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Today LED Holiday Lights, Tomorrow the World?
Gordon, Kelly L.
2004-12-20
This article for The APEM Advantage, the quarterly newsletter of the Association of Professional Energy Managers (APEM) describes the recent increase in the popularity of light emitting diode (LED) lighting and compares LED light output with that of incandescent and compact fluorescent lighting.
How Do Holiday Lights Work? | Department of Energy
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Save Money with LED Holiday Light Strings | Department of Energy
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 DeliciousMathematicsEnergyInterestedReplacement-2-AA-1 SECTION JSTEM-ing theSummarySavannah River SiteEnergySave
Light superconducting strings in the Galaxy
Francesc Ferrer; Tanmay Vachaspati
2006-08-08
Observations of the Milky Way by the SPI/INTEGRAL satellite have confirmed the presence of a strong 511 KeV gamma-ray line emission from the bulge, which require an intense source of positrons in the galactic center. These observations are hard to account for by conventional astrophysical scenarios, whereas other proposals, such as light DM, face stringent constraints from the diffuse gamma-ray background. Here we suggest that light superconducting strings could be the source of the observed 511 KeV emission. The associated particle physics, at the ~ 1 TeV scale, is within reach of planned accelerator experiments, while the distinguishing spatial distribution, proportional to the galactic magnetic field, could be mapped by SPI or by future, more sensitive, satellite missions.
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Threading plasmonic nanoparticle strings with light
Herrmann, Lars O.; Valev, Ventsislav K.; Tserkezis, Christos; Barnard, Jonathan S.; Kasera, Setu; Scherman, Oren A.; Aizpurua, Javier; Baumberg, Jeremy J.
2014-07-28
with the 805 nm laser. (c,d) Simulated spectra for 50 and 60 nm NPs formed into threads, for resonant chain lengths of six and four NPs, respectively. The grey shading depicts the FWHM of the experimentally observed resonance. The simulations show... the thread, excellent prospects exist for device application in photovoltaics, sensing and surface-enhanced Raman scattering. By further tailoring the light fields, entirely new structures can be created. For instance, using light with azimuthal angular...
Anomaly of Tensionless String in Light-cone Gauge
Kenta Murase
2015-03-04
The classical tensionless string theory has the spacetime conformal symmetry. We expect and require that the quantum tensionless string theory has it too. In the BRST quantization method, the theory has no spacetime conformal anomaly in two dimensions. On the other hand, in the light-cone gauge quantization without the mode expansion, the theory in $D>3$ has the spacetime conformal anomaly in the traceless part of $[\\mathcal{J}^{-I}, \\mathcal{K}^{J}]$ in some operator order. In this paper, we consider a tensionless closed bosonic string in the light-cone gauge and investigate the spacetime conformal anomaly in the theory with the mode expansion. The appearance of the spacetime conformal anomaly in the light-cone gauge is different between the case of $D>3$ and the case of $D=3$ and depends on the choice of the operator order. Therefore we must consider dangerous commutators in the spacetime conformal symmetry of $D>3$ and $D=3$ in each operator order separately. Specifically we calculate dangerous commutators, $[\\mathcal{J}^{-I},\\mathcal{K}^{K}]$ in $D>3$ and $\\tilde{\\mathcal{K}}^{-}\\equiv -i[\\mathcal{J}^{-}, \\tilde{\\mathcal{K}}^{-}]$ and $[\\mathcal{J}^{-}, \\tilde{\\mathcal{K}}^{-}]$ in $D=3$, in two types of the operator order.
Anomaly of Tensionless String in Light-cone Gauge
Murase, Kenta
2015-01-01
The classical tensionless string theory has the spacetime conformal symmetry. We expect and require that the quantum tensionless string theory has it too. In the BRST quantization method, the theory has no spacetime conformal anomaly in two dimensions. On the other hand, in the light-cone gauge quantization without the mode expansion, the theory in $D>3$ has the spacetime conformal anomaly in the traceless part of $[\\mathcal{J}^{-I}, \\mathcal{K}^{J}]$ in some operator order. In this paper, we consider a tensionless closed bosonic string in the light-cone gauge and investigate the spacetime conformal anomaly in the theory with the mode expansion. The appearance of the spacetime conformal anomaly in the light-cone gauge is different between the case of $D>3$ and the case of $D=3$ and depends on the choice of the operator order. Therefore we must consider dangerous commutators in the spacetime conformal symmetry of $D>3$ and $D=3$ in each operator order separately. Specifically we calculate dangerous commutators...
South Carolina Community Lights Up the Season with Energy-Efficient...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
South Carolina Community Lights Up the Season with Energy-Efficient Holiday Lights South Carolina Community Lights Up the Season with Energy-Efficient Holiday Lights December 20,...
Soebarto, V. I.; Haberl, J. S.; Degelman, L. O.
1997-01-01
lights been left on, the building would have consumed 100 kW more electricity every hour. The total electricity savings was about 31,200 kWh over 13 days, which is equivalent to a total cost saving of $936.00. If the College continues to turn off...
Proton Stability, Gauge Coupling Unification and a Light $Z^\\prime$ in Heterotic-string Models
Alon E. Faraggi; Viraf M. Mehta
2013-06-11
We explore the phenomenological viability of a light Z' in heterotic-string models, whose existence has been motivated by proton stability arguments. A class of quasi-realistic string models that produce such a viable Z' are the Left-Right Symmetric (LRS) heterotic-string models in the free fermionic formulation. A key feature of these models is that the matter charges under U(1)_Z' do not admit an E6 embedding. The light Z' in the LRS heterotic-string models forbids baryon number violating operators, while allowing lepton number violating operators, hence suppressing proton decay yet allowing for sufficiently small neutrino masses via a seesaw mechanism. We show that the constraints imposed by the gauge coupling data and heterotic-string coupling unification nullify the viability of a light Z' in these models. We further argue that agreement with the gauge coupling data necessitates that the U(1)_Z' charges admit an E6 embedding. We discuss how viable string models with this property may be constructed.
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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 Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation CurrentHenry Bellamy, Ph.D.Food Drive Holiday Food Drive Laboratory employees
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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 Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation CurrentHenry Bellamy, Ph.D.Food Drive Holiday Food Drive Laboratory
Observational constraints on light cosmic strings from photometry and pulsar timing
M. S. Pshirkov; A. V. Tuntsov
2009-11-25
We constrain the cosmological density of cosmic string loops using two observational signatures -- gravitational microlensing and the Kaiser-Stebbins effect. Photometry from RXTE and CoRoT space missions and pulsar timing from Parkes Pulsar Timing Array, Arecibo and Green Bank radio telescopes allow us to probe cosmic strings in a wide range of tensions $G\\mu/c^2=10^{-16}\\div10^{-10}$. We find that pulsar timing data provide the most stringent constraints on the abundance of light strings at the level $\\Omega_s \\sim 10^{-3}$. Future observational facilities such as the Square Kilometer Array will allow one to improve these constraints by orders of magnitude.
Broader source: Energy.gov [DOE]
The 6th Annual GovCon Holiday Soiree will be held at the Kennedy Center on Monday, December 8, from 5:30pm to 7:30pm. The event is expected to bring together more than 200 representatives of women-...
Keep Foodborne Illness from Spoiling Holiday Parties (Spanish)
Nutrition, Food and
2008-12-17
Food safety is especially important during the holidays. Learn how to protect your family and friends from food-borne illness. A recipe for Holiday Eggnog is included....
National Nuclear Security Administration (NNSA)
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EECBG Success Story: North Pole's Holiday Wish for an Energy...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Pole's Holiday Wish for an Energy Efficient 2012 EECBG Success Story: North Pole's Holiday Wish for an Energy Efficient 2012 December 23, 2011 - 4:20pm Addthis The city of North...
A Probabilistic Approach of Designing Driving Circuits for Strings of High-Brightness Light
Lehman, Brad
Email : abhattac@ece.neu.edu Abstract-Often, High Brightness LEDs (HB-LED) are connected in series to create strings. According to their data sheets, the HB-LEDs have a variation in their forward voltage in parallel. This paper proposes a probabilistic approach for modeling the forward voltage drop across the HB-LEDs
Proton Stability and Light $Z^\\prime$ Inspired by String Derived Models
Alon E. Faraggi; Viraf M. Mehta
2011-06-15
Proton stability is one of the most perplexing puzzles in particle physics. While the renormalizable Standard Model forbids proton decay mediating operators due to accidental global symmetries, many of its extensions introduce such dimension four, five and six operators. Furthermore, it is, in general, expected that quantum gravity only respects local gauge, or discreet, symmetries. String theory provides the arena to study particle physics in a consistent framework of perturbative quantum gravity. An appealing proposition, in this context, is that the dangerous operators are suppressed by an Abelian gauge symmetry, which is broken near the TeV scale. A viable U(1) symmetry should also be anomaly free, be family universal, and allow the generation of fermion masses via the Higgs mechanism. We discuss such U(1) symmetries that arise in quasi--realistic free fermionic heterotic--string derived models. Ensuring that the U(1) symmetry is anomaly free at the low scale requires that the Standard Model spectrum is augmented by additional states that are compatible with the charge assignments in the string models. We construct such string--inspired models and discuss some of their phenomenological implications.
Reduce Waste and Save Energy this Holiday Season
Office of Energy Efficiency and Renewable Energy (EERE)
Reduce waste and save energy this holiday season whether you're shopping, eating, partying, decorating, or wrapping.
Inside this issue: Green Holiday Tips 2
Kidd, William S. F.
Inside this issue: Message 1 Green Holiday Tips 2 Real vs. Fake Tree 3 Semester wrap up: Energy a record number of CFL bulbs being distributed in the living residences, had another great energy campaign such as compost bins, bird feeders, energy/water saving appliances, bikes or bus passes make great gifts! Make
Museum Closed for Christmas Holiday
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Museum Closed for Thanksgiving Holiday
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Leveraging Holidays and Other Events | Department of Energy
Broader source: Energy.gov (indexed) [DOE]
Driving Demand Peer Exchange Call Series: Leveraging Holidays and Other Events, Call Slides and Discussion Summary, November 7, 2013. Call Slides and Discussion Summary More...
Buying an Appliance this Holiday Season? ENERGY STAR Products...
Broader source: Energy.gov (indexed) [DOE]
When shopping for appliances or electronics for the holidays, look for the ENERGY STAR and EnergyGuide labels. | Photo by Dennis Schroeder, NREL 22090. When shopping for...
Your Holidays...Brought to You by Fuel Cells
Broader source: Energy.gov [DOE]
A story about how fuel cells are helping bring the holidays to you is currently posted on the Energy Department's Blog.
Informations et rservations : ce.pv-holidays.com
Arleo, Angelo
Informations et réservations : ce.pv-holidays.com * Offre valable pour tout séjour de 7 nuits détails sur ce.pv-holidays.com. Offre valable sur l'hébergement seul (hors frais de dossier, prestations cumulable avec votre remise partenaire, toute offre promotionnelle ou réductions. PV-CPDistribution, Société
Buying an Appliance this Holiday Season? ENERGY STAR Products...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Efficiency and Renewable Energy How can I participate? Look for the ENERGY STAR label to find energy-efficient appliances. It's the holiday season, which is a perfect time...
LED Holiday Lights: Festive, Safe, and Efficient! | Department of Energy
Office of Energy Efficiency and Renewable Energy (EERE) 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 Center Home Page on Delicious RankADVANCED MANUFACTURING OFFICE INDUSTRIALU.S. DepartmentJeanKeyLANL Sustainable Design GuideONLEDLED
How Do Holiday Lights Work? | Department of Energy
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
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LED Holiday Lights: Festive, Safe, and Efficient! | Department of Energy
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Observed Holiday Aerosol Reduction and Temperature Cooling over East Asia
Gong, Daoyi; Wang, Wenshan; Qian, Yun; Bai, Wenbing; Guo, Yuanxi; Mao, Rui
2014-06-16
The Spring Festival air pollution in China was investigated using the long-term observations from 2001-2012 over 323 stations. During the Spring Festival with nearly half of urban population leaving the cities for holidays, the particulate matter (PM10) concentration is about 24.5?gm-3 (23%) lower than normal days. Associated with the national-wide burning of firework, the PM10 concentration sharply increases to 123.8?gm-3 at Chinese New Year Day (increment of 35%). Similar to PM10, the SO2 and NO2 decrease from high values in normal days to a holiday minimum with reduction of 23.3% and 30.6%, respectively. The NO2 has no peak in New Year Day because of the different emission source. The night mean and minimum temperature co-vary with PM10. Both nighttime mean and minimum temperature decrease by about 2.1°C during the holidays. And in association with the pollution jump at New Year Day the night temperature simultaneously increase by about 0.89°C. The in-phase co-variations between PM10 and night temperature suggest an overall warming effect of holiday aerosol during winter in China.
Delfanti, Alessandro; Castelfranchi, Yurij; Pitrelli, Nico
2009-01-01
his holidays”: exploration, hacking, entrepreneurship in thewith his ideas for “DNA hacking”, which he has presented
HOLIDAY NEWSLETTER DECEMBER 9TH-JANUARY 19TH
Lawrence, Rick L.
. BETTER fOR THE ENvIRONMENT. -MINIMIzE SHIppINg COSTS TIPS FOR BEING SUSTAINABLE THIS HOLIDAY SEASON'S WANTED TO CREATE AN INSpI- RATIONAL AND EDUCATIONAL ART pIECE TO pROMOTE OUR MISSION Of SUSTAINABILITY ELECTRONICS -WATER YOUR pLANTS #12;SUSTAINABILITY IN THE NEWS NEW pLASTIC THAT DISAppEARS WHEN YOU WANT
Energy-Efficient Holiday Decorating Tips | Department of Energy
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
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Museum Closed for New Year's Holiday
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Michelle L. Holiday | Department of Energy
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Summing Planar Bosonic Open Strings
Bardakci, Korkut
2006-02-16
In earlier work, planar graphs of massless {phi}{sup 3} theory were summed with the help of the light cone world sheet picture and the mean field approximation. In the present article, the same methods are applied to the problem of summing planar bosonic open strings. They find that in the ground state of the system, string boundaries form a condensate on the world sheet, and a new string emerges from this summation. Its slope is always greater than the initial slope, and it remains non-zero even when the initial slope is set equal to zero. If they assume the initial string tends to a field a theory in the zero slope limit, this result provides evidence for string formation in field theory.
Energy-Efficient Holiday Decorating Tips | Department of Energy
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G. L. Alberghi
2010-02-19
We describe a possible realization of the spontaneous baryogenesis mechanism in the context of extra-dimensional string cosmology and specifically in the string gas scenario.
Sergio Giardino
2013-05-21
In this article the quantum fluctuation of a rigid and static string is reported to be identical to a free quantum particle. Solutions similar to this static string have already been found in the semi-classical quantizaton of pulsating strings, and our results show that the semi-classical quantization of pulsating strings is, in some cases, a perturbation of static strings. We also interpret the energy of the static string as a lower bound for the pulsating string and speculate about a description of quantum mechanics in terms of semi-classical string theory.
Daniel Schubring; Vitaly Vanchurin
2013-06-02
We consider conserved currents in an interacting network of one-dimensional objects (or strings). Singular currents localized on a single string are considered in general, and a formal procedure for coarse-graining over many strings is developed. This procedure is applied to strings described by the Nambu-Goto action such as cosmic strings. In addition to conserved currents corresponding to the energy-momentum tensor, we consider an antisymmetric tensor of conserved currents related to the string tangent vector. Under the assumption of local equilibrium we derive a complete set of hydrodynamic equations for strings.
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Excitation Fields in a Superconducting Global String
J. R. Morris
1995-09-28
A model of a straight superconducting global cosmic string is examined in a setting wherein the string supports a charge/current pulse described by a travelling wave along the string. Linearized field equations are obtained for fluctuations of the scalar and vector fields of the theory, and a set of approximate particular solutions are found for the case in which the linear charge density and the current of the string have equal magnitudes. Although the equations of motion seem to suggest that the scalar and vector excitation fields are massive inside the string core, the particular solutions show that they behave as effectively massless fields which propagate at the speed of light along the string along with the primary charge/current pulse. The effect of the mass parameter is to modulate the radial profile of the excitation fields. The vector excitation field generates radial and angular components for both the electric and magnetic fields, but the particular solutions do not describe the emission or absorption of electromagnetic radiation from the string.
Jorgensen, Douglas K. (Idaho Falls, ID); Kuhns, Douglass J. (Idaho Falls, ID); Wiersholm, Otto (Idaho Falls, ID); Miller, Timothy A. (Idaho Falls, ID)
1993-01-01
The drill string enclosure consists of six component parts, including; a top bracket, an upper acrylic cylinder, an acrylic drill casing guide, a lower acrylic cylinder, a bottom bracket, and three flexible ducts. The upper acrylic cylinder is optional based upon the drill string length. The drill string enclosure allows for an efficient drill and sight operation at a hazardous waste site.
Jorgensen, D.K.; Kuhns, D.J.; Wiersholm, O.; Miller, T.A.
1993-03-02
The drill string enclosure consists of six component parts, including; a top bracket, an upper acrylic cylinder, an acrylic drill casing guide, a lower acrylic cylinder, a bottom bracket, and three flexible ducts. The upper acrylic cylinder is optional based upon the drill string length. The drill string enclosure allows for an efficient drill and sight operation at a hazardous waste site.
A microscopic description of absorption in high-energy string-brane collisions
D'Appollonio, Giuseppe; Russo, Rodolfo; Veneziano, Gabriele
2015-01-01
We study the collision of a highly energetic light closed string off a stack of Dp-branes at (sub)string-scale impact parameters and in a regime justifying a perturbative treatment. Unlike at larger impact parameters - where elastic scattering and/or tidal excitations dominate - here absorption of the closed string by the brane system, with the associated excitation of open strings living on it, becomes important. As a first step, we study this phenomenon at the disk level, in which the energetic closed string turns into a single heavy open string at rest whose particularly simple properties are described.
A microscopic description of absorption in high-energy string-brane collisions
Giuseppe D'Appollonio; Paolo Di Vecchia; Rodolfo Russo; Gabriele Veneziano
2015-10-13
We study the collision of a highly energetic light closed string off a stack of Dp-branes at (sub)string-scale impact parameters and in a regime justifying a perturbative treatment. Unlike at larger impact parameters - where elastic scattering and/or tidal excitations dominate - here absorption of the closed string by the brane system, with the associated excitation of open strings living on it, becomes important. As a first step, we study this phenomenon at the disk level, in which the energetic closed string turns into a single heavy open string at rest whose particularly simple properties are described.
Neil. D. Lambert; David Tong
1999-07-13
We study two-dimensional SQED viewed as the world-volume theory of a D-string in the presence of D5-branes with non-zero background fields that induce attractive forces between the branes. In various approximations, the low-energy dynamics is given by a hyperKahler, or hyperKahler with torsion, massive sigma-model. We demonstrate the existence of kink solutions corresponding to the string interpolating between different D5-branes. Bound states of the D-string with fundamental strings are identified with Q-kinks which, in turn, are identified with dyonic instanton strings on the D5-brane world-volume.
2 2000-01 Annual Schedule of Classes Veterans' Day honored as holiday
Grether, Gregory
2 2000-01 Annual Schedule of Classes Veterans' Day honored as holiday Beginning Fall Quarter 2000 been approved for the 2000-01 academic year.The Medical Insurance Plan (MIP), which is of- fered://www.registrar.ucla.edu/fees for updated information. Online processing becomes mandatory for MIP waivers Effective Fall Quarter 2000
String Amplitudes from Moyal String Field Theory
I. Bars; I. Kishimoto; Y. Matsuo
2002-12-29
We illustrate a basic framework for analytic computations of Feynman graphs using the Moyal star formulation of string field theory. We present efficient methods of computation based on (a) the monoid algebra in noncommutative space and (b) the conventional Feynman rules in Fourier space. The methods apply equally well to perturbative string states or nonperturbative string states involving D-branes. The ghost sector is formulated using Moyal products with fermionic (b,c) ghosts. We also provide a short account on how the purely cubic theory and/or VSFT proposals may receive some clarification of their midpoint structures in our regularized framework.
Cosmic strings in hidden sectors: 2. Cosmological and astrophysical signatures
Long, Andrew J.; Vachaspati, Tanmay, E-mail: andrewjlong@asu.edu, E-mail: tvachasp@asu.edu [Physics Department, Arizona State University, Tempe, Arizona 85287 (United States)
2014-12-01
Cosmic strings can arise in hidden sector models with a spontaneously broken Abelian symmetry group. We have studied the couplings of the Standard Model fields to these so-called dark strings in the companion paper. Here we survey the cosmological and astrophysical observables that could be associated with the presence of dark strings in our universe with an emphasis on low-scale models, perhaps TeV . Specifically, we consider constraints from nucleosynthesis and CMB spectral distortions, and we calculate the predicted fluxes of diffuse gamma ray cascade photons and cosmic rays. For strings as light as TeV, we find that the predicted level of these signatures is well below the sensitivity of the current experiments, and therefore low scale cosmic strings in hidden sectors remain unconstrained. Heavier strings with a mass scale in the range 10{sup 13} GeV to 10{sup 15} GeV are at tension with nucleosynthesis constraints.
