greater contribution of unscreened low densities, modified gravity models can be more readily discriminated from the concordance cosmology. Moreover, by variation of density thresholds, degeneracies with other effects may be dealt with more adequately. Specializing to chameleon gravity as a worked example for screening in modified gravity, employing N-body simulations of f(R) models and the halo model of chameleon theories, we demonstrate the effectiveness of this method. We find that a percent-level measurement of the clipped power at k Solar System tests or distance indicators in unscreened dwarf galaxies.
Unscreening modified gravity in the matter power spectrum
Lombriser, Lucas; Mead, Alexander
2015-01-01T23:59:59.000Z
Viable modifications of gravity that may produce cosmic acceleration need to be screened in high-density regions such as the Solar System, where general relativity is well tested. Screening mechanisms also prevent strong anomalies in the large-scale structure and limit the constraints that can be inferred on these gravity models from cosmology. We find that by suppressing the contribution of the screened high-density regions in the matter power spectrum, allowing a greater contribution of unscreened low densities, modified gravity models can be more readily discriminated from the concordance cosmology. Moreover, by variation of density thresholds, degeneracies with other effects may be dealt with more adequately. Specializing to chameleon gravity as a worked example for screening in modified gravity, employing N-body simulations of f(R) models and the halo model of chameleon theories, we demonstrate the effectiveness of this method. We find that a percent-level measurement of the clipped power at k < 0.3 h...
Waste Isolation Pilot Plant (WIPP) site gravity survey and interpretation
Barrows, L.J.; Fett, J.D.
1983-04-01T23:59:59.000Z
A portion of the WIPP site has been extensively surveyed with high-precision gravity. The main survey (in T22S, R31E) covered a rectangular area 2 by 4-1/3 mi encompassing all of WIPP site Zone II and part of the disturbed zone to the north of the site. Stations were at 293-ft intervals along 13 north-south lines 880 ft apart. The data are considered accurate to within a few hundredths of a milligal. Long-wavelength gravity anomalies correlate well with seismic time structures on horizons below the Castile Formation. Both the gravity anomalies and the seismic time structures are interpreted as resulting from related density and velocity variations within the Ochoan Series. Shorter wavelength negative gravity anomalies are interpreted as resulting from bulk density alteration in the vicinity of karst conduits. The WIPP gravity survey was unable to resolve low-amplitude, long-wavelength anomalies that should result from the geologic structures within the disturbed zone. It did indicate the degree and character of karst development within the surveyed area.
Variable-Period Undulators For Synchrotron Radiation
Shenoy, Gopal (Naperville, IL); Lewellen, John (Plainfield, IL); Shu, Deming (Darien, IL); Vinokurov, Nikolai (Novosibirsk, RU)
2005-02-22T23:59:59.000Z
A new and improved undulator design is provided that enables a variable period length for the production of synchrotron radiation from both medium-energy and high-energy storage rings. The variable period length is achieved using a staggered array of pole pieces made up of high permeability material, permanent magnet material, or an electromagnetic structure. The pole pieces are separated by a variable width space. The sum of the variable width space and the pole width would therefore define the period of the undulator. Features and advantages of the invention include broad photon energy tunability, constant power operation and constant brilliance operation.