Quantization of a string with attached mass
A. Lewis Licht
2011-08-02
A simple model of a relativistic open string with a point mass attached at one end is quantized. The normal modes are derived and used to construct expressions for the operator commutators. Light cone gauge is used to find the mass squared operator. The singular part of the operator product expansion is derived.
Roberto Iengo; Jorge G. Russo
2006-02-20
We explain simple semi-classical rules to estimate the lifetime of any given highly-excited quantum state of the string spectrum in flat spacetime. We discuss both the decays by splitting into two massive states and by massless emission. As an application, we study a solution describing a rotating and pulsating ellipse which becomes folded at an instant of time -- the ``squashing ellipse''. This string interpolates between the folded string with maximum angular momentum and the pulsating circular string. We explicitly compute the quantum decay rate for the corresponding quantum state, and verify the basic rules that we propose. Finally, we give a more general (4-parameter) family of closed string solutions representing rotating and pulsating elliptical strings.
John H. Schwarz
1995-03-20
A brief review of the status of duality symmetries in string theory is presented. The evidence is accumulating rapidly that an enormous group of duality symmetries, including perturbative T dualities and non-perturbative S-dualities, underlies string theory. It is my hope that an understanding of these symmetries will suggest the right way to formulate non-perturbative string theory. Whether or not this hope is realized, it has already been demonstrated that this line of inquiry leads to powerful new tools for understanding gauge theories and new evidence for the uniqueness of string theory, as well as deep mathematical results.
South Carolina Community Lights Up the Season with Energy-Efficient Holiday
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What Do You Think of Your LED Holiday Lights? | Department of Energy
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Top 5 Things You Didn't Know About Holiday Lights | Department of Energy
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Making Ends Meet: String Unification and Low-Energy Data
Keith R. Dienes; Alon E. Faraggi
1995-10-04
A long-standing problem in string phenomenology has been the fact that the string unification scale disagrees with the GUT scale obtained by extrapolating low-energy data within the framework of the minimal supersymmetric standard model (MSSM). In this paper we examine several effects that may modify the minimal string predictions and thereby bring string-scale unification into agreement with low-energy data. These include heavy string threshold corrections, non-standard hypercharge normalizations, light SUSY thresholds, intermediate gauge structure, and thresholds arising from extra matter beyond the MSSM. We explicitly evaluate these contributions within a variety of realistic free-fermionic string models, including the flipped SU(5), SO(6) x SO(4), and various SU(3) x SU(2) x U(1) models, and find that most of these sources do not substantially alter the minimal string predictions. Indeed, we find that the only way to reconcile string unification with low-energy data is through certain types of extra matter. Remarkably, however, many of the realistic string models contain precisely this required matter in their low-energy spectra.
Holiday Gifts for Energy Efficiency | 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 Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirley Ann JacksonDepartment ofOffice ofofWindUpcomingcanGrid Integrationheat WhatDot Harris2015light
Meaningful Money Gifts at Holiday Time | The Ames Laboratory
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Amore, Paolo; Fernández, Francisco M.; Garcia, Javier; Gutierrez, German
2014-04-15
We study both analytically and numerically the spectrum of inhomogeneous strings with PT-symmetric density. We discuss an exactly solvable model of PT-symmetric string which is isospectral to the uniform string; for more general strings, we calculate exactly the sum rules Z(p)??{sub n=1}{sup ?}1/E{sub n}{sup p}, with p=1,2,… and find explicit expressions which can be used to obtain bounds on the lowest eigenvalue. A detailed numerical calculation is carried out for two non-solvable models depending on a parameter, obtaining precise estimates of the critical values where pair of real eigenvalues become complex. -- Highlights: •PT-symmetric Hamiltonians exhibit real eigenvalues when PT symmetry is unbroken. •We study PT-symmetric strings with complex density. •They exhibit regions of unbroken PT symmetry. •We calculate the critical parameters at the boundaries of those regions. •There are exact real sum rules for some particular complex densities.
Weigel, H. [Physics Department, Stellenbosch University, Matieland 7602 (South Africa); Quandt, M. [Institute for Theoretical Physics, Tuebingen University, D-72076 Tuebingen (Germany); Graham, N. [Department of Physics, Middlebury College , Middlebury, Vermont 05753 (United States)
2011-03-11
We study the quantum stabilization of a cosmic string by a heavy fermion doublet in a reduced version of the standard model. We show that charged strings, obtained by populating fermionic bound state levels, become stable if the electroweak bosons are coupled to a fermion that is less than twice as heavy as the top quark. This result suggests that extraordinarily large fermion masses or unrealistic couplings are not required to bind a cosmic string in the standard model. Numerically we find the most favorable string profile to be a simple trough in the Higgs vacuum expectation value of radius {approx_equal}10{sup -18} m. The vacuum remains stable in our model, because neutral strings are not energetically favored.
Grassmannian and string theory
Albert Schwarz
1996-12-02
Infinite-dimensional Grassmannian manifold contains moduli spaces of Riemann surfaces of all genera. This well known fact leads to a conjecture that non-perturbative string theory can be formulated in terms of Grassmannian. We present new facts supporting this hypothesis. In particular, it is shown that Grassmannians can be considered as generalized moduli spaces; this statement permits us to define corresponding "string amplitudes" (at least formally). One can conjecture, that it is possible to explain the relation between non-perturbative and perturbative string theory by means of localization theorems for equivariant cohomology; this conjecture is based on the characterization of moduli spaces, relevant to string theory, as sets consisting of points with large stabilizers in certain groups acting on Grassmannian. We describe an involution on the Grassmannian that could be related to S-duality in string theory.
Reheating and Cosmic String Production
Chao-Jun Feng; Xian Gao; Miao Li; Wei Song; Yushu Song
2008-01-04
We compute the string production rate at the end of inflation, using the string spectrum obtained in \\lss in a near-de Sitter space. Our result shows that highly excited strings are hardly produced, thus the simple slow-roll inflation alone does not offer a cosmic string production mechanism.
Extended Inflation from Strings
J. Garcia-Bellido; M. quiros
1991-09-25
We study the possibility of extended inflation in the effective theory of gravity from strings compactified to four dimensions and find that it strongly depends on the mechanism of supersymmetry breaking. We consider a general class of string--inspired models which are good candidates for successful extended inflation. In particular, the $\\omega$--problem of ordinary extended inflation is automatically solved by the production of only very small bubbles until the end of inflation. We find that the inflaton field could belong either to the untwisted or to the twisted massless sectors of the string spectrum, depending on the supersymmetry breaking superpotential.
PhD Thesis: String theory in the early universe
Rhiannon Gwyn
2009-11-14
The intersection of string theory with cosmology is unavoidable in the early universe, and its exploration may shine light on both fields. In this thesis, three papers at this intersection are presented and reviewed, with the aim of providing a thorough and pedagogical guide to their results. First, we address the longstanding problem of finding a string theory realisation of the axion. Using warped compactifications in heterotic string theory, we show that the axion decay constant can be lowered to acceptable values by the warp factor. Next, we move to the subject of cosmic strings, whose network evolution could have important consequences for astrophysics and cosmology. In particular, there are quantitative differences between cosmic superstring networks and GUT cosmic string networks. We investigate the properties of cosmic superstring networks in warped backgrounds, giving the tension and properties of three-string junctions in these backgrounds. Finally, we examine the possibility that cosmic strings in heterotic string theory could be responsible for generating the galactic magnetic fields that seeded those observed today.
Shooting string holography of jet quenching at RHIC and LHC
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Ficnar, Andrej; Gubser, Steven S.; Gyulassy, Miklos
2014-10-13
We derive a new formula for jet energy loss using finite endpoint momentum shooting strings initial conditions in SYM plasmas to overcome the difficulties of previous falling string holographic scenarios. We apply the new formula to compute the nuclear modification factor RAA and the elliptic flow parameter v2 of light hadrons at RHIC and LHC. We show furthermore that Gauss–Bonnet quadratic curvature corrections to the AdS5 geometry improve the agreement with the recent data.
Fusion of strings and cosmic rays at ultrahigh energies
N. Armesto; M. A. Braun; E. G. Ferreiro; C. Pajares; Yu. M. Shabelski
1996-02-13
It is shown that the fusion of strings is a source of particle production in nucleus--nucleus collisions outside the kinematical limits of nucleon--nucleon collisions. This fact, together with another effect of string fusion, the reduction of multiplicities, sheds some light on two of the main problems of ultrahigh energy cosmic rays, the chemical composition and the energy of the most energetic detected cosmic rays.
Casper, William L. (Rigby, ID); Clark, Don T. (Idaho Falls, ID); Grover, Blair K. (Idaho Falls, ID); Mathewson, Rodney O. (Idaho Falls, ID); Seymour, Craig A. (Idaho Falls, ID)
2008-10-07
A drill string comprises a first drill string member having a male end; and a second drill string member having a female end configured to be joined to the male end of the first drill string member, the male end having a threaded portion including generally square threads, the male end having a non-threaded extension portion coaxial with the threaded portion, and the male end further having a bearing surface, the female end having a female threaded portion having corresponding female threads, the female end having a non-threaded extension portion coaxial with the female threaded portion, and the female end having a bearing surface. Installation methods, including methods of installing instrumented probes are also provided.
Hydroball string sensing system
Hurwitz, Michael J. (Pittsburgh, PA); Ekeroth, Douglas E. (Delmont, PA); Squarer, David (Pittsburgh, PA)
1991-01-01
A hydroball string sensing system for a nuclear reactor that includes stainless tubes positioned to guide hydroball strings into and out of the nuclear reactor core. A sensor such as an ultrasonic transducer transmitter and receiver is positioned outside of the nuclear reactor core and adjacent to the tube. The presence of an object such a bullet member positioned at an end a hydroball string, or any one of the hydroballs interrupts the transmission of ultrasound from the transmitter to the receiver. Alternatively, if the bullet member and hydroballs include a ferritic material, either a Hall effect sensor or other magnetic field sensors such as a magnetic field rate of change sensor can be used to detect the location and position of a hydroball string. Placing two sensors along the tube with a known distance between the sensors enables the velocity of a hydroball string to be determined. This determined velocity can be used to control the flow rate of a fluid within the tube so as to control the velocity of the hydroball string.
It's Finally Time to Think about the Holidays! | Department of Energy
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#tipsEnergy: How to Save Energy During the Holidays | Department of Energy
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String Theory: Progress and Problems
John H. Schwarz
2007-03-05
String theory builds on the great legacy of Yukawa and Tomonaga: New degrees of freedom and control of the UV are two important themes. This talk will give an overview of some of the progress and some of the unsolved problems that characterize string theory today. It is divided into two parts: (1) Connecting String Theory to the Real World; (2) Gauge Theory/String Theory Duality. Two other major subjects, which I will omit, are Black Holes in String Theory and The Impact of String Theory on Mathematics.
Elliptic flow from color strings
M. A. Braun; C. Pajares
2010-08-02
It is shown that the elliptic flow can be successfully described in the color string picture with fusion and percolation provided anisotropy of particle emission from the fused string is taken into account. Two possible sources of this anisotropy are considered, propagation of the string in the transverse plane and quenching of produced particles in the strong color field of the string. Calculations show that the second source gives an overwhelming contribution to the flow at accessible energies.
Reasonover, Frances L.; Sweeten, Mary K.
1981-01-01
small onion, chopped 2 tablespoons margarine 1 can cream of mushroom soup 1 6-ounce roll garlic cheese. 1/2 teaspoon salt 1/8 teaspoon pepper 1/8 teaspoon hot sauce 1 teaspoon Worcestershire sauce 1 4-ounce can mushrooms, stems and pieces.... Stir occasionally to mix ingredients. Add mushrooms and almonds. Serve hot with chips or crisp crackers. Makes 4 cups. CAVIAR MOLD 1 envelope (1 tablespoon) plain gelatin 2 tablespoons cold water 2 tablespoons lemon juice 1 cup mayonnaise 6...
Miftachul Hadi; Malcolm Anderson; Andri Husein
2014-05-07
We study nonlinear sigma model, especially Skyrme model without twist and Skyrme model with twist: twisted Skyrmion string. Twist term, $mkz$, is indicated in vortex solution. Necessary condition for stability of vortex solution has consequence that energy of vortex is minimum and scale-free (vortex solution is neutrally stable to changes in scale). We find numerically that the value of vortex minimum energy per unit length for twisted Skyrmion string is $20.37\\times 10^{60}~\\text{eV/m}$.
Keith Dienes
2010-01-08
We are currently in the throes of a potentially huge paradigm shift in physics. Motivated by recent developments in string theory and the discovery of the so-called "string landscape", physicists are beginning to question the uniqueness of fundamental theories of physics and the methods by which such theories might be understood and investigated. In this colloquium, I will give a non-technical introduction to the nature of this paradigm shift and how it developed. I will also discuss some of the questions to which it has led, and the nature of the controversies it has spawned.
Double Wick rotating Green-Schwarz strings
Gleb Arutyunov; Stijn J. van Tongeren
2015-05-05
Via an appropriate field redefinition of the fermions, we find a set of conditions under which light cone gauge fixed world sheet theories of strings on two different backgrounds are related by a double Wick rotation. These conditions take the form of a set of transformation laws for the background fields, complementing a set of transformation laws for the metric and B field we found previously with a set for the dilaton and RR fields, and are compatible with the supergravity equations of motion. Our results prove that at least to second order in fermions, the AdS_5 x S^5 mirror model which plays an important role in the field of integrability in AdS/CFT, represents a string on `mirror AdS_5 x S^5', the background that follows from our transformations. We discuss analogous solutions for AdS_3 x S^3 x T^4 and AdS_2 x S^2 x T^6. The main ingredient in our derivation is the light cone gauge fixed action for a string on an (almost) completely generic background, which we explicitly derive to second order in fermions.
Current balancing for battery strings
Galloway, James H. (New Baltimore, MI)
1985-01-01
A battery plant is described which features magnetic circuit means for balancing the electrical current flow through a pluraliircuitbattery strings which are connected electrically in parallel. The magnetic circuit means is associated with the battery strings such that the conductors carrying the electrical current flow through each of the battery strings pass through the magnetic circuit means in directions which cause the electromagnetic fields of at least one predetermined pair of the conductors to oppose each other. In an alternative embodiment, a low voltage converter is associated with each of the battery strings for balancing the electrical current flow through the battery strings.
Loginov, E. K.
2008-05-15
We consider generalized self-duality equations for U(2r) Yang-Mills theory on R{sup 8} with quaternionic structure. We employ the extended ADHM method in eight dimensions to construct exact soliton solutions of the low-energy effective theory of the heterotic string.
John H. Schwarz
2003-04-28
The first part of this report gives a very quick sketch of how string theory concepts originated and evolved during its first 25 years (1968-93). The second part presents a somewhat more detailed discussion of the highlights of the past decade. The final part discusses some of the major problems that remain to be solved.
Device for balancing parallel strings
Mashikian, Matthew S. (Storrs, CT)
1985-01-01
A battery plant is described which features magnetic circuit means in association with each of the battery strings in the battery plant for balancing the electrical current flow through the battery strings by equalizing the voltage across each of the battery strings. Each of the magnetic circuit means generally comprises means for sensing the electrical current flow through one of the battery strings, and a saturable reactor having a main winding connected electrically in series with the battery string, a bias winding connected to a source of alternating current and a control winding connected to a variable source of direct current controlled by the sensing means. Each of the battery strings is formed by a plurality of batteries connected electrically in series, and these battery strings are connected electrically in parallel across common bus conductors.
A merged two-stage converter for LED lighting applications
Ranson, John (John David)
2012-01-01
Light Emitting Diodes (LEDs) are a very promising technology for developing more efficient lighting. For high-efficiency applications, a switching current regulator is necessary to control the power drawn by an LED string. ...
Coulomb string tension, asymptotic string tension, and the gluon chain
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Greensite, Jeff; Szczepaniak, Adam P.
2015-02-01
We compute, via numerical simulations, the non-perturbative Coulomb potential and position-space ghost propagator in pure SU(3) gauge theory in Coulomb gauge. We find that that the Coulomb potential scales nicely in accordance with asymptotic freedom, that the Coulomb potential is linear in the infrared, and that the Coulomb string tension is about four times larger than the asymptotic string tension. We explain how it is possible that the asymptotic string tension can be lower than the Coulomb string tension by a factor of four.
String melting in a photon bath
Karouby, Johanna, E-mail: karoubyj@mit.edu [Center for Theoretical Physics and Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachussetts 02139 (United States)
2013-10-01
We compute the decay rate of a metastable cosmic string in contact with a thermal bath by finding the instanton solution. The new feature is that this decay rate is found in the context of non thermal scalar fields in contact with a thermal bath of photons. In general, to make topologically unstable strings stable, one can couple them to such a bath. The resulting plasma effect creates metastable configurations which can decay from the false vacuum to the true vacuum. In our specific set-up, the instanton computation is realized for the case of two out-of-equilibrium complex scalar fields: one is charged and coupled to the photon field, and the other is neutral. New effects coming from the thermal bath of photons make the radius of the nucleated bubble and most of the relevant physical quantities temperature-dependent. However, the temperature appears in a different way than in the purely thermal case, where all scalar fields are in thermal equilibrium. As a result of the tunneling, the core of the initial string melts while bubbles of true vacuum expand at the speed of light.
Physics of String Flux Compactifications
Frederik Denef; Michael R. Douglas; Shamit Kachru
2007-01-06
We provide a qualitative review of flux compactifications of string theory, focusing on broad physical implications and statistical methods of analysis.
The SSC Full Cell Prototype String Test
McInturff, A.D.
2011-01-01
the Proceedings The SSC Full Cell Prototype String Test A.D.AC03-76SFOOO98. The SSC Full Cell Prototype String Test P.the Proceedings The SSC Full Cell Prototype String Test A.D.
Ramakrishnan Iyer; Clifford V. Johnson; Jeffrey S. Pennington
2010-02-05
We uncover a remarkable role that an infinite hierarchy of non-linear differential equations plays in organizing and connecting certain {hat c}water wave hierarchy. We observe that there are several other string-like limits of the system, and conjecture that some of them are type IIA and IIB (A,D) minimal string backgrounds. We explain how these and several string-like special points arise and are connected. In some cases, the framework endows the theories with a non-perturbative definition for the first time. Notably, we discover that the Painleve IV equation plays a key role in organizing the string theory physics, joining its siblings, Painleve I and II, whose roles have previously been identified in this minimal string context.
String-theoretic breakdown of effective field theory near black hole horizons
Dodelson, Matthew
2015-01-01
We investigate the validity of the equivalence principle near horizons in string theory, analyzing the breakdown of effective field theory caused by longitudinal string spreading effects. An experiment is set up where a detector is thrown into a black hole a long time after an early infalling string. Light cone gauge calculations, taken at face value, indicate a detectable level of root-mean-square longitudinal spreading of the initial string as measured by the late infaller. This results from the large relative boost between the string and detector in the near horizon region, which develops automatically despite their modest initial energies outside the black hole and the weak curvature in the geometry. We subject this scenario to basic consistency checks, using these to obtain a relatively conservative criterion for its detectability. In a companion paper, we exhibit longitudinal nonlocality in well-defined gauge-invariant S-matrix calculations, obtaining results consistent with the predicted spreading albe...
Large scale CMB anomalies from thawing cosmic strings
Ringeval, Christophe; Yokoyama, Jun'ichi; Bouchet, Francois R
2015-01-01
Cosmic strings formed during inflation are expected to be either diluted over super-Hubble distances, i.e., invisible today, or to have crossed our past light cone very recently. We discuss the latter situation in which a few strings imprint their signature in the Cosmic Microwave Background (CMB) Anisotropies after recombination. Being almost frozen in the Hubble flow, these strings are quasi static and evade almost all of the previously derived constraints on their tension while being able to source large scale anisotropies in the CMB sky. Using a local variance estimator on thousand of numerically simulated Nambu-Goto all sky maps, we compute the expected signal and show that it can mimic a dipole modulation at large angular scales while being negligible at small angles. Interestingly, such a scenario generically produces one cold spot from the thawing of a cosmic string loop. Mixed with anisotropies of inflationary origin, we find that a few strings of tension GU = O(1) x 10^(-6) match the amplitude of th...
Large scale CMB anomalies from thawing cosmic strings
Christophe Ringeval; Daisuke Yamauchi; Jun'ichi Yokoyama; Francois R. Bouchet
2015-10-07
Cosmic strings formed during inflation are expected to be either diluted over super-Hubble distances, i.e., invisible today, or to have crossed our past light cone very recently. We discuss the latter situation in which a few strings imprint their signature in the Cosmic Microwave Background (CMB) Anisotropies after recombination. Being almost frozen in the Hubble flow, these strings are quasi static and evade almost all of the previously derived constraints on their tension while being able to source large scale anisotropies in the CMB sky. Using a local variance estimator on thousand of numerically simulated Nambu-Goto all sky maps, we compute the expected signal and show that it can mimic a dipole modulation at large angular scales while being negligible at small angles. Interestingly, such a scenario generically produces one cold spot from the thawing of a cosmic string loop. Mixed with anisotropies of inflationary origin, we find that a few strings of tension GU = O(1) x 10^(-6) match the amplitude of the dipole modulation reported in the Planck satellite measurements and could be at the origin of other large scale anomalies.
Strings, higher curvature corrections, and black holes
Thomas Mohaupt
2005-12-05
We review old and recent results on subleading contributions to black hole entropy in string theory.
Emergence String and Mass Formulas of Hadrons
Yi-Fang Chang
2011-07-19
Assume that hadrons are formed from the emergence string. Usual string should possess two moving states: oscillation and rotation, so we propose corresponding potential and the equation of the emergence string, whose energy spectrum is namely the GMO mass formula and its modified accurate mass formula. These are some relations between the string and observable experimental data.
Radio bursts from superconducting strings
Yi-Fu Cai; Eray Sabancilar; Tanmay Vachaspati
2012-01-30
We show that radio bursts from cusps on superconducting strings are linearly polarized, thus, providing a signature that can be used to distinguish them from astrophysical sources. We write the event rate of string-generated radio transients in terms of observational variables, namely, the event duration and flux. Assuming a canonical set of observational parameters, we find that the burst event rate can be quite reasonable, e.g., order ten a year for Grand Unified strings with 100 TeV currents, and a lack of observed radio bursts can potentially place strong constraints on particle physics models.
Radio Broadcasts from Superconducting Strings
Yi-Fu Cai; Eray Sabancilar; Daniele A. Steer; Tanmay Vachaspati
2012-05-14
Superconducting cosmic strings can give transient electromagnetic signatures that we argue are most evident at radio frequencies. We investigate the three different kinds of radio bursts from cusps, kinks, and kink-kink collisions on superconducting strings. We find that the event rate is dominated by kink bursts in a range of parameters that are of observational interest, and can be quite high (several a day at 1 Jy flux) for a canonical set of parameters. In the absence of events, the search for radio transients can place stringent constraints on superconducting cosmic strings.
Worldsheet Geometries of Ambitwistor String
Kantaro Ohmori
2015-06-12
Mason and Skinner proposed the ambitwistor string theory which directly reproduces the formulas for the amplitudes of massless particles proposed by Cachazo, He and Yuan. In this paper we discuss geometries of the moduli space of worldsheets associated to the bosonic or the RNS ambitwistor string. Further, we investigate the factorization properties of the amplitudes when an internal momentum is near on-shell in the abstract CFT language. Along the way, we propose the existence of the ambitwistor strings with three or four fermionic worldsheet currents.
Worldsheet Geometries of Ambitwistor String
Ohmori, Kantaro
2015-01-01
Mason and Skinner proposed the ambitwistor string theory which directly reproduces the formulas for the amplitudes of massless particles proposed by Cachazo, He and Yuan. In this paper we discuss geometries of the moduli space of worldsheets associated to the bosonic or the RNS ambitwistor string. Further, we investigate the factorization properties of the amplitudes when an internal momentum is near on-shell in the abstract CFT language. Along the way, we propose the existence of the ambitwistor strings with three or four fermionic worldsheet currents.
M-strings, Elliptic Genera and N=4 String Amplitudes
Stefan Hohenegger; Amer Iqbal
2014-03-11
We study mass-deformed N=2 gauge theories from various points of view. Their partition functions can be computed via three dual approaches: firstly, (p,q)-brane webs in type II string theory using Nekrasov's instanton calculus, secondly, the (refined) topological string using the topological vertex formalism and thirdly, M theory via the elliptic genus of certain M-strings configurations. We argue for a large class of theories that these approaches yield the same gauge theory partition function which we study in detail. To make their modular properties more tangible, we consider a fourth approach by connecting the partition function to the equivariant elliptic genus of R^4 through a (singular) theta-transform. This form appears naturally as a specific class of one-loop scattering amplitudes in type II string theory on T^2, which we calculate explicitly.
Reheating Closed String Inflation
Daniel Green
2007-10-02
Protecting the inflationary potential from quantum corrections typically requires symmetries that constrain the form of couplings of the inflaton to other sectors. We will explore how these restrictions affect reheating in models with UV completions. In particular, we look at how reheating occurs when inflation is governed by closed strings, using N-flation as an example. We find that coupling the inflaton preferentially to the Standard Model is difficult, and hidden sectors are typically reheated. Observational constraints are only met by a fraction of the models. In some working models, relativistic relics in the hidden sector provide dark matter candidates with masses that range from keV to PeV, with lighter masses being preferred.
Multi-loop open string amplitudes and their field theory limit
Lorenzo Magnea; Sam Playle; Rodolfo Russo; Stefano Sciuto
2015-03-19
We study the field theory limit of multi-loop (super)string amplitudes, with the aim of clarifying their relationship to Feynman diagrams describing the dynamics of the massless states. We propose an explicit map between string moduli around degeneration points and Schwinger proper-times characterizing individual Feynman diagram topologies. This makes it possible to identify the contribution of each light string state within the full string amplitude and to extract the field theory Feynman rules selected by (covariantly quantized) string theory. The connection between string and field theory amplitudes also provides a concrete tool to clarify ambiguities related to total derivatives over moduli space: in the superstring case, consistency with the field theory results selects a specific prescription for integrating over supermoduli. In this paper, as an example, we focus on open strings supported by parallel D-branes, and we present two-loop examples drawn from bosonic and RNS string theories, highlighting the common features between the two setups.
String Theory: The Early Years
John H. Schwarz
2000-07-26
Lenny Susskind has made many important contributions to theoretical physics during the past 35 years. In this talk I will discuss the early history of string theory (1968-72) emphasizing Susskind's contributions.
String Theory Origins of Supersymmetry
John H. Schwarz
2000-11-09
The string theory introduced in early 1971 by Ramond, Neveu, and myself has two-dimensional world-sheet supersymmetry. This theory, developed at about the same time that Golfand and Likhtman constructed the four-dimensional super-Poincar\\'e algebra, motivated Wess and Zumino to construct supersymmetric field theories in four dimensions. Gliozzi, Scherk, and Olive conjectured the spacetime supersymmetry of the string theory in 1976, a fact that was proved five years later by Green and myself.
Quark Propagator and Chiral Symmetry with String Tension
Anishetty, R; Anishetty, Ramesh; Kudtarkar, Santosh Kumar
2003-01-01
General properties of the light and heavy quark propagators have been investigated in the context of string tension interaction. Confinement, chiral symmetry breaking, spectral properties of the propagator are analytically studied and numerically validated. We show that the propagator is analytic in the infrared region even for massless quarks with a non zero radius of convergence. Emergence of more than one mass scale is exemplified. Massless limit of the quark propagator does exhibit critical behaviour.
Results on exact solutions of low energy string theory
David Garfinkle
1992-10-31
A family of solutions to low energy string theory is found. These solutions represent waves traveling along "extremal black strings"
Acoustic data transmission through a drill string
Drumheller, D.S.
1988-04-21
Acoustical signals are transmitted through a drill string by canceling upward moving acoustical noise and by preconditioning the data in recognition of the comb filter impedance characteristics of the drill string. 5 figs.
Metastable cosmic strings in realistic models
Holman, R.; Hsu, S.; Vachaspati, T.; Watkins, R. |
1992-11-01
The stability of the electroweak Z-string is investigated at high temperatures. The results show that, while finite temperature corrections can improve the stability of the Z-string, their effect is not strong enough to stabilize the Z-string in the standard electroweak model. Consequently, the Z-string will be unstable even under the conditions present during the electroweak phase transition. Phenomenologically viable models based on the gauge group SU(2){sub L} {times} SU(2) {sub R} {times} U(1){sub B-L} are then considered, and it is shown that metastable strings exist and are stable to small perturbations for a large region of the parameter space for these models. It is also shown that these strings are superconducting with bosonic charge carriers. The string superconductivity may be able to stabilize segments and loops against dynamical contraction. Possible implications of these strings for cosmology are discussed.
Metastable cosmic strings in realistic models
Holman, R. . Dept. of Physics); Hsu, S. . Lyman Lab. of Physics); Vachaspati, T. . Dept. of Physics and Astronomy); Watkins, R. Fermi National Accelerator Lab., Batavia, IL )
1992-01-01
The stability of the electroweak Z-string is investigated at high temperatures. The results show that, while finite temperature corrections can improve the stability of the Z-string, their effect is not strong enough to stabilize the Z-string in the standard electroweak model. Consequently, the Z-string will be unstable even under the conditions present during the electroweak phase transition. Phenomenologically viable models based on the gauge group SU(2)[sub L] [times] SU(2) [sub R] [times] U(1)[sub B-L] are then considered, and it is shown that metastable strings exist and are stable to small perturbations for a large region of the parameter space for these models. It is also shown that these strings are superconducting with bosonic charge carriers. The string superconductivity may be able to stabilize segments and loops against dynamical contraction. Possible implications of these strings for cosmology are discussed.
Quadratic superconducting cosmic strings revisited
Mustapha Azreg-Aïnou
2008-02-22
It has been shown that 5-dimensional general relativity action extended by appropriate quadratic terms admits a singular superconducting cosmic string solution. We search for cosmic strings endowed with similar and extended physical properties by directly integrating the non-linear matrix field equations thus avoiding the perturbative approach by which we constructed the above-mentioned \\textsl{exact} solution. The most general superconducting cosmic string, subject to some constraints, will be derived and shown to be mathematically \\textsl{unique} up to linear coordinate transformations mixing its Killing vectors. The most general solution, however, is not globally equivalent to the old one due to the existence of Killing vectors with closed orbits.
Wireless Access Testbed through Visible Light and Dimming Compatible OFDM
Little, Thomas
of driving a string of light-emitting diodes (LEDs) using a RPO-OFDM signal is proposed. The driver support by the National Science Foundation under Grant No. EEC-0812056. #12;2 1. Introduction The light-emitting diode (LED) is considered a dominant light source for future indoor as well as outdoor illumination
Closed/open string diagrammatics
2006-06-28
May 3, 2006 ... In terms of open/closed theories beyond the topological level, many interesting results have ... The rough idea is that as the strings move and interact, they form the leaves .... center (or knowledge)” equations, hold for the c/o structure on ..... ponent, subject to the unique constraint that m1 + m2 + m3 is even.
Scaling behavior of regularized bosonic strings
Jan Ambjorn; Yuri Makeenko
2015-10-12
We implement a proper-time UV regularisation of the Nambu-Goto string, introducing an independent metric tensor and the corresponding Lagrange multiplier, and treating them in the mean-field approximation justified for long strings and/or when the dimensions of space-time is large. We compute the regularised determinant of the 2d Laplacian for the closed string winding around a compact dimension, obtaining in this way the effective action, whose minimisation determines the energy of the string ground state in the mean-field approximation. We discuss the existence of two scaling limits when the cutoff is taken to infinity. One scaling limit reproduces the results obtained by the hypercubic regularisation of the Nambu-Goto string as well as by the use of the dynamical triangulation regularisation of the Polyakov string. The other scaling limit reproduces the results obtained by canonical quantisation of the Nambu-Goto string.
Hall, David R. (Provo, UT); Pixton, David S. (Lehi, UT); Briscoe, Michael (Lehi, UT); McPherson, James (Sandy, UT)
2007-12-04
A filter for a drill string comprises a perforated receptacle having an open end and a perforated end and first and second mounting surfaces are adjacent the open end. A transmission element is disposed within each of the first and second mounting surfaces. A capacitor may modify electrical characteristics of an LC circuit that comprises the transmission elements. The respective transmission elements are in communication with each other and with a transmission network integrated into the drill string. The transmission elements may be inductive couplers, direct electrical contacts, or optical couplers. In some embodiments of the present invention, the filter comprises an electronic component. The electronic component may be selected from the group consisting of a sensor, a router, a power source, a clock source, a repeater, and an amplifier.
String theory and integrable systems
Nissimov, Emil R; Nissimov, Emil; Pacheva, Svetlana
1993-01-01
This is mainly a brief review of some key achievements in a `hot'' area of theoretical and mathematical physics. The principal aim is to outline the basic structures underlying {\\em integrable} quantum field theory models with {\\em infinite-dimensional} symmetry groups which display a radically new type of {\\em quantum group} symmetries. Certain particular aspects are elaborated upon with some detail: integrable systems of Kadomtsev-Petviashvili type and their reductions appearing in matrix models of strings; Hamiltonian approach to Lie-Poisson symmetries; quantum field theory approach to two-dimensional relativistic integrable models with dynamically broken conformal invariance. All field-theoretic models in question are of primary relevance to diverse branches of physics ranging from nonlinear hydrodynamics to string theory of fundamental particle interactions at ultra-high energies.
Eisenstein Series in String Theory
N. A. Obers; B. Pioline
2000-03-01
We discuss the relevance of Eisenstein series for representing certain G(Z)-invariant string theory amplitudes which receive corrections from BPS states only. The Eisenstein series are constructed using G(Z)-invariant mass formulae and are manifestly invariant modular functions on the symmetric space K\\G(R) of non-compact type, with K the maximal compact subgroup of G(R). In particular, we show how Eisenstein series of the T-duality group SO(d,d,Z) can be used to represent one- and g-loop amplitudes in compactified string theory. We also obtain their non-perturbative extensions in terms of the Eisenstein series of the U-duality group E_{d+1(d+1)}(Z).
Nuclear Force from String Theory
Koji Hashimoto; Tadakatsu Sakai; Shigeki Sugimoto
2010-03-09
We compute nuclear force in a holographic model of QCD on the basis of a D4-D8 brane configuration in type IIA string theory. Repulsive core of nucleons is quite important in nuclear physics, but its origin has not been well-understood in strongly-coupled QCD. We find that string theory via gauge/string duality deduces this repulsive core at short distance between nucleons. Since baryons in the model are realized as solitons given by Yang-Mills instanton configuration on flavor D8-branes, ADHM construction of two instantons probes well the nucleon interaction at short scale, which provides the nuclear force quantitatively. We obtain, as well as a tensor force, a central force which is strongly repulsive as suggested in experiments and lattice results. In particular, the nucleon-nucleon potential V(r) (as a function of the distance) scales as 1/r^2, which is peculiar to the holographic model. We compare our results with one-boson exchange model using the nucleon-nucleon-meson coupling obtained in our previous paper (arXiv:0806.3122).
Loop Gas Model for Open Strings
V. Kazakov; I. Kostov
1992-05-18
The open string with one-dimensional target space is formulated in terms of an SOS, or loop gas, model on a random surface. We solve an integral equation for the loop amplitude with Dirichlet and Neumann boundary conditions imposed on different pieces of its boundary. The result is used to calculate the mean values of order and disorder operators, to construct the string propagator and find its spectrum of excitations. The latter is not sensible neither to the string tension $\\L$ nor to the mass $\\mu$ of the ``quarks'' at the ends of the string. As in the case of closed strings, the SOS formulation allows to construct a Feynman diagram technique for the string interaction amplitudes.
Gamma Ray Bursts from Ordinary Cosmic Strings
R. H. Brandenberger; A. T. Sornborger; M. Trodden
1993-02-12
We give an upper estimate for the number of gamma ray bursts from ordinary (non-superconducting) cosmic strings expected to be observed at terrestrial detectors. Assuming that cusp annihilation is the mechanism responsible for the bursts we consider strings arising at a GUT phase transition and compare our estimate with the recent BATSE results. Further we give a lower limit for the effective area of future detectors designed to detect the cosmic string induced flux of gamma ray bursts.
$O(d,d)$-Covariant String Cosmology
M. Gasperini; G. Veneziano
1991-12-17
The recently discovered $O(d,d)$ symmetry of the space of slowly varying cosmological string vacua in $d+1$ dimensions is shown to be preserved in the presence of bulk string matter. The existence of $O(d,d)$ conserved currents allows all the equations of string cosmology to be reduced to first-order differential equations. The perfect-fluid approximation is not $O(d,d)$-invariant, implying that stringy fluids possess in general a non-vanishing viscosity.
Gauge Transformations in String Field Theory and canonical Transformation in String Theory
J. Maharana; S. mukherji
1992-01-24
We study how canonical transfomations in first quantized string theory can be understood as gauge transformations in string field theory. We establish this fact by working out some examples. As a by product, we could identify some of the fields appearing in string field theory with their counterparts in the $\\sigma$-model.
Naohiro Kanda
2011-06-03
For a long time, it is believed that the light by light scattering is described properly by the Lagrangian density obtained by Heisenberg and Euler. Here, we present a new calculation which is based on the modern field theory technique. It is found that the light-light scattering is completely different from the old expression. The reason is basically due to the unphysical condition (gauge condition) which was employed by the QED calcualtion of Karplus and Neumann. The correct cross section of light-light scattering at low energy of $(\\frac{\\omega}{m} \\ll 1)$ can be written as $ \\displaystyle{\\frac{d\\sigma}{d\\Omega}=\\frac{1}{(6\\pi)^2}\\frac{\\alpha^4} {(2\\omega)^2}(3+2\\cos^2\\theta +\\cos^4\\theta)}$.
The Three-String Vertex for a Plane-Wave Background
John H. Schwarz
2003-12-23
The three string vertex for Type IIB superstrings in a maximally supersymmetric plane-wave background can be constructed in a light-cone gauge string field theory formalism. The detailed formula contains certain Neumann coefficients, which are functions of a momentum fraction y and a mass parameter \\mu. This paper reviews the derivation of useful explicit expressions for these Neumann coefficients generalizing flat-space (\\mu = 0) results obtained long ago. These expressions are then used to explore the large \\mu asymptotic behavior, which is required for comparison with dual perturbative gauge theory results. The asymptotic formulas, exact up to exponentially small corrections, turn out to be surprisingly simple.
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Big-Bang Nucleosynthesis and Gamma-Ray Constraints on Cosmic Strings with a large Higgs condensate
H. F. Santana Mota; Mark Hindmarsh
2015-01-06
We consider constraints on cosmic strings from their emission of Higgs particles, in the case that the strings have a Higgs condensate with amplitude of order the string mass scale, assuming that a fraction of the energy of condensate can be turned into radiation near cusps. The injection of energy by the decaying Higgs particles affects the light element abundances predicted by standard Big-Bang Nucleosynthesis (BBN), and also contributes to the Diffuse Gamma-Ray Background (DGRB) in the universe today. We examine the two main string scenarios (Nambu-Goto and field theory), and find that the primordial Helium abundance strongly constrains the string tension and the efficiency of the emission process in the NG scenario, while the strongest BBN constraint in the FT scenario comes from the Deuterium abundance. The Fermi-LAT measurement of the DGRB constrains the field theory scenario even more strongly than previously estimated from EGRET data, requiring that the product of the string tension {\\mu} and Newton's constant G is bounded by G{\\mu} < 2.7x10^{-11}{\\beta}_{ft}^{-2}, where {\\beta}_{ft}^2 is the fraction of the strings' energy going into Higgs particles.
Extraordinary vacuum black string solutions
Kim, Hyeong-Chan; Lee, Jungjai
2008-01-15
In addition to the boosted static solution there are two other classes of stationary stringlike solutions of the vacuum Einstein equation in (4+1) dimensions. Each class is characterized by three parameters of mass, tension, and momentum flow along the fifth coordinate. We analyze the metric properties of one of the two classes, which was previously assumed to be naked singular, and show that the solution spectrum contains black string and wormhole in addition to the known naked singularity as the momentum flow to mass ratio increases. Interestingly, there does not exist new zero momentum solution in these cases.
Quantization of Minimal Strings: a Mechanical Analog
Gomez, Cesar; Montanez, Sergio; Resco, Pedro [Instituto de Fisica Teorica CSIC/UAM, C-XVI Universidad Autonoma, E-28049 Madrid (Spain)
2006-06-19
Recent progress in the study of Liouville field theory opens the possibility to address some problems of quantum gravity using minimal strings as a theoretical laboratory. We present a procedure to embed the minimal string target space into the phase space of an associated mechanical system. By this map quantum effects on the target space correspond to quantum corrections on the mechanical model.
Stability of AdS black strings
T. Delsate
2008-08-14
We review the recent developements in the stability problem and phase diagram for asymptotically locally $AdS$ black strings. First, we quickly review the case of locally flat black string before turning to the case of locally $AdS$ spacetimes.
Melt dumping in string stabilized ribbon growth
Sachs, Emanuel M. (42 Old Middlesex Rd., Belmont, MA 02178)
1986-12-09
A method and apparatus for stabilizing the edge positions of a ribbon drawn from a melt includes the use of wettable strings drawn in parallel up through the melt surface, the ribbon being grown between the strings. A furnace and various features of the crucible used therein permit continuous automatic growth of flat ribbons without close temperature control or the need for visual inspection.
String Gas Cosmology and Non-Gaussianities
Bin Chen; Yi Wang; Wei Xue; Robert Brandenberger
2008-03-05
Recently it has been shown that string gas cosmology, an alternative model of the very early universe which does not involve a period of cosmological inflation, can give rise to an almost scale invariant spectrum of metric perturbations. Here we calculate the non-Gaussianities of the spectrum of cosmological fluctuations in string gas cosmology, and find that these non-Gaussianities depend linearly on the wave number and that their amplitude depends sensitively on the string scale. If the string scale is at the TeV scale, string gas cosmology could lead to observable non-Gaussianities, if it is close to the Planck scale, then the non-Gaussianities on current cosmological scales are negligible.
Electric Magnetic Duality in String Theory
Ashoke Sen
1992-10-06
The electric-magnetic duality transformation in four dimensional heterotic string theory discussed by Shapere, Trivedi and Wilczek is shown to be an exact symmetry of the equations of motion of low energy effective field theory even after including the scalar and the vector fields, arising due to compactification, in the effective field theory. Using this duality transformation we construct rotating black hole solutions in the effective field theory carrying both, electric and magnetic charges. The spectrum of extremal magnetically charged black holes turns out to be similar to that of electrically charged elementary string excitations. We also discuss the possibility that the duality symmetry is an exact symmetry of the full string theory under which electrically charged elementary string excitations get exchanged with magnetically charged soliton like solutions. This proposal might be made concrete following the suggestion of Dabholkar et. al. that fundamental strings may be regarded as soliton like classical solutions in the effective field theory.
Wiggly cosmic strings accrete dark energy
Pedro F. Gonzalez-Diaz; Jose A. Jimenez Madrid
2005-06-29
This paper deals with a study of the cylindrically symmetric accretion of dark energy with equation of state $p=w\\rho$ onto wiggly straight cosmic strings. We have obtained that when $w>-1$ the linear energy density in the string core gradually increases tending to a finite maximum value as time increases for all considered dark energy models. On the regime where the dominant energy condition is violated all such models predict a steady decreasing of the linear energy density of the cosmic strings as phantom energy is being accreted. The final state of the string after such an accretion process is a wiggleless defect. It is argued however that if accreation of phantom energy would proceed by successive quantum steps then the defect would continue losing linear energy density until a minimum nonzero value which can be quite smaller than that corresponding to the unperturbed string.
Ishii, Takaaki
2015-01-01
We study nonlinear dynamics of the flux tube between an external quark-antiquark pair in $\\mathcal{N}=4$ super Yang-Mills theory using the AdS/CFT duality. In the gravity side, the flux tube is realized by a fundamental string whose endpoints are attached to the AdS boundary. We perturb the endpoints in various ways and numerically compute the time evolution of the nonlinearly oscillating string. As a result, cusps can form on the string, accompanied by weak turbulence and power law behavior in the energy spectrum. When cusps traveling on the string reach the boundary, we observe the divergence of the force between the quark and antiquark. Minimal amplitude of the perturbation below which cusps do not form is also investigated. No cusp formation is found when the string moves in all four AdS space directions, and in this case an inverse energy cascade follows a direct cascade.
Takaaki Ishii; Keiju Murata
2015-06-25
We study nonlinear dynamics of the flux tube between an external quark-antiquark pair in $\\mathcal{N}=4$ super Yang-Mills theory using the AdS/CFT duality. In the gravity side, the flux tube is realized by a fundamental string whose endpoints are attached to the AdS boundary. We perturb the endpoints in various ways and numerically compute the time evolution of the nonlinearly oscillating string. As a result, cusps can form on the string, accompanied by weak turbulence and power law behavior in the energy spectrum. When cusps traveling on the string reach the boundary, we observe the divergence of the force between the quark and antiquark. Minimal amplitude of the perturbation below which cusps do not form is also investigated. No cusp formation is found when the string moves in all four AdS space directions, and in this case an inverse energy cascade follows a direct cascade.
Microscopic unitary description of tidal excitations in high-energy string-brane collisions
Giuseppe D'Appollonio; Paolo Di Vecchia; Rodolfo Russo; Gabriele Veneziano
2013-11-15
The eikonal operator was originally introduced to describe the effect of tidal excitations on higher-genus elastic string amplitudes at high energy. In this paper we provide a precise interpretation for this operator through the explicit tree-level calculation of generic inelastic transitions between closed strings as they scatter off a stack of parallel Dp-branes. We perform this analysis both in the light-cone gauge, using the Green-Schwarz vertex, and in the covariant formalism, using the Reggeon vertex operator. We also present a detailed discussion of the high energy behaviour of the covariant string amplitudes, showing how to take into account the energy factors that enhance the contribution of the longitudinally polarized massive states in a simple way.
Microscopic unitary description of tidal excitations in high-energy string-brane collisions
D'Appollonio, Giuseppe; Vecchia, Paolo; Veneziano, Gabriele
2013-01-01
The eikonal operator was originally introduced to describe the effect of tidal excitations on higher-genus elastic string amplitudes at high energy. In this paper we provide a precise interpretation for this operator through the explicit tree-level calculation of generic inelastic transitions between closed strings as they scatter off a stack of parallel Dp-branes. We perform this analysis both in the light-cone gauge, using the Green-Schwarz vertex, and in the covariant formalism, using the Reggeon vertex operator. We also present a detailed discussion of the high energy behaviour of the covariant string amplitudes, showing how to take into account the energy factors that enhance the contribution of the longitudinally polarized massive states in a simple way.
Proton stability in grand unified theories, in strings, and in branes
Pran Nath; Pavel Fileviez Perez
2007-04-23
A broad overview of the current status of proton stability in unified models of particle interactions is given which includes non - supersymmetric unification, SUSY and SUGRA unified models, unification based on extra dimensions, and string-M-theory models. The extra dimensional unification includes 5D and 6D and universal extra dimensional (UED) models, and models based on warped geometry. Proton stability in a wide array of string theory and M theory models is reviewed. These include Calabi-Yau models, grand unified models with Kac-Moody levels $k>1$, a new class of heterotic string models, models based on intersecting D branes, and string landscape models. The destabilizing effect of quantum gravity on the proton is discussed. The possibility of testing grand unified models, models based on extra dimensions and string-M-theory models via their distinctive modes is investigated. The proposed next generation proton decay experiments, HyperK, UNO, MEMPHYS, ICARUS, LANNDD (DUSEL), and LENA would shed significant light on the nature of unification complementary to the physics at the LHC. Mathematical tools for the computation of proton lifetime are given in the appendices. Prospects for the future are discussed.
CLNS00/1710 STRING WEBS AND THE DECAY OF
CLNS00/1710 STRING WEBS AND THE DECAY OF SUPERSYMMETRIC PARTICLES PHILIP C. ARGYRES and K. NARAYAN is a generalization of the ``string web'' picture of these states found in string constructions of certain theories coincides with the ``string web'' picture of BPS states developed in the context of the D3brane
Effects of overlapping strings in pp collisions
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Bierlich, Christian [Lund University; Gustafson, Gösta [Lund University; Lönnblad, Leif [Lund University; Tarasov, Andrey [JLAB
2015-03-01
In models for hadron collisions based on string hadronization, the strings are usually treated as independent, allowing no interaction between the confined colour fields. In studies of nucleus collisions it has been suggested that strings close in space can fuse to form "colour ropes." Such ropes are expected to give more strange particles and baryons, which also has been suggested as a signal for plasma formation. Overlapping strings can also be expected in pp collisions, where usually no phase transition is expected. In particular at the high LHC energies the expected density of strings is quite high. To investigate possible effects of rope formation, we present a model in which strings are allowed to combine into higher multiplets, giving rise to increased production of baryons and strangeness, or recombine into singlet structures and vanish. Also a crude model for strings recombining into junction structures is considered, again giving rise to increased baryon production. The models are implemented in the DIPSY MC event generator, using PYTHIA8 for hadronization, and comparison to pp minimum bias data, reveals improvement in the description of identified particle spectra.
Effects of overlapping strings in pp collisions
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Bierlich, Christian; Gustafson, Gösta; Lönnblad, Leif; Tarasov, Andrey
2015-03-26
In models for hadron collisions based on string hadronization, the strings are usually treated as independent, allowing no interaction between the confined colour fields. In studies of nucleus collisions it has been suggested that strings close in space can fuse to form "colour ropes." Such ropes are expected to give more strange particles and baryons, which also has been suggested as a signal for plasma formation. Overlapping strings can also be expected in pp collisions, where usually no phase transition is expected. In particular at the high LHC energies the expected density of strings is quite high. To investigate possiblemore »effects of rope formation, we present a model in which strings are allowed to combine into higher multiplets, giving rise to increased production of baryons and strangeness, or recombine into singlet structures and vanish. Also a crude model for strings recombining into junction structures is considered, again giving rise to increased baryon production. The models are implemented in the DIPSY MC event generator, using PYTHIA8 for hadronization, and comparison to pp minimum bias data, reveals improvement in the description of identified particle spectra.« less
Strings and their compactification from the particle viewpoint
Slansky, R.
1986-01-01
A series of four lectures is given which deals with the particle formulation of string theory. An introductory lecture is given on where the idea of strings comes from and what strings are. An introduction is given to simple Lie algebras and their representations. Compactified strings and the heterotic theories are discussed, showing how infinite-dimensional Kac-Moody affine algebras can be spectrum generating algebras in (open) string theories. The spectrum of excited states of the heterotic string is examined, and comments are made on representations of affine algebras. Some aspects are shown of the algebraic structure of compactified closed bosonic strings. (LEW)
SU(4) pure-gauge string tensions
Shigemi Ohta; Matthew Wingate
1998-08-19
In response to recently renewed interests in SU(N) pure-gauge dynamics with large N, both from M/string duality and from finite-temperature QCD phase structure, we calculate string tensions acting between the fundamental 4, diquark 6 and other color charges in SU(4) pure-gauge theory at temperatures below the deconfining phase change and above the bulk phase transition. Our results suggest 4 and 6 representations have different string tensions, with a ratio of about 1.3. We also found the deconfining phase change is not strong.
Cosmological String Backgrounds from Gauged WZW Models
C. Kounnas; D. Luest
1992-05-18
We discuss the four-dimensional target-space interpretation of bosonic strings based on gauged WZW models, in particular of those based on the non-compact coset space $SL(2,{\\bf R})\\times SO(1,1)^2 /SO(1,1)$. We show that these theories lead, apart from the recently broadly discussed black-hole type of backgrounds, to cosmological string backgrounds, such as an expanding Universe. Which of the two cases is realized depends on the sign of the level of the corresponding Kac-Moody algebra. We discuss various aspects of these new cosmological string backgrounds.
Energy density bounds for black strings
Shinya Tomizawa
2005-06-07
The conserved charge called Y-ADM mass density associated with asymptotically translational Killing-Yano tensor gives us an appropriate physical meaning about the energy density of $p$ brane spacetimes or black strings. We investigated the positivity of energy density in black string spacetimes, using the spinorial technique introduced by Witten. Recently, the positivity of Y-ADM mass density in p brane spacetimes was discussed. In this paper, we will extend this discussion to the transversely asymptotically flat black string spacetimes containing an apparent horizon. We will give the sufficient conditions for the Y-ADM mass density to become positive in such spacetimes.
Charged rotating dilaton black strings
Dehghani, M.H.; Farhangkhah, N.
2005-02-15
In this paper we, first, present a class of charged rotating solutions in four-dimensional Einstein-Maxwell-dilaton gravity with zero and Liouville-type potentials. We find that these solutions can present a black hole/string with two regular horizons, an extreme black hole or a naked singularity provided the parameters of the solutions are chosen suitable. We also compute the conserved and thermodynamic quantities, and show that they satisfy the first law of thermodynamics. Second, we obtain the (n+1)-dimensional rotating solutions in Einstein-dilaton gravity with Liouville-type potential. We find that these solutions can present black branes, naked singularities or spacetimes with cosmological horizon if one chooses the parameters of the solutions correctly. Again, we find that the thermodynamic quantities of these solutions satisfy the first law of thermodynamics.
A. Klemm; R. Schimmrigk
1992-04-20
We investigate a class of (2,2) supersymmetric string vacua which may be represented as Landau--Ginzburg theories with a quasihomogeneous potential which has an isolated singularity at the origin. There are at least three thousand distinct models in this class. All vacua of this type lead to Euler numbers which lie in the range $-960 \\leq \\chi \\leq 960$. The Euler characteristics do not pair up completely hence the space of Landau--Ginzburg ground states is not mirror symmetric even though it exhibits a high degree of symmetry. We discuss in some detail the relation between Landau--Ginzburg models and Calabi--Yau manifolds and describe a subtlety regarding Landau--Ginzburg potentials with an arbitrary number of fields. We also show that the use of topological identities makes it possible to relate Landau-Ginzburg theories to types of Calabi-Yau manifolds for which the usual Landau-Ginzburg framework does not apply.
Review on High energy String Scattering Amplitudes and Symmetries of String Theory
Lee, Jen-Chi
2015-01-01
We review high energy symmetries of string theory at both the fixed angle or Gross regime (GR) and the fixed momentum transfer or Regge regime (RR). We calculated in details high energy string scattering amplitudes at arbitrary mass levels for both regimes. We discovered infinite linear relations among fixed angle string amplitudes conjectured by Gross in 1988 from decoupling of high energy zero-norm states (ZNS), and infinite recurrence relations among Regge string amplitudes from Kummer function U and Appell function F. In the GR/RR regime, all high energy string amplitudes can be solved by these linear/recurrence relations so that all GR/RR string amplitudes can be expressed in terms of one single GR/RR string amplitude. In addition, we found an interesting link between string amplitudes of the two regimes, and discovered that at each mass level the ratios among fixed angle amplitudes can be extracted from Regge string scattering amplitudes. This result enables us to argue that the known SL(5,C) dynamical ...
The pomeron in closed bosonic string theory
Fazio, A. R.
2010-12-22
We compute the couplings of the pomeron to the first few mass levels of closed bosonic string states in flat space. We recognize the deviation from the linearity of the Regge trajectories in a five dimensional anti De Sitter background.
Smart Lighting Controller!! Smart lighting!
Anderson, Betty Lise
'll build the circuit! We'll use an LED to represent the room lights! #12;4! Block diagram! Battery! Rail! #12;23! LED: light-emitting diode! Diode conducts current in only one direction! When current flows1! Smart Lighting Controller!! #12;2! Smart lighting! No need to spend energy lighting the room if
String Junctions and Holographic Interfaces
Marco Chiodaroli; Michael Gutperle; Ling-Yan Hung; Darya Krym
2010-11-22
In this paper we study half-BPS type IIB supergravity solutions with multiple $AdS_3\\times S^3\\times M_4$ asymptotic regions, where $M_4$ is either $T^4$ or $K_3$. These solutions were first constructed in [1] and have geometries given by the warped product of $AdS_2 \\times S^2 \\times M_4 $ over $\\Sigma$, where $\\Sigma$ is a Riemann surface. We show that the holographic boundary has the structure of a star graph, i.e. $n$ half-lines joined at a point. The attractor mechanism and the relation of the solutions to junctions of self-dual strings in six-dimensional supergravity are discussed. The solutions of [1] are constructed introducing two meromorphic and two harmonic functions defined on $\\Sigma$. We focus our analysis on solutions corresponding to junctions of three different conformal field theories and show that the conditions for having a solution charged only under Ramond-Ramond three-form fields reduce to relations involving the positions of the poles and the residues of the relevant harmonic and meromorphic functions. The degeneration limit in which some of the poles collide is analyzed in detail. Finally, we calculate the holographic boundary entropy for a junction of three CFTs and obtain a simple expression in terms of poles and residues.
Charged String-like Solutions of Low-energy Heterotic String Theory
Daniel Waldram
1992-10-06
Two string-like solutions to the equations of motion of the low-energy effective action for the heterotic string are found, each a source of electric and magnetic fields. The first carries an electric current equal to the electric charge per unit length and is the most general solution which preserves one half of the supersymmetries. The second is the most general charged solution with an event horizon, a `black string'. The relationship of the solutions to fundamental, macroscopic heterotic strings is discussed, and in particular it is shown that any stable state of such a fundamental string also preserves one half of the supersymmetries, in the same manner as the first solution.
Low energy 2+1 string gravity; black hole solutions
A. A. Garcia Diaz; G. Gutierrez Cano
2014-12-17
In this report a detailed derivation of the dynamical equations for an n dimensional heterotic string theory of the Horowitz type is carried out in the string frame and in the Einstein frame too. In particular, the dynamical equations of the three dimensional string theory are explicitly given. The relation of the Horowitz Welch and Horne Horowitz string black hole solution is exhibited. The Chan Mann charged dilaton solution is derived and the subclass of string solutions field is explicitly identified. The stationary generalization, via SL(2;R) transformations, of the static (2+1) Horne Horowitz string black hole solution is given.
Mines 2009 Fall Academic July 2008 S M T W T F S 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 August 2008 S M T W T F S 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 September 2008 S M T W T F S 1 2 3 4 5 6 7 8 9 10 11 12 13 14
Perturbative String Thermodynamics near Black Hole Horizons
Thomas G. Mertens; Henri Verschelde; Valentin I. Zakharov
2015-07-01
We provide further computations and ideas to the problem of near-Hagedorn string thermodynamics near (uncharged) black hole horizons, building upon our earlier work JHEP 1403 (2014) 086. The relevance of long strings to one-loop black hole thermodynamics is emphasized. We then provide an argument in favor of the absence of $\\alpha'$-corrections for the (quadratic) heterotic thermal scalar action in Rindler space. We also compute the large $k$ limit of the cigar orbifold partition functions (for both bosonic and type II superstrings) which allows a better comparison between the flat cones and the cigar cones. A discussion is made on the general McClain-Roth-O'Brien-Tan theorem and on the fact that different torus embeddings lead to different aspects of string thermodynamics. The black hole/string correspondence principle for the 2d black hole is discussed in terms of the thermal scalar. Finally, we present an argument to deal with arbitrary higher genus partition functions, suggesting the breakdown of string perturbation theory (in $g_s$) to compute thermodynamical quantities in black hole spacetimes.
String Theory and Math: Why This Marriage May Last
Aganagic, Mina
2015-01-01
String theory is changing the relationship between mathematics and physics. The central role is played by the phenomenon of duality, which is intrinsic to quantum physics and abundant in string theory.
Angenent, Lars T.
-making stories such as New York banning fracking; the California drought; and holiday favorites, including kind to appear in the state. Christian Science Monitor:"New York State MovesTo Ban Fracking" 12 fracturing,or fracking. The Hill:"Winning theWar on Fossil Fuels" 12.09.2014 Charles Greene
Coiled tubing velocity strings keep wells unloaded
Wesson, H.R.; Shursen, J.L.
1989-07-01
Liquid loading is a problem in many older and even some newer gas wells, particularly in pressure depletion type reservoirs. This liquid loading results in decreased production and may even kill the well. The use of coiled tubing as a velocity string (or siphon string) has proved to be an economically viable alternative to allow continued and thus, increased cumulative production for wells experiencing liquid loading problems. Coiled tubing run inside the existing production string reduces the flow area, whether the well is produced up the tubing or up the annulus. This reduction in flow area results in an increase in flow velocity and thus, an increase in the well's ability to unload fluids.
On the solutions to the string equation
A. Schwarz
1991-09-10
The set of solutions to the string equation $[P,Q]=1$ where $P$ and $Q$ are differential operators is described.It is shown that there exists one-to-one correspondence between this set and the set of pairs of commuting differential operators.This fact permits us to describe the set of solutions to the string equation in terms of moduli spa- ces of algebraic curves,however the direct description is much simpler. Some results are obtained for the superanalog to the string equation where $P$ and $Q$ are considered as superdifferential operators. It is proved that this equation is invariant with respect to Manin-Radul, Mulase-Rabin and Kac-van de Leur KP-hierarchies.
DIRECTIONAL PROPAGATION CANCELLATION FOR ACOUSTIC COMMUNICATION ALONG THE DRILL STRING
DIRECTIONAL PROPAGATION CANCELLATION FOR ACOUSTIC COMMUNICATION ALONG THE DRILL STRING Sinan along the drill string to the surface. Normal drilling operations produce in-band acoustic noise at intensities comparable to the transducer output while lossy propagation through the drill string and surface
The Early Years of String Theory: A Personal Perspective
John H. Schwarz
2009-04-03
This article surveys some of the highlights in the development of string theory through the first superstring revolution in 1984. The emphasis is on topics in which the author was involved, especially the observation that critical string theories provide consistent quantum theories of gravity and the proposal to use string theory to construct a unified theory of all fundamental particles and forces.
Thermodynamic fluctuation in black string flow
Meng Sun; Yong-Chang Huna
2015-06-14
It has long been noticed that Laudau-Lifshitz theory can be used to study the fluctuation of a system that contains a black hole. Since the black string can be constructed by extending n-dimensional black hole into one extra dimension. We study the fluctuation of black string flow with a Schwarzschlid-like metric in D=n+1 dimensional spacetime and a charged solution in D=5 dimensional spacetime and get the second moments of the fluctuation of the mass flux and charge flux.
Thermodynamic fluctuation in black string flow
Meng Sun; Yong-Chang Huang
2015-05-11
It has long been noticed that Laudau-Lifshitz theory can be used to study the fluctuation of a system that contains a black hole. Since the black string can be constructed by extending n-dimensional black hole into one extra dimension. We study the fluctuation of black string flow with a Schwarzschlid-like metric in D=n+1 dimensional spacetime and a charged solution in D=5 dimensional spacetime and get the second moments of the fluctuation of the mass flux and charge flux.
de Sitter String Vacua from Kahler Uplifting
Alexander Westphal
2007-06-22
We present a new way to construct de Sitter vacua in type IIB flux compactifications, in which the interplay of the leading perturbative and non-perturbative effects stabilize all moduli in dS vacua at parametrically large volume. Here, the closed string fluxes fix the dilaton and the complex structure moduli while the universal leading perturbative quantum correction to the Kahler potential together with non-perturbative effects stabilize the volume Kahler modulus in a dS_4-vacuum. Since the quantum correction is known exactly and can be kept parametrically small, this construction leads to calculable and explicitly realized de Sitter vacua of string theory with spontaneously broken supersymmetry.
Diffractive Scattering and Gauge/String Duality
Tan, Chung-I [Brown University, Providence, Rhode Island, United States
2009-09-01
High-energy diffractive scattering will be discussed based on Gauge/String duality. As shown by Brower, Polchinski, Strassler and Tan, the ubiquitous Pomeron emerges naturally in gauge theories with string-theoretical descriptions. Its existence is intimately tied to gluons, and also to the energy-momentum tensor. With a confining dual background metric, the Pomeron can be interpreted as a 'massive graviton'. In a single unified step, both its infrared and ultraviolet properties are dealt with, reflecting confinement and conformal symmetry respectively. An effective field theory for high-energy scattering can be constructed. Applications based on this approach will also be described.
Closed strings from decaying D-branes
Neil Lambert; Hong Liu; Juan Maldacena
2007-02-05
We compute the emission of closed string radiation from homogeneous rolling tachyons. For an unstable decaying D$p$-brane the radiated energy is infinite to leading order for $p\\leq 2$ and finite for $p>2$. The closed string state produced by a decaying brane is closely related to the state produced by D-instantons at a critical Euclidean distance from $t=0$. In the case of a D0 brane one can cutoff this divergence so that we get a finite energy final state which would be the state that the brane decays into.
Cosmic strings: A problem or a solution
Bennett, D.P.; Bouchet, F.R.
1987-10-01
The most fundamental issue in the theory of cosmic strings is addressed by means of Numerical Simulations: the existence of a scaling solution. The resolution of this question will determine whether cosmic strings can form the basis of an attractive theory of galaxy formation or prove to be a cosmological disaster like magnetic monopoles or domain walls. After a brief discussion of our numerical technique, results are presented which, though still preliminary, offer the best support to date of this scaling hypothesis. 6 refs., 2 figs.
Light Properties Light travels at the speed of light `c'
Mojzsis, Stephen J.
LIGHT!! #12;Light Properties Light travels at the speed of light `c' C = 3 x 108 m/s Or 190,000 miles/second!! Light could travel around the world about 8 times in one second #12;What is light?? Light is a "wave packet" A photon is a "light particle" #12;Electromagnetic Radiation and You Light is sometimes
United States. Bonneville Power Administration.
1985-04-01
The Fish and Wildlife Division of Bonneville Power Administration (BPA) hosted a meeting for contractors to present the results of fiscal year 1984 research conducted to implement the Northwest Power Planning Council's Fish and Wildlife Program. The meeting focused on those projects specifically related to natural and artificial propagation of salmonids. The presentations were held at the Holiday Inn Airport in Portland, Oregon, on March 27-29, 1985. This document contains abstracts of the presentations from that meeting. Section 1 contains abstracts on artificial propagation, fish health, and downstream migration, and Section 2 contains abstracts on natural propagation and habitat improvement. The abstracts are indexed by BPA Project Number and by Fish and Wildlife Program Measure. The registered attendees at the meeting are listed alphabetically in Appendix A and by affiliation in Appendix B.
Abelian-Higgs strings in Rastall gravity
Eugenio R. Bezerra de Mello; Julio C. Fabris; Betti Hartmann
2015-04-02
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.
Evidence for Non-perturbative String Symmetries
John H. Schwarz
1994-11-29
String theory appears to admit a group of discrete field transformations -- called $S$ dualities -- as exact non-perturbative quantum symmetries. Mathematically, they are rather analogous to the better-known $T$ duality symmetries, which hold perturbatively. In this talk the evidence for $S$ duality is reviewed and some speculations are presented.
P. S. Howe; N. D. Lambert; P. C. West
1997-09-09
We obtain a BPS soliton of the M theory fivebrane's equations of motion representing a supersymmetric self-dual string. The resulting solution is then dimensionally reduced and used to obtain 0-brane and (p-2)-brane solitons on D-p-branes.
An Alternative String Landscape Cosmology: Eliminating Bizarreness
Clavelli, Louis J.
An Alternative String Landscape Cosmology: Eliminating Bizarreness L. Clavelli and Gary R landscape models or whether there are scenarios in which it is avoided. If a viable alternative cosmology in mind that the alternative is not ruled out. In addition to being consistent with current observations
Ninety-One Years Going home, I glimpsed a tail light go out;
Jones, Rafe
Ninety-One Years Going home, I glimpsed a tail light go out; the rain spoke sparks from side-side wall, a single string of four o'clock light. After ninety-one years, my mother's father was a hero
Slifer, Karl
2014-05-22
The bright blue glow from nuclear reactors is Cerenkov light. Karl Slifer describes how nuclear physicists can use this phenomenon to study the nucleus of the atom.
Slifer, Karl
2013-06-13
The bright blue glow from nuclear reactors is Cerenkov light. Karl Slifer describes how nuclear physicists can use this phenomenon to study the nucleus of the atom.
Broader source: Energy.gov [DOE]
When undertaking a lighting renovation in a Federal building, daylighting is the primary renewable energy opportunity. Photovoltaics (PV) also present an excellent opportunity. While this guide...
Musical Acoustics Lab, C. Bertulani, 2012 PreLab 4 Standing Waves in a String
Bertulani, Carlos A. - Department of Physics and Astronomy, Texas A&M University
Standing Waves in a String Standing waves are set up in the strings of musical instruments when, a violin bow will excite a unique standing wave vibration of the string. The string's vibrations standing waves. Also standing waves only occur when the frequency of the vibration in the string allows
Walmart Sees the Light for Parking Lots
Office of Energy Efficiency and Renewable Energy (EERE)
I don't think about parking lots often. Hot in the summer and jammed with frantic shoppers during holidays, I try to spend as little time in them as possible. But because my passion is energy...
Strings, vortex rings, and modes of instability
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Gubser, Steven S.; Nayar, Revant; Parikh, Sarthak
2015-03-01
We treat string propagation and interaction in the presence of a background Neveu–Schwarz three-form field strength, suitable for describing vortex rings in a superfluid or low-viscosity normal fluid. A circular vortex ring exhibits instabilities which have been recognized for many years, but whose precise boundaries we determine for the first time analytically in the small core limit. Two circular vortices colliding head-on exhibit stronger instabilities which cause splitting into many small vortices at late times. We provide an approximate analytic treatment of these instabilities and show that the most unstable wavelength is parametrically larger than a dynamically generated length scalemore »which in many hydrodynamic systems is close to the cutoff. We also summarize how the string construction we discuss can be derived from the Gross–Pitaevskii Lagrangian, and also how it compares to the action for giant gravitons.« less
Open string amplitudes of closed topological vertex
Takasaki, Kanehisa
2015-01-01
The closed topological vertex is the simplest "off-strip" case of non-compact toric Calabi-Yau threefolds with acyclic web diagrams. By the diagrammatic method of topological vertex, open string amplitudes of topological string theory therein can be obtained by gluing a single topological vertex to an "on-strip" subdiagram of the tree-like web diagram. If non-trivial partitions are assigned to just two parallel external lines of the web diagram, the amplitudes can be calculated with the aid of techniques borrowed from the melting crystal models. These amplitudes are thereby expressed as matrix elements, modified by simple prefactors, of an operator product on the Fock space of 2D charged free fermions. This fermionic expression can be used to derive $q$-difference equations for generating functions of special subsets of the amplitudes. These $q$-difference equations may be interpreted as the defining equation of a quantum mirror curve.
Open string amplitudes of closed topological vertex
Kanehisa Takasaki; Toshio Nakatsu
2015-07-25
The closed topological vertex is the simplest "off-strip" case of non-compact toric Calabi-Yau threefolds with acyclic web diagrams. By the diagrammatic method of topological vertex, open string amplitudes of topological string theory therein can be obtained by gluing a single topological vertex to an "on-strip" subdiagram of the tree-like web diagram. If non-trivial partitions are assigned to just two parallel external lines of the web diagram, the amplitudes can be calculated with the aid of techniques borrowed from the melting crystal models. These amplitudes are thereby expressed as matrix elements, modified by simple prefactors, of an operator product on the Fock space of 2D charged free fermions. This fermionic expression can be used to derive $q$-difference equations for generating functions of special subsets of the amplitudes. These $q$-difference equations may be interpreted as the defining equation of a quantum mirror curve.
On Water, Steam and String Theory
Christof Schmidhuber
1997-01-22
This is a colloquium-style review lecture for physicists and non-physicists, as part of the requirements for ``Habilitation'' at the university of Bern: At a pressure of 220 atm. and a temperature of 374 Celsius there is a second-order phase transition between water and steam. Understanding it requires the concept of the renormalization group. Images from computer simulations of the lattice gas model (included) are used to explain its basic ideas. It is briefly reviewed how the renormalization group is used to compute critical coefficients for the water-steam phase transition, in good agreement with experiment. Applications in particle physics and string theory are mentioned. The appendix contains a sample of the author's results on renormalization group flows in theories with dynamical gravity and their relation to perturbative string theory: gravity modifies critical coefficients and phase diagrams, in agreement with numerical calculations, and leads to curious phenomena such as oscillating flows and quantum mechanical flows.
Signal connection for a downhole tool string
Hall, David R.; Hall, Jr., H. Tracy; Pixton, David S.; Bradford, Kline; Fox, Joe; Briscoe, Michael
2006-08-29
A signal transmission connection for a tool string used in exploration and production of natural resources, namely: oil, gas, and geothermal energy resources. The connection comprises first and second annular elements deployed in cooperative association with each other. The respective elements comprise inductive transducers that are capable of two-way signal transmission between each other, with downhole components of the tool string, and with ground-level equipment. The respective inductive transducers comprise one or more conductive loops housed within ferrite troughs, or within ferrite trough segments. When energized, the conductive loops produce a magnetic field suitable for transmitting the signal. The second element may be rotational in drilling applications. The respective elements may be fitted with electronic equipment to aid and manipulate the transmission of the signal. The first element may also be in communication with the World Wide Web.
Open string amplitudes of closed topological vertex
Kanehisa Takasaki; Toshio Nakatsu
2015-11-20
The closed topological vertex is the simplest ``off-strip'' case of non-compact toric Calabi-Yau threefolds with acyclic web diagrams. By the diagrammatic method of topological vertex, open string amplitudes of topological string theory therein can be obtained by gluing a single topological vertex to an ``on-strip'' subdiagram of the tree-like web diagram. If non-trivial partitions are assigned to just two parallel external lines of the web diagram, the amplitudes can be calculated with the aid of techniques borrowed from the melting crystal models. These amplitudes are thereby expressed as matrix elements, modified by simple prefactors, of an operator product on the Fock space of 2D charged free fermions. This fermionic expression can be used to derive $q$-difference equations for generating functions of special subsets of the amplitudes. These $q$-difference equations may be interpreted as the defining equation of a quantum mirror curve.
Obstacle to populating the string theory landscape
Johnson, Matthew C; Larfors, Magdalena
2008-12-15
We construct domain walls and instantons in a class of models with coupled scalar fields, determining, in agreement with previous studies, that many such solutions contain naked timelike singularities. Vacuum bubble solutions of this type do not contain a region of true vacuum, obstructing the ability of eternal inflation to populate other vacua. We determine a criterion that potentials must satisfy to avoid the existence of such singularities and show that many domain wall solutions in type IIB string theory are singular.
Non-perturbative String Theory from Water Waves
Ramakrishnan Iyer; Clifford V. Johnson; Jeffrey S. Pennington
2010-11-29
We use a combination of a 't Hooft limit and numerical methods to find non-perturbative solutions of exactly solvable string theories, showing that perturbative solutions in different asymptotic regimes are connected by smooth interpolating functions. Our earlier perturbative work showed that a large class of minimal string theories arise as special limits of a Painleve IV hierarchy of string equations that can be derived by a similarity reduction of the dispersive water wave hierarchy of differential equations. The hierarchy of string equations contains new perturbative solutions, some of which were conjectured to be the type IIA and IIB string theories coupled to (4,4k-2) superconformal minimal models of type (A,D). Our present paper shows that these new theories have smooth non-perturbative extensions. We also find evidence for putative new string theories that were not apparent in the perturbative analysis.
Long-range correlation studies at the SPS energies in MC model with string fusion
Vladimir Kovalenko; Vladimir Vechernin
2015-02-05
Studies of the ultrarelativistic collisions of hadrons and nuclei at different centrality and energy enable to explore the QCD phase diagram in a wide range of temperature and baryon density. Long-range correlation studies are considered as a tool, sensitive to the observation of phase transition and the critical point. In the present work, a Monte Carlo model of proton-proton, proton-nucleus, and nucleus-nucleus collisions is applied to heavy and light ion collisions at the cms energy range from a few up to several hundred GeV per nucleon. The model describes the nuclear collisions at the partonic level through interaction of color dipoles and takes into account the effects of string fusion, which can be considered as an alternative to relativistic hydrodynamics way of describing the collective phenomena in heavy-ion collisions. The implementing of both the string fusion and the finite rapidity length of strings allowed to consider the particle production at non-zero baryochemical potential. We calculated the long-range correlation functions and correlation coefficients between multiplicities and transverse momentum at several energies for different colliding systems and obtained predictions for the experiment.
Long-range correlation studies at the SPS energies in MC model with string fusion
Kovalenko, Vladimir
2015-01-01
Studies of the ultrarelativistic collisions of hadrons and nuclei at different centrality and energy enable to explore the QCD phase diagram in a wide range of temperature and baryon density. Long-range correlation studies are considered as a tool, sensitive to the observation of phase transition and the critical point. In the present work, a Monte Carlo model of proton-proton, proton-nucleus, and nucleus-nucleus collisions is applied to heavy and light ion collisions at the cms energy range from a few up to several hundred GeV per nucleon. The model describes the nuclear collisions at the partonic level through interaction of color dipoles and takes into account the effects of string fusion, which can be considered as an alternative to relativistic hydrodynamics way of describing the collective phenomena in heavy-ion collisions. The implementing of both the string fusion and the finite rapidity length of strings allowed to consider the particle production at non-zero baryochemical potential. We calculated th...
Semiclassical strings in AdS(3) X S^2
Bogeun Gwak; Bum-Hoon Lee; Kamal L. Panigrahi; Chanyong Park
2009-01-30
In this paper, we investigate the semiclassical strings in AdS(3)XS^2, in which the string configuration of AdS(3) is classified to three cases depending on the parameters. Each of these has a different anomalous dimension proportional to logS, S^(1/3) and S, where S is a angular momentum on AdS(3). Further we generalize the dispersion relations for various string configuration on AdS(3)XS^2.
Gravitational Collapse of Null Radiation and a String fluid
K S Govinder; M Govender
2003-04-03
We consider the end state of collapsing null radiation with a string fluid. It is shown that, if diffusive transport is assumed for the string, that a naked singularity can form (at least locally). The model has the advantage of not being asymptotically flat. We also analyse the case of a radiation-string two-fluid and show that a locally naked singularity can result in the collapse of such matter. We contrast this model with that of strange quark matter.
Open String Theory in 1+1 Dimensions
M. Bershadsky; D. Kutasov
1991-10-14
We show that tree level open two dimensional string theory is exactly solvable; the solution exhibits some unusual features, and is qualitatively different from the closed case. The open string ``tachyon'' S -- matrix describes free fermions, which can be interpreted as the quarks at the ends of the string. These ``quarks'' live naturally on a lattice in space-time. We also find an exact vacuum solution of the theory, corresponding to a charged black hole.
A casing string model for the personal computer
Zuniga-Pflucker, Manuel Pablo
1988-01-01
is often inaccurate - too conservative for shallow strings, too liberal for deep strings. Most wells, probably 90 percent of them, are designed . using uniaxial and biaxial techniques that rely heavily on safety factors to ensure adequate designs. While... uniaxial or biaxial conditions rather than triaxial and the uncertainty of the assumed worst conditions, conventional casing design relies heavily on safety factors to ensure an adequate design. When designing or analyzing a casing string...
N. Seiberg; L. Susskind; N. Toumbas
2000-05-04
Searching for space/time noncommutativity we reconsider open strings in a constant background electric field. The main difference between this situation and its magnetic counterpart is that here there is a critical electric field beyond which the theory does not make sense. We show that this critical field prevents us from finding a limit in which the theory becomes a field theory on a noncommutative spacetime. However, an appropriate limit toward the critical field leads to a novel noncritical string theory on a noncommutative spacetime.
The Hubble Web: The Dark Matter Problem and Cosmic Strings
Stephon Alexander
2007-02-27
I propose a reinterpretation of cosmic dark matter in which a rigid network of cosmic strings formed at the end of inflation. The cosmic strings fulfill three functions: At recombination they provide an accretion mechanism for virializing baryonic and warm dark matter into disks. These cosmic strings survive as configurations which thread spiral and elliptical galaxies leading to the observed flatness of rotation curves and the Tully-Fisher relation. We find a relationship between the rotational velocity of the galaxy and the string tension and discuss the testability of this model.
The Hubble Web: The Dark Matter Problem and Cosmic Strings
Alexander, Stephon
2009-07-06
I propose a reinterpretation of cosmic dark matter in which a rigid network of cosmic strings formed at the end of inflation. The cosmic strings fulfill three functions: At recombination they provide an accretion mechanism for virializing baryonic and warm dark matter into disks. These cosmic strings survive as configurations which thread spiral and elliptical galaxies leading to the observed flatness of rotation curves and the Tully-Fisher relation. We find a relationship between the rotational velocity of the galaxy and the string tension and discuss the testability of this model.
String Loop Corrections to Stable Non-BPS Branes
N. D. Lambert; I. Sachs
2000-10-31
We calculate the string loop corrections to the tachyon potential for stable non-BPS Dp-branes on the orbifold T^4/Z_2. We find a non-trivial phase structure and we show that, after tachyon condensation, the non-BPS Dp-branes are attracted to each other for p=0,1,2. We then identify the corresponding closed string boundary states together with the massless long range fields they excite. For p=3,4 the string loop correction diverge. We identify the massless closed string fields responsible for these divergencies and regularise the partition function using a Fischler-Susskind mechanism.
From Decay to Complete Breaking: Pulling the Strings in SU(2) Yang-Mills Theory
Pepe, M.; Wiese, U.-J.
2009-05-15
We study (2Q+1) strings connecting two static charges Q in (2+1)D SU(2) Yang-Mills theory. While the fundamental (2) string between two charges Q=(1/2) is unbreakable, the adjoint (3) string connecting two charges Q=1 can break. When a (4) string is stretched beyond a critical length, it decays into a (2) string by gluon pair creation. When a (5) string is stretched, it first decays into a (3) string, which eventually breaks completely. The energy of the screened charges at the ends of a string is well described by a phenomenological constituent gluon model.
CMB ISW-lensing bispectrum from cosmic strings
Yamauchi, Daisuke; Sendouda, Yuuiti; Takahashi, Keitaro E-mail: sendouda@cc.hirosaki-u.ac.jp
2014-02-01
We study the effect of weak lensing by cosmic (super-)strings on the higher-order statistics of the cosmic microwave background (CMB). A cosmic string segment is expected to cause weak lensing as well as an integrated Sachs-Wolfe (ISW) effect, the so-called Gott-Kaiser-Stebbins (GKS) effect, to the CMB temperature fluctuation, which are thus naturally cross-correlated. We point out that, in the presence of such a correlation, yet another kind of the post-recombination CMB temperature bispectra, the ISW-lensing bispectra, will arise in the form of products of the auto- and cross-power spectra. We first present an analytic method to calculate the autocorrelation of the temperature fluctuations induced by the strings, and the cross-correlation between the temperature fluctuation and the lensing potential both due to the string network. In our formulation, the evolution of the string network is assumed to be characterized by the simple analytic model, the velocity-dependent one scale model, and the intercommutation probability is properly incorporated in order to characterize the possible superstringy nature. Furthermore, the obtained power spectra are dominated by the Poisson-distributed string segments, whose correlations are assumed to satisfy the simple relations. We then estimate the signal-to-noise ratios of the string-induced ISW-lensing bispectra and discuss the detectability of such CMB signals from the cosmic string network. It is found that in the case of the smaller string tension, G? << 10{sup -7}, the ISW-lensing bispectrum induced by a cosmic string network can constrain the string-model parameters even more tightly than the purely GKS-induced bispectrum in the ongoing and future CMB observations on small scales.
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
by your library lights E Kilowatt-hours consumed by your library lights F Annual cost of operating your library lights H Current lighting index for your library ...
Mesons: Relativistic Bound States with String Tension
Anishetty, R; Anishetty, Ramesh; Kudtarkar, Santosh Kumar
2003-01-01
A systematic method of analysing Bethe-Salpeter equation using spectral representation for the relativistic bound state wave function is given. This has been explicitly applied in the context of perturbative QCD with string tension in the $1 \\over N$ expansion. We show that there are only a few stable bound state mesons due to the small "threshold mass"(constituent mass) of quarks. The asymptotic properties of the bound states are analytically analysed. The spectrum is derived analytically and compared phenomenologically. Chiral symmetry breaking and PCAC results are demonstrated. We make a simple minded observation to determine the size of the bound states as a function of the energy of the boundstate.
Higher-Spin Geometry and String Theory
D. Francia; A. Sagnotti
2006-02-14
The theory of freely-propagating massless higher spins is usually formulated via gauge fields and parameters subject to trace constraints. We summarize a proposal allowing to forego them by introducing only a pair of additional fields in the Lagrangians. In this setting, external currents satisfy usual Noether-like conservation laws, the field equations can be nicely related to those emerging from Open String Field Theory in the low-tension limit, and if the additional fields are eliminated without reintroducing the constraints a geometric, non-local description of the theory manifests itself.
Comment about UV regularization of basic commutators in string theories
A. Yu. Kamenshchik; I. M. Khalatnikov; M. Martellini
1998-06-24
Recently proposed by Hwang, Marnelius and Saltsidis zeta regularization of basic commutators in string theories is generalized to the string models with non-trivial vacuums. It is shown that implementation of this regularization implies the cancellation of dangerous terms in the commutators between Virasoro generators, which break Jacobi identity.
Computational Modeling of Chord Fingering for String Instruments
Radicioni, Daniele
Computational Modeling of Chord Fingering for String Instruments Daniele P. Radicioni (radicion for the fingering process with string instruments, based on a constraint satisfaction approach. The model is imple-mechanical aspects of the performer's hand in its interaction with the musical instrument. Introduction Music
RENEWAL THEORY IN ANALYSIS OF TRIES AND STRINGS: EXTENDED ABSTRACT
Janson, Svante
of this paper is to make propaganda for the use of renewal theory to study e.g. Markov models, even if we doRENEWAL THEORY IN ANALYSIS OF TRIES AND STRINGS: EXTENDED ABSTRACT SVANTE JANSON Abstract. We give a survey of a number of simple applications of renewal theory to problems on random strings, in particular
Dynamics of a self-gravitating thin cosmic string
B. Boisseau; C. Charmousis; B. Linet
1997-02-06
We assume that a self-gravitating thin string can be locally described by what we shall call a smoothed cone. If we impose a specific constraint on the model of the string, then its central line obeys the Nambu-Goto equations. If no constraint is added, then the worldsheet of the central line is a totally geodesic surface.
Character String Predicate Based Automatic Software Test Data Generation
Lyu, Michael R.
Character String Predicate Based Automatic Software Test Data Generation Ruilian Zhao Computer is an important element in programming. A problem that needs further research is how to automatically generate generation of program paths including character string predicates, and the effectiveness of this approach
SCHWARTZ TENNIS CENTER DAMPENERS, GRIPS, STRING, TENNIS BALLS
Pittendrigh, Barry
SCHWARTZ TENNIS CENTER DAMPENERS, GRIPS, STRING, TENNIS BALLS STRINGING:(We attempt to have all, Durability $34.00 Luxilon Big Banger Rough, Spin, Control, Durability $34.00 Prince Lightning, 16 g: $5.00 Wilson Pro Feel Plus Dampener: $4.00 TENNIS BALLS: Wilson US Open Tennis Balls: $3.25 SPECIAL
Quantum Fusion of Strings (Flux Tubes) and Domain Walls
S. Bolognesi; M. Shifman; M. B. Voloshin
2009-05-20
We consider formation of composite strings and domain walls as a result of fusion of two elementary objects (elementary strings in the first case and elementary walls in the second) located at a distance from each other. The tension of the composite object T_2 is assumed to be less than twice the tension of the elementary object T_1, so that bound states are possible. If in the initial state the distance d between the fusing strings or walls is much larger than their thickness and satisfies the conditions T_1 d^2 >> 1 (in the string case) and T_1 d^3 >> 1 (in the wall case), the problem can be fully solved quasiclassically. The fusion probability is determined by the first, "under the barrier" stage of the process. We find the bounce configuration and its extremal action S_B. In the wall problem e^{-S_B} gives the fusion probability per unit time per unit area. In the string case, due to a logarithmic infrared divergence, the problem is well formulated only for finite-length strings. The fusion probability per unit time can be found in the limit in which the string length is much larger than the distance between two merging strings.
RENEWAL THEORY IN ANALYSIS OF TRIES AND STRINGS: EXTENDED ABSTRACT
Janson, Svante
RENEWAL THEORY IN ANALYSIS OF TRIES AND STRINGS: EXTENDED ABSTRACT SVANTE JANSON Abstract. We give a survey of a number of simple applications of renewal theory to problems on random strings, in particular to tries and Khodak and Tunstall codes. 1. Introduction Although it long has been realized that renewal
The M Theory Five-Brane and the Heterotic String
John H. Schwarz
1997-05-13
Brane actions with chiral bosons present special challenges. Recent progress in the description of the two main examples -- the M theory five-brane and the heterotic string -- is described. Also, double dimensional reduction of the M theory five-brane on K3 is shown to give the heterotic string.
Peculiarities in the energy transfer by waves on strained strings
Butikov, Eugene
Peculiarities in the energy transfer by waves on strained strings Eugene I. Butikov St. Petersburg of elastic potential energy associated with waves in a stretched string is discussed. The influence of nonlinear coupling between transverse and longitudinal waves on the density of energy is investigated
Resonant acoustic transducer system for a well drilling string
Nardi, Anthony P. (Burlington, MA)
1981-01-01
For use in transmitting acoustic waves propated along a well drilling string, a piezoelectric transducer is provided operating in the relatively low loss acoustic propagation range of the well drilling string. The efficiently coupled transmitting transducer incorporates a mass-spring-piezoelectric transmitter combination permitting a resonant operation in the desired low frequency range.
Resonant acoustic transducer system for a well drilling string
Kent, William H. (Westford, MA); Mitchell, Peter G. (Concord, MA)
1981-01-01
For use in transmitting acoustic waves propagated along a well drilling string, a piezoelectric transducer is provided operating in the relatively low loss acoustic propagation range of the well drilling string. The efficiently coupled transmitting transducer incorporates a mass-spring-piezoelectric transmitter combination permitting resonant operation in the desired low frequency range.
ONE-DIRECTED INDECOMPOSABLE PURE INJECTIVE MODULES OVER STRING ALGEBRAS
Prest, Mike
ONE-DIRECTED INDECOMPOSABLE PURE INJECTIVE MODULES OVER STRING ALGEBRAS MIKE PREST (MANCHESTER) AND GENA PUNINSKI (LIMA) Abstract. We classify one-directed indecomposable pure injective modules over #12. In this paper we classify one-directed indecomposable pure injective modules over a string algebra A. We prove
Padgett, Miles [University of Glasgow, Glasgow, Scotland
2010-01-08
Optical vortices and orbital angular momentum are currently topical subjects in the optics literature. Although seemingly esoteric, they are, in fact, the generic state of light and arise whenever three or more plane waves interfere. To be observed by eye the light must be monochromatic. Laser speckle is one such example, where the optical energy circulates around each black spot, giving a local orbital angular momentum. This talk with report three on-going studies. First, when considering a volume of interfering waves, the laser specs map out threads of complete darkness embedded in the light. Do these threads form loops? Links? Or even knots? Second, when looking through a rapidly spinning window, the image of the world on the other side is rotated: true or false? Finally, the entanglement of orbital angular momentum states means measuring how the angular position of one photons sets the angular momentum of another: is this an angular version of the EPR (Einstein, Podolsky, and Rosen) paradox?
String stabilized ribbon growth a method for seeding same
Sachs, Emanuel M. (39 Harding Ave., Belmont, MA 02178)
1987-08-25
This invention is a method of initiating or seeding the growth of a crystalline or polycrystalline ribbon by the String Stabilized Ribbon Growth Method. The method for seeding the crystal growth comprises contacting a melt surface with a seed and two strings used in edge stabilization. The wetted strings attach to the wetted seed as a result of the freezing of the liquid melt. Upon drawing the seed, which is attached to the strings, away from the melt surface a melt liquid meniscus, a seed junction, and a growth interface forms. Further pulling of the attached seed causes a crystal ribbon to grow at the growth interface. The boundaries of the growing ribbon are: at the top the seed junction, at the bottom the freezing boundary of the melt liquid meniscus, and at the edges frozen-in strings.
Tachyon condensation in boundary string field theory at one loop
K. Bardakci; A. Konechny
2001-08-21
We compute the one-loop partition function for quadratic tachyon background in open string theory. Both closed and open string representations are developed. Using these representations we study the one-loop divergences in the partition function in the presence of the tachyon background. The divergences due to the open and closed string tachyons are treated by analytic continuation in the tachyon mass squared. We pay particular attention to the imaginary part of the analytically continued expressions. The last one gives the decay rate of the unstable vacuum. The dilaton tadpole is also given some partial consideration. The partition function is further used to study corrections to tachyon condensation processes describing brane descent relations. Assuming the boundary string field theory prescription for construction of the string field action via partition function holds at one loop level we study the one-loop corrections to the tachyon potential and to the tensions of lower-dimensional branes.
Holger B. Nielsen; Masao Ninomiya
2015-03-10
Bosonic string theory with the possibility for an arbitrary number of strings - i.e. a string ?eld theory - is formulated by a Hilbert space (a Fock space), which is just that for massless noninteracting scalars. We earlier presented this novel type of string ?eld theory, but now we show that it leads to scattering just given by the Veneziano model amplitude. Generalization to strings with fermion modes would presumably be rather easy. It is characteristic for our formulation /model that: 1) We have thrown away some null set of information compared to usual string ?eld theory, 2)Formulated in terms of our \\objects" (= the non-interacting scalars) there is no interaction and essentially no time development(Heisenberg picture), 3) so that the S-matrix is in our Hilbert space given as the unit matrix, S=1, and 4) the Veneziano scattering amplitude appear as the overlap between the initial and the ?nal state described in terms of the \\objects". 5) The integration in the Euler beta function making up the Veneziano model appear from the summation over the number of \\objects" from one of the incoming strings which goes into a certain one of the two outgoing strings. A correction from Weyl anomaly is needed to get the correct form of the Veneziano amplitude and it only fits for 26 dimensions.
Types of Lights Types of Lights
1 Types of Lights Types of Lights q So far we have studied point lights Radiate in all direc7ons q Other lights Direc7onal lights (posi7on-independent) Spotlights #12;2 Direc1onal Lights q Shine in a single, uniform direc7on q All rays
Gordon Chalmers
2006-10-13
A configuration of light pulses is generated, together with emitters and receptors, that allows computing. The computing is extraordinarily high in number of flops per second, exceeding the capability of a quantum computer for a given size and coherence region. The emitters and receptors are based on the quantum diode, which can emit and detect individual photons with high accuracy.
Parallel Dynamic Programming for Solving the String Editing Problem on a CGM/BSP
Dehene, Frank
Parallel Dynamic Programming for Solving the String Editing Problem on a CGM/BSP C. E. R. Alves present a coarse-grained parallel algorithm for solving the string edit distance problem for a string A and all substrings of a string C. Our method is based on a novel CGM/BSP parallel dynamic programming
Harmonic coordinates in the string and membrane equations
Chun-Lei He; Shou-Jun Huang
2010-04-16
In this note, we first show that the solutions to Cauchy problems for two versions of relativistic string and membrane equations are diffeomorphic. Then we investigate the coordinates transformation presented in Ref. [9] (see (2.20) in Ref. [9]) which plays an important role in the study on the dynamics of the motion of string in Minkowski space. This kind of transformed coordinates are harmonic coordinates, and the nonlinear relativistic string equations can be straightforwardly simplified into linear wave equations under this transformation.
Dynamics of a global string with large Higgs boson mass
C. Charmousis; B. Boisseau; B. Linet
1998-01-12
We consider a self-gravitating string generated by a global vortex solution in general relativity. We investigate the Einstein and field equations of a global vortex in the region of its central line and at a distance from the centre of the order of the inverse of its Higgs boson mass. By combining the two we establish by a limiting process of large Higgs mass the dynamics of a self-gravitating global string. Under our assumptions the presence of gravitation restricts the world sheet of the global string to be totally geodesic.
A note on string size evolution in phantom cosmology
Soon-Tae Hong
2015-04-05
We analyze evolution of string size in higher-dimensional cosmology with phantom field. Assuming that the Universe possesses the phantom field defined in a ten-dimensional spacetime, we predict string size which is claimed to be that of photon in nature at present. The Universe size increases as in the standard inflationary Universe model while the photon size decreases drastically at the early stage of the string evolution after the Big Bang. Moreover, the photon spin in the phantom Universe is analyzed in the framework of the stringy cosmology.
Lovelock black hole thermodynamics in a string cloud model
Lee, Tae-Hun; Maharaj, Sunil D; Baboolal, Dharmanand
2015-01-01
The Lovelock theory is an extension of general relativity to higher dimensions. We study the Lovelock black hole for a string cloud model in arbitrary dimensional spacetime, and in turn also analyze its thermodynamical properties. Indeed, we compute the mass, temperature and entropy of the black hole and also perform a thermodynamical stability analysis. The phase structure suggests that the Hawking-Page phase transition is achievable. It turns out that the presence of the Lovelock terms and/or background string cloud completely changes the black hole thermodynamics. Interestingly, the entropy of a black hole is unaffected due to a background string cloud, but has a correction term due to Lovelock gravity.
First Structure Formation: II. Cosmic String + Hot Dark Matter Models
Tom Abel; Albert Stebbins; Peter Anninos; Michael L. Norman
1997-06-26
We examine the structure of baryonic wakes in the cosmological fluid which would form behind GUT-scale cosmic strings at early times (redshifts z > 100) in a neutrino-dominated universe. We show, using simple analytical arguments as well as 1- and 2-dimensional hydrodynamical simulations, that these wakes will NOT be able to form interesting cosmological objects before the neutrino component collapses. The width of the baryonic wakes (< 10 kpc comoving) is smaller than the scale of wiggles on the strings and are probably not enhanced by the wiggliness of the string network.
Width of the Confining String in Yang-Mills Theory
Gliozzi, F.; Pepe, M.; Wiese, U.-J.
2010-06-11
We investigate the transverse fluctuations of the confining string connecting two static quarks in (2+1)D SU(2) Yang-Mills theory using Monte Carlo calculations. The exponentially suppressed signal is extracted from the large noise by a very efficient multilevel algorithm. The resulting width of the string increases logarithmically with the distance between the static quark charges. Corrections at intermediate distances due to universal higher-order terms in the effective string action are calculated analytically. They accurately fit the numerical data.
Modified Dispersion Relations from Closed Strings in Toroidal Cosmology
Mar Bastero-Gil; Paul H. Frampton; Laura Mersini
2002-02-13
A long-standing problem of theoretical physics is the exceptionally small value of the cosmological constant $\\Lambda \\sim 10^{-120}$ measured in natural Planckian units. Here we derive this tiny number from a toroidal string cosmology based on closed strings. In this picture the dark energy arises from the correlation between momentum and winding modes that for short distances has an exponential fall-off with increasing values of the momenta.The freeze-out by the expansion of the background universe for these transplanckian modes may be interpreted as a frozen condensate of the closed-string modes in the three non-compactified spatial dimensions.
Dark Energy Generated by Warped Cosmic Strings
Reinoud Jan Slagter
2014-07-29
If we live on the weak brane in a warped 5D bulk spacetime, gravitational waves and brane fluctuations can be generated by a part of the 5D Weyl tensor and carries information of the gravitational field outside the brane. We consider the U(1) self-gravitating scalar-gauge field on the warped spacetime without bulk matter. It turns out that "branons" can be formed dynamically, due to the modified energy-momentum tensor components of the cosmic string. It turns out that the parameter $\\alpha$, i.e., the gauge-to-scalar mass, changes from a value $>1$ to a value $wave energy. It is the time-dependent part of the warp factor which triggers this extraordinary behavior.
Conformable apparatus in a drill string
Hall, David R. (Provo, UT); Hall, Jr., H. Tracy (Provo, UT); Pixton, David S. (Lehi, UT); Fox, Joe (Spanish Fork, UT)
2007-08-28
An apparatus in a drill string comprises an internally upset drill pipe. The drill pipe comprises a first end, a second end, and an elongate tube intermediate the first and second ends. The elongate tube and the ends comprising a continuous an inside surface with a plurality of diameters. A conformable metal tube is disposed within the drill pipe intermediate the ends thereof and terminating adjacent to the ends of the drill pipe. The conformable metal tube substantially conforms to the continuous inside surface of the metal tube. The metal tube may comprise a non-uniform section which is expanded to conform to the inside surface of the drill pipe. The non-uniform section may comprise protrusions selected from the group consisting of convolutions, corrugations, flutes, and dimples. The non-uniform section extends generally longitudinally along the length of the tube. The metal tube may be adapted to stretch as the drill pipes stretch.
String Theory, Supersymmetry, Unification, and All That
John H. Schwarz; Nathan Seiberg
1998-04-22
String theory and supersymmetry are theoretical ideas that go beyond the standard model of particle physics and show promise for unifying all forces. After a brief introduction to supersymmetry, we discuss the prospects for its experimental discovery in the near future. We then show how the magic of supersymmetry allows us to solve certain quantum field theories exactly, thus leading to new insights about field theory dynamics related to electric-magnetic duality. The discussion of superstring theory starts with its perturbation expansion, which exhibits new features including ``stringy geometry.'' We then turn to more recent non-perturbative developments. Using new dualities, all known superstring theories are unified, and their strong coupling behavior is clarified. A central ingredient is the existence of extended objects called branes.
String Gas Shells, their Dual Radiation and Hedgehog Signature Control
E. I. Guendelman
2009-03-12
We search for spherically symmetric, stationary solutions with a string gas shell as a source. The requirement of a uniform newtonian potential, or constancy of the 00 component of the metric, implies the existence of a "dual" radiation, which we argue can be interpreted as representing the virtual quantum fluctuations that stabilize the shell. A string hedgehog can be introduced also into the solution. For zero or small hedgehog strength the string gas shell is of a regular nature, while the dual radiation is of a spacelike nature. For higher hedgehog strengths however the radiation "materializes" and becomes timelike while the string gas shell becomes space like. The significance of these solutions for the quantum theory is discussed.
LHC Olympics Workshop and String Phenomenology 2006 Conference
David Gross
2006-10-01
This is the final report of the organizers of the String Phenomenolgy program of which the LHC Olympics and the String Phenomenolgy conference were a part. In addition, it includes the list of talks from our website which comprise the online proceedings. The KITP no longer publishes conferences proceedings but rather makes recordings and visuals of all talks available on its website at www.kitp.ucsb.edu Program talks are available at http://online.kitp.ucsb.edu/online/strings06/ Conference talks are are at http://online.itp.ucsb.edu/online/strings_c06/ and LHC Olympics talks are at http://online.itp.ucsb.edu/online/lhco_c06/. These talks constitute the proceedings of these meetings.
Phenomenology of heterotic and type II orientifold string models
Mayes, Van Eric
2009-05-15
Cryptons are metastable bound states of fractionally-charged particles that arise generically in the hidden sectors of models derived from heterotic string. We study their properties and decay modes in a speci?c ?ipped ...
Assessment of Olefin-BasedIUD Tail Strings David Roylance
Roylance, David
the controversy over the Dalkon Shield multi- filamentary tail string, it would appear prudent to use are met by olefin (specifically polyethylene and polypropylene) polymers that have been extruded
Self-Dual Supergravity from N = 2 Strings
de Boer, J.
2010-01-01
the difference between the RNS formulation of the (1,2)to the conventional N = 1 RNS string through a non-localto formulate our model in RNS variables. One immediate
The Wigner Function of Produced Particles in String Fragmentation
Cheuk-Yin Wong
2009-11-05
We show that QCD4 with transverse confinement can be approximately compactified into QCD2 with a transverse quark mass $m_{{}_T}$ that is obtained by solving a set of coupled transverse eigenvalue equations. In the limits of a strong coupling and a large number of flavors, QCD2 further admits Schwinger QED2-type bosonized solutions. We therefore examine phenomenologically the space-time dynamics of produced particles in string fragmentation by studying the Wigner function of produced bosons in Schwinger QED2, which mimics many features of string fragmentation in quantum chromodynamics. We find that particles with momenta in different regions of the rapidity plateau are produced at the initial moment of string fragmentation as a quark pulls away from an antiquark at high energies, in contrast to classical pictures of string fragmentation with longitudinal space-momentum-time ordering.
Towards a metamaterial simulation of a spinning cosmic string
Tom G. Mackay; Akhlesh Lakhtakia
2009-11-21
Establishing the constitutive parameters of a nonhomogeneous bianisotropic medium that is equivalent to the spacetime metric of a spinning cosmic string, in a noncovariant formalism, we found a metamaterial route to investigate the existence of closed timelike curves.
Regge behavior saves String Theory from causality violations
D'Appollonio, Giuseppe; Russo, Rodolfo; Veneziano, Gabriele
2015-01-01
Higher-derivative corrections to the Einstein-Hilbert action are present in bosonic string theory leading to the potential causality violations recently pointed out by Camanho et al. We analyze in detail this question by considering high-energy string-brane collisions at impact parameters $b \\le l_s$ (the string-length parameter) with $l_s \\gg R_p$ (the characteristic scale of the D$p$-brane geometry). If we keep only the contribution of the massless states causality is violated for a set of initial states whose polarization is suitably chosen with respect to the impact parameter vector. Such violations are instead neatly avoided when the full structure of string theory - and in particular its Regge behavior - is taken into account.
Regge behavior saves String Theory from causality violations
Giuseppe D'Appollonio; Paolo Di Vecchia; Rodolfo Russo; Gabriele Veneziano
2015-05-12
Higher-derivative corrections to the Einstein-Hilbert action are present in bosonic string theory leading to the potential causality violations recently pointed out by Camanho et al. We analyze in detail this question by considering high-energy string-brane collisions at impact parameters $b \\le l_s$ (the string-length parameter) with $l_s \\gg R_p$ (the characteristic scale of the D$p$-brane geometry). If we keep only the contribution of the massless states causality is violated for a set of initial states whose polarization is suitably chosen with respect to the impact parameter vector. Such violations are instead neatly avoided when the full structure of string theory - and in particular its Regge behavior - is taken into account.
N=2 String as a Topological Conformal Algebra
J. Gomis; H. Suzuki
1991-11-28
We prove that critical and subcritical N=2 string theory gives a realization of an N=2 superfield extension of the topological conformal algebra. The essential observation is the vanishing of the background charge.
Closed tachyon solitons in type II string theory
Iñaki García-Etxebarria; Miguel Montero; Angel M. Uranga
2015-05-20
Type II theories can be described as the endpoint of closed string tachyon condensation in certain orbifolds of supercritical type 0 theories. In this paper, we study solitons of this closed string tachyon and analyze the nature of the resulting defects in critical type II theories. The solitons are classified by the real K-theory groups KO of bundles associated to pairs of supercritical dimensions. For real codimension 4 and 8, corresponding to $KO({\\bf S}^4)={\\bf Z}$ and $KO({\\bf S}^8)={\\bf Z}$, the defects correspond to a gravitational instanton and a fundamental string, respectively. We apply these ideas to reinterpret the worldsheet GLSM, regarded as a supercritical theory on the ambient toric space with closed tachyon condensation onto the CY hypersurface, and use it to describe charged solitons under discrete isometries. We also suggest the possible applications of supercritical strings to the physical interpretation of the matrix factorization description of F-theory on singular spaces.
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Light-Emitting diodes (LEDs) efficiently produce light in a fundamentally different way than any legacy or traditional source of light.
Gauged Nambu-Jona-Lasinio model and axionic QCD string
Chi Xiong
2014-12-30
We propose an axionic QCD string scenario based on the original flux-tube model by Kogut and Susskind, and then incorporate it into a gauged Nambu-Jona-Lasinio (NJL) model. Axial anomaly is studied by a new topological coupling from the string side, and by the 't Hooft vortex from the NJL side, respectively. The nontrivial phase distribution of the quark condensate plays an important role in this scenario.
Non-Abelian String of a Finite Length
Monin, Sergey; Yung, Alexei
2015-01-01
We consider world-sheet theories for non-Abelian strings assuming compactification on a cylinder with a finite circumference $L$ and periodic boundary conditions. The dynamics of the orientational modes is described by two-dimensional CP$(N-1)$ model. We analyze both non-supersymmetric (bosonic) model and ${\\mathcal N}=(2,2)$ supersymmetric CP$(N-1)$ emerging in the case of 1/2-BPS saturated strings in \
Non-Abelian String of a Finite Length
Sergey Monin; Mikhail Shifman; Alexei Yung
2015-05-28
We consider world-sheet theories for non-Abelian strings assuming compactification on a cylinder with a finite circumference $L$ and periodic boundary conditions. The dynamics of the orientational modes is described by two-dimensional CP$(N-1)$ model. We analyze both non-supersymmetric (bosonic) model and ${\\mathcal N}=(2,2)$ supersymmetric CP$(N-1)$ emerging in the case of 1/2-BPS saturated strings in \
Mellin-Barnes Representation of the Topological String
Krefl, Daniel
2015-01-01
We invoke integrals of Mellin-Barnes type to analytically continue the Gopakumar-Vafa resummation of the topological string free energy in the string coupling constant, leading to additional non-perturbative terms. We also discuss in a similar manner the refined and Nekrasov-Shatashvili limit version thereof. The derivation is straight-forward and essentially boils down to taking residue. This allows us to confirm some related conjectures in the literature at tree-level.
High-Energy Scattering vs Static QCD Strings
V. A. Petrov; R. A. Ryutin
2014-09-30
We discuss the shape of the interaction region of the elastically scattered protons stipulated by the high-energy Pomeron exchange which turns out to be very similar with the shape of the static string representing the confining QCD flux tube. This similarity disappears when we enter the LHC energy region, which corresponds to many-Pomeron exchanges. Reversing the argument we conjecture a modified relationship between the width and the length of the confining string at very large lengths.
Spiky Strings on AdS(4) X CP**3
Bum-Hoon Lee; Kamal L. Panigrahi; Chanyong Park
2008-11-07
We study a giant magnon and a spike solution for the string rotating on AdS(4) X CP**3 geometry. We consider rigid rotating fundamental string in the SU(2) X SU(2) sector inside the CP**3 and find out the general form of all the conserved charges. We find out the dispersion relation corresponding to both the known giant magnon and the new spike solutions. We further study the finite size correction in both cases.
Radio Jets and Galaxies as Cosmic String Probes
Fa-bo Feng
2012-07-17
The lensing effect of a cosmic string is studied, and some new methods are proposed to detect the cosmic string. The technique for using jets as extended gravitational lensing probes was firstly explored by Kronberg. We use the "alignment-breaking parameter" $ \\eta_G $ as a sensitive indicator of gravitational distortion by a wiggly cosmic string. Then, we applied the non-constant deflection angle to jets, and $ \\eta_G $ of a specific jet is just related to the projected slope of the jet. At least three jets in the sample of Square Kilometer Array (SKA) would have significant signals ($ \\eta_G >10^\\circ $) if the wiggly infinite cosmic string existed. The distortion of elliptical object is also studied and used to do a statistical research on directions of axes and ellipticities of galaxies. In the direction of the string, we find that galaxies appear to be more elliptical for an observer and the distribution of apparent ellipticity changes correspondingly. Ellipticity distribution of current SDSS spiral sample has the signal-to-noise ratio up to 8.48 which is large enough for astronomical observations. The future survey, such as Large Synoptic Survey Telescope (LSST) and Dark Energy Survey (DES), would weaken the requirement of special geometry in the data processing. As a result, all kinds of distributions, including ellipticity axis distribution, would serve as probes to detect wiggly strings in the near future. In brief, if a wiggly cosmic string existed, these signals would be convenient to be observed with the future weak lensing survey or other surveys in deep space. If there was no lensing signal in these distributions, it would give the upper limit of the abundance of infinite strings.
Self-avoiding effective strings in lattice gauge theories
M. Caselle; F. Gliozzi
1991-11-28
It is shown that the effective string recently introduced to describe the long distance dynamics of 3D gauge systems in the confining phase has an intriguing description in terms of models of 2D self-avoiding walks in the dense phase. The deconfinement point, where the effective string becomes N=2 supersymmetric, may then be interpreted as the tricritical Theta point where the polymer chain undergoes a collapse transition. As a consequence, a universal value of the deconfinement temperature is predicted.
Post-Holiday Holiday Shopping | Department of Energy
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Sandia Energy - (Lighting and) Solid-State Lighting: Science...
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(Lighting and) Solid-State Lighting: Science, Technology, Economic Perspectives Home Energy Research EFRCs Solid-State Lighting Science EFRC (Lighting and) Solid-State Lighting:...
Sustainable Office Lighting Options
Massachusetts at Amherst, University of
Sustainable Office Lighting Options Task Lighting: Task lighting is a localized method of lighting a workspace so that additional, unnecessary lighting is eliminated, decreasing energy usage and costs. Illumination levels in the targeted work areas are higher with task lighting than with the ambient levels
Streched String with Self-Interaction at the Hagedorn Point: Spatial Sizes and Black Hole
Qian, Yachao
2015-01-01
We analyze the length, mass and spatial distribution of a discretized transverse string in $D_\\perp$ dimensions with fixed end-points near its Hagedorn temperature. We suggest that such a string may dominate the (holographic) Pomeron kinematics for dipole-dipole scattering at intermediate and small impact parameters. Attractive self-string interactions cause the transverse string size to contract away from its diffusive size, a mechanism reminiscent of the string-black-hole transmutation. The string shows sizable asymmetries in the transverse plane that translate to primordial azimuthal asymmetries in the stringy particle production in the Pomeron kinematics for current pp and pA collisions at collider energies.
Streched String with Self-Interaction at the Hagedorn Point: Spatial Sizes and Black Hole
Yachao Qian; Ismail Zahed
2015-08-15
We analyze the length, mass and spatial distribution of a discretized transverse string in $D_\\perp$ dimensions with fixed end-points near its Hagedorn temperature. We suggest that such a string may dominate the (holographic) Pomeron kinematics for dipole-dipole scattering at intermediate and small impact parameters. Attractive self-string interactions cause the transverse string size to contract away from its diffusive size, a mechanism reminiscent of the string-black-hole transmutation. The string shows sizable asymmetries in the transverse plane that translate to primordial azimuthal asymmetries in the stringy particle production in the Pomeron kinematics for current pp and pA collisions at collider energies.
UF Carillon Studio Holiday Recital
Dranishnikov, Alexander
floor of the tower were cast in 1978 by the firm of Koninklijke Eijsbouts (Royal Dutch Bell Foundry) of Asten, The Netherlands. The bronze bells were tuned at the foundry by carefully shaving metal from
Holiday Plants with Toxic Misconceptions
Evens, Zabrina N; Stellpflug, Samuel J
2012-01-01
1999;41:394-7. the American Association of Poison ControlCenters’ National Poison 21. Kramer R. BittersweetMinnesota Hennepin Regional Poison Center, Minneapolis,
holiday | National Nuclear Security Administration
National Nuclear Security Administration (NNSA)
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Helping make the holidays happier
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Naked singularities in low energy, effective string theory
Sayan Kar
1998-04-05
Solutions to the equations of motion of the low energy, effective field theory emerging out of compactified heterotic string theory are constructed by making use of the well-known duality symmetries. Beginning with four-dimensional solutions of the Einstein-massless scalar field theory in the canonical frame we first rewrite the corresponding solutions in the string frame. Thereafter, using the T and S duality symmetries of the low energy string effective action we arrive at the corresponding uncharged, electrically charged and magnetically charged solutions. Brief comments on the construction of dual versions of the Kerr-Sen type using the dilatonic Kerr solution as the seed are also included. Thereafter, we verify the status of the energy conditions for the solutions in the string frame. Several of the metrics found here are shown to possess naked singularities although the energy conditions are obeyed. Dual solutions exhibit a duality in the conservation/violation of the Null and Averaged Null Energy Conditions (NEC/ANEC), a fact demonstrated earlier in the context of black holes (hep-th/9604047) and cosmologies (hep-th/9611122). Additionally, those backgrounds which conserve the NEC/ANEC in spite of possesing naked singularities serve as counterexamples to cosmic censorship in the context of low energy, effective string theory.
Testing Problem Solving in Ravens: String-Pulling to Reach Food Bernd Heinrich & Thomas Bugnyar
Indiana University
the string to lift the meat. A second group of birds with similar exposure to strings but without any Bugnyar, Konrad Lorenz Research Station and Department of Behaviour, Neurobiology, and Cognition
String Bits at Finite Temperature and the Hagedorn Phase
Charles B. Thorn
2015-07-10
We study the behavior of a simple string bit model at finite temperature. We use thermal perturbation theory to analyze the high temperature regime. But at low temperatures we rely on the large $N$ limit of the dynamics, for which the exact energy spectrum is known. Since the lowest energy states at infinite $N$ are free closed strings, the $N=\\infty$ partition function diverges above a finite temperature $\\beta_H^{-1}$, the Hagedorn temperature. We argue that in these models at finite $N$, which then have a finite number of degrees of freedom, there can be neither an ultimate temperature nor any kind of phase transition. We discuss how the discontinuous behavior seen at infinite $N$ can be removed at finite $N$. In this resolution the fundamental string bit degrees of freedom become more active at temperatures near and above the Hagedorn temperature.
Clouds of strings in third-order Lovelock gravity
Sushant G. Ghosh; Uma Papnoi; Sunil D. Maharaj
2014-08-20
Lovelock theory is a natural extension of the Einstein theory of general relativity to higher dimensions in which the first and second orders correspond, respectively, to general relativity and Einstein-Gauss-Bonnet gravity. We present exact black hole solutions of $D\\geq 4$-dimensional spacetime for first-, second-, and third-order Lovelock gravities in a string cloud background. Further, we compute the mass, temperature, and entropy of black hole solutions for the higher-dimensional general relativity and Einstein-Gauss-Bonnet theories and also perform thermodynamic stability of black holes. It turns out that the presence of the Gauss-Bonnet term and/or background string cloud completely changes the black hole thermodynamics. Interestingly, the entropy of a black hole is unaffected due to a background string cloud. We rediscover several known spherically symmetric black hole solutions in the appropriate limits.
Solution of the string equations for asymmetric potentials
Patrick Waters
2015-06-22
We consider the large $N$ expansion of the partition function for the Hermitian one-matrix model. It is well known that the coefficients of this expansion are generating functions $F^{(g)}$ for a certain kind of graph embedded in a Riemann surface. Other authors have made a simplifying assumption that the potential $V$ is an even function. We present a method for computing $F^{(g)}$ in the case that $V$ is not an even function. Our method is based on the string equations, and yields "valence independent" formulas which do not depend explicitly on the potential. We introduce a family of differential operators, the "string polynomials", which make clear the valence independent nature of the string equations.
Toroidal Orbifolds: Resolutions, Orientifolds and Applications in String Phenomenology
Reffert, S
2006-01-01
This thesis is concerned with the geometry of toroidal orbifolds and their applications in string theory. By resolving the orbifold singularities via blow-ups, one arrives at a smooth Calabi-Yau manifold. The systematic method to do so is explained in detail. Also the transition to the Orientifold quotient is explained. In the second part of this thesis, applications in string phenomenology are discussed. The applications belong to the framework of compactifications with fluxes in type IIB string theory. The first example belongs to the category of model building, flux-induced soft supersymmetry breaking parameters are worked out explicitly. The second example belongs to the subject of moduli stabilization along the lines of the KKLT proposal. Orientifold models which result from resolutions of toroidal orbifolds are discussed as possible candidate models for an explicit realization of the KKLT proposal.
Baker, W.S.
1991-04-01
This report covers many aspects of various lighting options for homes. Types of light sources described include natural light, artificial light, incandescent lamps, fluorescent lamps, and high intensity discharge lamps. A light source selection guide gives the physical characteristics of these, design considerations, and common applications. Color, strategies for efficient lighting, and types of lighting are discussed. There is one section giving tips for various situations in specific rooms. Rooms and types of fixtures are shown on a matrix with watts saved by using the recommended type lighting for that room and room location. A major emphasis of this report is saving energy by utilizing the most suitable, recommended lighting option. (BN)
Instability of Axions and Photons In The Presence of Cosmic Strings
Eduardo I. Guendelman; Idan Shilon
2008-10-26
We report that axions and photons exhibit instability in the presence of cosmic strings that are carrying magnetic flux in their core. The strength of the instability is determined by the symmetry breaking scale of the cosmic string theory. This result would be evident in gamma ray bursts and axions emanating from the cosmic string. These effects will eventually lead to evaporation of the cosmic string.
Theoretical Research in Cosmology, High-Energy Physics and String Theory
Ng, Y Jack; Dolan, Louise; Mersini-Houghton, Laura; Frampton, Paul
2013-07-29
The research was in the area of Theoretical Physics: Cosmology, High-Energy Physics and String Theory
Roe, George Michael; Klebanoff, Leonard Elliott; Rea, Gerald W; Drake, Robert A; Johnson, Terry A; Wingert, Steven John; Damberger, Thomas A; Skradski, Thomas J; Radley, Christopher James; Oros, James M; Schuttinger, Paul G; Grupp, David J; Prey, Stephen Carl
2013-05-14
A mobile lighting apparatus includes a portable frame such as a moveable trailer or skid having a light tower thereon. The light tower is moveable from a stowed position to a deployed position. A hydrogen-powered fuel cell is located on the portable frame to provide electrical power to an array of the energy efficient lights located on the light tower.
Bounds on topological Abelian string-vortex and string-cigar from information-entropic measure
Correa, R A C; Almeida, C A S; da Rocha, Roldao
2016-01-01
In this work we obtain bounds on topological Abelian string-vortex in six dimensions using a new measure of configurational complexity known as configurational entropy. In this way, the information-theoretical measure of six dimensional braneworlds scenarios are capable to probe situations where the parameters responsible for the thickness are arbitrary. The so-called Configurational Entropy (CE) selects the best value of the parameter in the model. This is accomplished by minimizing the CE, namely, by selecting the most appropriate parameters in the model that correspond to the most organized system, based upon Shannon information theory. This information-theoretical measure of complexity provides a complementary perspective to situations where strictly energy-based arguments are inconclusive. We show that the higher the energy the higher the configurational entropy, what shows an important correlation between the energy of the a localized field configuration and its associated entropic measure.
Quantization of Dyon Charge and Electric-Magnetic Duality in String Theory
Ashoke Sen
1992-09-05
We analyze the allowed spectrum of electric and magnetic charges carried by dyons in (toroidally compactified) heterotic string theory in four dimensions at arbitrary values of the string coupling constant and $\\theta$ angle. The spectrum is shown to be invariant under electric-magnetic duality transformation, thereby providing support to the conjecture that this is an exact symmetry in string theory.
Preprint typeset in JHEP style. PAPER VERSION CLNS00/1704 String Webs from Field Theory
Preprint typeset in JHEP style. PAPER VERSION CLNS00/1704 String Webs from Field Theory Philip C of the stable supersym metric spectrum is a generalization of the ``string web'' picture of these states found.3 Recovery of a string junction picture 18 4. BPS states in N=4 SU(N) theories 19 4.1 BPS states as webs
Parallel Dynamic Programming for Solving the String Editing Problem on a CGM/BSP
Song, Siang Wun
Parallel Dynamic Programming for Solving the String Editing Problem on a CGM/BSP C. E. R. Alves, string editing, dynamic programming, CGM, BSP # Partially supported by CNPq and FINEPPRONEXSAI Proc. No. net ABSTRACT In this paper we present a coarsegrained parallel algorithm for solving the string edit
MUS420/EE367A Lecture 7B Digital Waveguide Modeling of Bowed Strings
Smith III, Julius Orion
= Friction Curve × Differential Velocity Reaction Force = String Wave Impedance × Velocity Change · Nominally StringBow Bow Velocity (Primary Control) Bow Force Bow Position BridgeString-1 Nut or Finger Lowpass Body into two sections · Bow junction = nonlinear two-port · Primary control variable = bow velocity velocity
Power Towers of String Instantons for N=1 Vacua
Ralph Blumenhagen; Maximilian Schmidt-Sommerfeld
2008-03-11
We provide arguments for the existence of novel hereinafter called poly-instanton corrections to holomorphic couplings in four-dimensional N=1 supersymmetric string compactifications. After refining quantitatively the D-brane instanton calculus for corrections to the gauge kinetic function, we explicitly apply it to the Type I toroidal orbifold defined in arXiv:0710.3080 and compare the results to the proposed heterotic S-dual model. This leads us to the intriguing conclusion that N=1 string vacua feature a power tower like proliferation of instanton corrections.
Generalized dilaton-Maxwell cosmic string and wall solutions
John Morris
2006-08-15
The class of static solutions found by Gibbons and Wells for dilaton-electrodynamics in flat spacetime, which describe nontopological strings and walls that trap magnetic flux, is extended to a class of dynamical solutions supporting arbitrarily large, nondissipative traveling waves, using techniques previously applied to global and local topological defects. These solutions can then be used in conjunction with S-duality to obtain more general solitonic solutions for various axidilaton-Maxwell theories. As an example, a set of dynamical solutions is found for axion, dilaton, and Maxwell fields in low energy heterotic string theory using the SL(2,R) invariance of the equations of motion.
Kerr-NUT-AdS metrics and string theory
Chen, Wei
2008-10-10
are then described as the exchanges of gauge bosons in an SU(3)×SU(2)×U(1) symmetry group. The Standard Model is quite successful in explaining the experimental data, and in fact it agrees with all of our observations of the physical world. However, a major problem..., string theory has been deemed to be a very promising can- didate for the unification theory of everything. The spectrum of bosonic particles may be explained as the various excitations of strings, and this spectrum automat- ically contains a massless spin...
Finite Energy Solutions in Three-Dimensional Heterotic String Theory
Michele Bourdeau; Gabriel Lopes Cardoso
1997-09-24
We show that a large class of supersymmetric solutions to the low-energy effective field theory of heterotic string theory compactified on a seven torus can have finite energy, which we compute. The mechanism by which these solutions are turned into finite energy solutions is similar to the one occurring in the context of four-dimensional stringy cosmic string solutions. We also describe the solutions in terms of intersecting eleven-dimensional M-branes, M-waves and M-monopoles.
Physical Interpretation of the 26 Dimensions of Bosonic String Theory
Frank D. Smith Jr
2002-07-15
The 26 dimensions of Closed Unoriented Bosonic String Theory are interpreted as the 26 dimensions of the traceless Jordan algebra J3(O)o of 3x3 Octonionic matrices, with each of the 3 Octonionic dimenisons of J3(O)o having the following physical interpretation: 4-dimensional physical spacetime plus 4-dimensional internal symmetry space; 8 first-generation fermion particles; 8 first-generation fermion anti-particles. This interpretation is consistent with interpreting the strings as World Lines of the Worlds of Many-Worlds Quantum Theory and the 26 dimensions as the degrees of freedom of the Worlds of the Many-Worlds.
Note on Structure Formation from Cosmic String Wakes
Duplessis, Francis
2013-01-01
The search for cosmic strings has been of renewed interest with the advent of precision cosmology. In this note we give a quantitative description of the nonlinear matter density fluctuations that can form from a scaling network of cosmic string wakes. Specifically, we compute the distribution of dark matter halos. These halos would possess strong correlations in position space that should have survived until today. We also discuss the challenges involved in their detection due to their small size and the complex dynamics of their formation.
Coset Symmetries in Dimensionally Reduced Bosonic String Theory
N. D. Lambert; P. C. West
2001-08-02
We discuss the dimensional reduction of various effective actions, particularly that of the closed Bosonic string and pure gravity, to two and three dimensions. The result for the closed Bosonic string leads to coset symmetries which are in agreement with those recently predicted and argued to be present in a new unreduced formulation of this theory. We also show that part of the Geroch group appears in the unreduced duality symmetric formulation of gravity recently proposed. We conjecture that this formulation can be extended to a non-linear realisation based on a Kac-Moody algebra which we identify. We also briefly discuss the proposed action of Bosonic M-theory.
Anyonic glueballs from an effective-string model
Buisseret, Fabien
2015-01-01
Relying on an effective-string approach in which glueballs --- bound states of pure Yang-Mills theory --- are modelled by closed strings, we give arguments suggesting that anyonic glueballs, \\textit{i.e.} glueballs with arbitrary spin, may exist in $(2+1)$-$\\,$dimensional Yang-Mills theory. We then focus on the large$\\,$-$N_c$ limit of $SU$($N_c$) Yang-Mills theory and show that our model leads to a mass spectrum in good agreement with lattice data in the scalar sector, while it predicts the masses and spins of anyonic glueball states.
Edge Detection, Cosmic Strings and the South Pole Telescope
Andrew Stewart; Robert Brandenberger
2009-01-07
We develop a method of constraining the cosmic string tension $G\\mu$ which uses the Canny edge detection algorithm as a means of searching CMB temperature maps for the signature of the Kaiser-Stebbins effect. We test the potential of this method using high resolution, simulated CMB temperature maps. By modeling the future output from the South Pole Telescope project (including anticipated instrumental noise), we find that cosmic strings with $G\\mu > 5.5\\times10^{-8}$ could be detected.
Practical image based lighting
Lee, Jaemin
2003-01-01
information is lighting. Image based lighting that is developed to recover illumination information of the real world from photographs has recently been popular in computer graphics. In this thesis we present a practical image based lighting method. Our...
Srinivasan, Kavita, 1976-
2002-01-01
This thesis focuses on enhancing the awareness of light for the pedestrian,and using light as a way of revealing the structure of the city and its relation to the cosmos. It proposes that aesthetic qualities of light inform ...
Tumber, A. J.
1981-01-01
Increasing electricity costs have made a significant impact on lighting. The Illuminating Engineering society (I.E.S.) and the lighting industry are producing new standards, procedures and products to make lighting more appropriate and energy...
Natural lighting and skylights
Evans, Benjamin Hampton
1961-01-01
There are many physiological and psychological factors which enter into the proper design of space for human occupancy. One of these elements is light. Both natural light and manufactured light are basic tools with which any designer must work...
Powell, John William
1989-01-01
Specific light is defined as light from artificial or altered natural sources. The use and manipulation of light in three dimensional sculptural work is discussed in an historic and contemporary context. The author's work ...
Advanced Demand Responsive Lighting
Advanced Demand Responsive Lighting Host: Francis Rubinstein Demand Response Research Center demand responsive lighting systems Importance of dimming New wireless controls technologies · Advanced Demand Responsive Lighting (commenced March 2007) #12;Objectives · Provide up-to-date information
Light Duty Combustion Research: Advanced Light-Duty Combustion...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Light Duty Combustion Research: Advanced Light-Duty Combustion Experiments Light Duty Combustion Research: Advanced Light-Duty Combustion Experiments 2009 DOE Hydrogen Program and...
Lighting in Commercial Buildings
U.S. Energy Information Administration (EIA) Indexed Site
are also under consideration. Outside the DOE, the Environmental Protection Agency's Green Lights program promotes energy-efficient lighting as a means to reducing...
Lighting in Commercial Buildings
U.S. Energy Information Administration (EIA) Indexed Site
Motivation and Computation of Lighting Measures Floorspace by Lighting Equipment Configuration As described in Appendix A, for each building b, the CBECS data set has the total...
Lighting in Commercial Buildings
U.S. Energy Information Administration (EIA) Indexed Site
more comprehensive understanding of commercial lighting and the potential for lighting energy savings. Steps to build on this analysis can be taken in many directions. One...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Join HERO for our annual Leavenworth Tree Lighting Ceremony & Shopping SATURDAY DECEMBER 12, 2015 Leavenworth Christmas Lighting Festival Visitors return year after year for some...
Lighting in Commercial Buildings
U.S. Energy Information Administration (EIA) Indexed Site
light by passing electricity through mercury vapor, which causes the fluorescent coating to glow or fluoresce. High-Efficiency Ballast (HEB): A lighting conservation feature...
Broader source: Energy.gov [DOE]
Windows that emit light and are more energy efficient? Universal Display’s PHOLED technology enables windows that have transparent light-emitting diodes in them.
Aspects of grand unified and string phenomenology
Walker, Joel Wesley
2005-11-01
the mass level ofthe two-boson, two- fermion effective vertex `a la Fermi. The upper bound on its rate translates directly to a minimal mass for the color-triplet Higgs of around 1017GeV [22]. Conversely though, compatibility of a strict unification... the five of Higgs (h) away from the light electroweak components H2. Specifically, since the flipped 10 now contains a neutral element it is possible to allow vacuum expectation values for 22 the breaking of SU(5) to arise within a Higgs decaplet H from...
Classical Worldsheets for String Scattering on Flat and AdS Spacetime
Charles M. Sommerfield; Charles B. Thorn
2008-05-21
We present a study of the worldsheets that describe the classical limit of various string scattering processes. Our main focus is on string scattering in AdS spacetime because of its relation via the AdS/CFT correspondence to gluon scattering in {\\cal N}=4 supersymmetric Yang-Mills theory. But we also consider analogous processes in flat Minkowski spacetime which we compare to the AdS case. In addition to scattering of string by string we also find and study worldsheets describing the scattering of a string by external sources.
Landscape statistics of the low autocorrelated binary string problem
Stadler, Peter F.
, NM 87501, USA Abstract. The statistical properties of the energy landscape of the low autocorrelated]. In this contribution we carry out a thorough investigation of the statistical properties of the energy landscapeLandscape statistics of the low autocorrelated binary string problem Fernando F. Ferreira a , Jos
Landscape statistics of the low autocorrelated binary string problem
Stadler, Peter F.
, NM 87501, USA Abstract. The statistical properties of the energy landscape of the low autocorrelated]. In this contribution we carry out a thorough investigation of the statistical properties of the energy landscapeLandscape statistics of the low autocorrelated binary string problem Fernando F. Ferreiraa , Jos
Phases in String Theory A thesis submitted to
Phases in String Theory A thesis submitted to Tata Institute of Fundamental Research, Mumbai, India Institute of Fundamental Research Mumbai - 400 005, India July 2013 #12;#12;Declaration This thesis, at the Tata Institute of Fundamental Research, Mumbai. (Prithvi Narayan P) In my capacity as the supervisor
HBT puzzle at RHIC AMPT model with String Melting
Lin, Zi-wei
/RsideSmall radii Small duration time dt by Stephen Johnson at RWW02 One way out: Hydro Softest point in EOS Measured extensively in heavy ion collisions reasonably described by models (hydro-ph/01120062 recent hydro studies: #12;HIJING energy in strings(soft) and minijet partons(hard) ZPC (Zhang
Flux-induced Isometry Gauging in Heterotic Strings
Chuang, Wu-yen; Gao, Peng
2007-01-05
We study the effect of flux-induced isometry gauging of the scalar manifold in N = 2 heterotic string compactification with gauge fluxes. We show that a vanishing theorem by Witten provides the protection mechanism. The other ungauged isometries in hyper moduli space could also be protected, depending on the gauge bundle structure. We also discuss the related issue in IIB setting.
Combinatorial Problems on Strings with Applications to Protein Folding
Newman, Alantha
Combinatorial Problems on Strings with Applications to Protein Folding Alantha Newman MIT San Jose, CA 95120, USA ruhl@almaden.ibm.com Abstract We consider the problem of protein folding in linear time. 1 Introduction We consider the problem of protein folding in the HP model on the three
Renewal Strings for Cleaning Astronomical Databases Amos J. Storkey #
Storkey, Amos
pixel processing, and of course no imaging system is perfect. This paper looks at a class of problems strings, a probabilistic tech nique combining the Hough transform, re newal processes and hidden Markov ranging in scale from the solar neighbourhood to a significant fraction of the observable universe. Sur
Renewal Strings for Cleaning Astronomical Databases Amos J. Storkey
Storkey, Amos
pixel processing, and of course no imaging system is perfect. This paper looks at a class of problems strings, a probabilistic tech- nique combining the Hough transform, re- newal processes and hidden Markov ranging in scale from the solar neighbourhood to a significant fraction of the observable universe. Sur
Scalar Perturbations in a String Inspired Inflationary Scenario
C. E. M. Batista; J. C. Fabris
1996-02-28
We consider an inflationary model inspired in the low energy limit of string theory. In this model, the scale factor grows exponentially with time. A perturbation study is performed, and we show that there is a mode which displays an exponential growth in the perturbation of the scalar field.
Effective string theory description of the interface free energy
M. Billo; M. Caselle; L. Ferro; M. Hasenbusch; M. Panero
2007-10-09
We compare the predictions of the Nambu-Goto effective string model with a set of high precision Monte Carlo results for interfaces with periodic boundary conditions in the 3D Ising model. We compute the free energy in the covariant gauge exactly, up to the inclusion of the Liouville mode. The perturbative expansion of this result agrees both with the result evaluated several years ago by Dietz and Filk in the physical gauge and with a recent calculation with the Polchinski-Strominger action. We also derive the effective string spectrum which, because of the different boundary conditions, is very different from the well known one of Arvis. Taking into proper account the effective string corrections and exploiting some technical improvements in the simulations we obtain precise estimate of the amplitude ratios T_c/\\sqrt{sigma}, m_{0++}/\\sqrt{\\sigma} and sigma xi_{2nd}^2. We also discuss the behaviour of the effective string free energy in the dimensional reduction limit (i.e., near the deconfinement transition of the dual 3d gauge Ising model) and its relationship with the 2d Ising model interfaces
Lighting Controls | Department of Energy
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Controls Lighting Controls Use lighting controls to automatically turn lights on and off as needed, and save energy. | Photo courtesy of iStockphoto.comMaliketh. Use lighting...
Pedestrian Friendly Outdoor Lighting
Miller, N. J.; Koltai, R. N.; McGowan, T. K.
2013-12-01
The GATEWAY program followed two pedestrian-scale lighting projects that required multiple mockups – one at Stanford University in California and the other at Chautauqua Institution in upstate New York. The report provides insight into pedestrian lighting criteria, how they differ from street and area lighting criteria, and how solid-state lighting can be better applied in pedestrian applications.
Tips: Lighting | Department of Energy
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Tips: Lighting Tips: Lighting Lighting choices save you money. Energy-efficient light bulbs are available in a wide variety of sizes and shapes. Lighting choices save you money....
Gamma-ray bursts, axion emission and string theory dilaton
O. Bertolami
1999-01-14
The emission of axions from supernovae is an interesting possibility to account for the Gamma-Ray Bursts provided their energy can be effectively converted into electromagnetic energy elsewhere. The connection between supernova and gamma-ray bursts has been recently confirmed by the observed correlation between the burst of April 25, 1998 and the supernova SN1998bw. We argue that the axion convertion into photons can be more efficient if one considers the coupling between an intermediate scale axion and the string theory dilaton along with the inclusion of string loops. We also discuss the way dilaton dynamics may allow for a more effective energy exchange with electromagnetic radiation in the expansion process of fireballs.
Anomalous Soft Photons associated with Hadron Production in String Fragmentation
Cheuk-Yin Wong
2010-11-29
The bosonized QCD2+QED2 system for quarks with two flavors contains QCD2 and QED2 bound states, with an isoscalar photon at about 25 MeV and an isovector (I=1,I_3=0) photon at about 44 MeV. Consequently, when a quark and an antiquark at the two ends of a string pulls apart from each other at high energies, hadrons and soft photons will be produced simultaneously in the fragmentation of the string. The production of the QED2 soft photons in association with hadrons may explain the anomalous soft photon data in hadron-hadron collisions and e+e- annihilations at high energies.
Decay widths of lowest massive Regge excitations of open strings
Luis A. Anchordoqui; Haim Goldberg; Tomasz R. Taylor
2008-07-29
With the advent of the LHC there is widespread interest in the discovery potential for physics beyond the standard model. In TeV-scale open string theory, the new physics can be manifest in the excitation and decay of new resonant structures, corresponding to Regge recurrences of standard model particles. An essential input for the prediction of invariant mass spectra of the decay products (which could serve to identify the resonance as a string excitation) are the partial and total widths of the decay products. We present a parameter-free calculation of these widths for the first Regge recurrence of the SU(3) gluon octet, of the U(1) gauge boson which accompanies gluons in D-brane constructions, and of the quark triplet.
Generalized Duality and Singular Strings in Higher Dimensions
I. Bars; K. Sfetsos
1991-10-24
Deformations of gauged WZW actions are constructed for any pair $(G,H)$ by taking different embeddings of the gauge group $H\\subset G$ as it acts on the left and right of the group element $g$. This leads to models that are dual to each other, generalizing the axial/vector duality of the two dimensional black hole manifold. The classical equations are completely solved for any pair $(G,H)$ and in particular for the anti de Sitter string based on $SO(d- 1,2)/SO(d-1,1)$ for which the normal modes are determined. Duality is demonstrated for models that have the same set of normal modes. Concentrating on $SO(2,2)/SO(2,1)$, the metric and dilaton fields of the $d=3$ string as well as some of the dual generalizations are obtained. They have curvature singularities and represent new singular solutions of Einstein's general relativity in three dimensions.
Probing Naked Singularities in Non-supersymmetric String Vacua
P. Berglund; T. Hubsch; D. Minic
2000-12-11
We present a detailed analysis of non-supersymmetric spacetime varying string vacua which can lead to an exponential hierarchy between the electroweak and the gravitational scales. In particular, we identify a limit in which these vacua can be interpreted as supersymmetric vacua of F-theory. Furthermore, we study the properties of these solutions as seen by $D7$-brane probes and establish a non-supersymmetric analogue of the enhancon mechanism.
Boundary String Field Theory of the DDbar System
Kraus, P; Kraus, Per; Larsen, Finn
2001-01-01
We develop the boundary string field theory approach to tachyon condensation on the DDbar system. Particular attention is paid to the gauge fields, which combine with the tachyons in a natural way. We derive the RR-couplings of the system and express the result in terms of Quillen's superconnection. The result is related to an index theorem, and is thus shown to be exact.
Detecting relic gravitational radiation from string cosmology with LIGO
Bruce Allen; Ram Brustein
1996-09-05
A characteristic spectrum of relic gravitational radiation is produced by a period of ``stringy inflation" in the early universe. This spectrum is unusual, because the energy-density rises rapidly with frequency. We show that correlation experiments with the two gravitational wave detectors being built for the Laser Interferometric Gravitational Observatory (LIGO) could detect this relic radiation, for certain ranges of the parameters that characterize the underlying string cosmology model.
Geometric Transitions, Topological Strings, and Generalized Complex Geometry
Chuang, Wu-yen; /SLAC /Stanford U., Phys. Dept.
2007-06-29
Mirror symmetry is one of the most beautiful symmetries in string theory. It helps us very effectively gain insights into non-perturbative worldsheet instanton effects. It was also shown that the study of mirror symmetry for Calabi-Yau flux compactification leads us to the territory of ''Non-Kaehlerity''. In this thesis we demonstrate how to construct a new class of symplectic non-Kaehler and complex non-Kaehler string theory vacua via generalized geometric transitions. The class admits a mirror pairing by construction. From a variety of sources, including super-gravity analysis and KK reduction on SU(3) structure manifolds, we conclude that string theory connects Calabi-Yau spaces to both complex non-Kaehler and symplectic non-Kaehler manifolds and the resulting manifolds lie in generalized complex geometry. We go on to study the topological twisted models on a class of generalized complex geometry, bi-Hermitian geometry, which is the most general target space for (2, 2) world-sheet theory with non-trivial H flux turned on. We show that the usual Kaehler A and B models are generalized in a natural way. Since the gauged supergravity is the low energy effective theory for the compactifications on generalized geometries, we study the fate of flux-induced isometry gauging in N = 2 IIA and heterotic strings under non-perturbative instanton effects. Interestingly, we find we have protection mechanisms preventing the corrections to the hyper moduli spaces. Besides generalized geometries, we also discuss the possibility of new NS-NS fluxes in a new doubled formalism.
Quantum dynamics of scalar bosons in a cosmic string background
Luis B. Castro
2015-06-30
The quantum dynamics of scalar bosons embedded in the background of a cosmic string is considered. In this work, scalar bosons are described by the Duffin-Kemmer-Petiau (DKP) formalism. In particular, the effects of this topological defect in the equation of motion, energy spectrum and DKP spinor are analyzed and discussed in details. The exact solutions for the DKP oscillator in this background are presented in a closed form.
Effective Supergravity from the Weakly Coupled HeteroticString
Gaillard, Mary K.
2005-05-01
The motivation for Calabi-Yau-like compactifications of the weakly coupled E{sub 8} {circle_times} E{sub 8} heterotic string theory, its particle spectrum and the issue of dilaton stabilization are briefly reviewed. Modular invariant models for hidden sector condensation and supersymmetry breaking are described at the quantum level of the effective field theory. Their phenomenological and cosmological implications, including a possible origin for R-parity, are discussed.
Modeling coiled tubing velocity strings for gas wells
Martinez, J.; Martinez, A.
1995-12-31
Multiphase flowing pressure and velocity prediction models are necessary to coiled tubing velocity string design. A model used by most of the coiled tubing service companies or manufacturers is reviewed. Guidance is provided for selecting a coiled tubing of the proper size. The steps include: (1) Measured data matching; (2) Fluid property adjustment; (3) Pressure, velocity, and holdup selection; (4) Correlation choice; (5) Coiled tubing selection. A velocity range for the lift of liquid is given.
Hamilton-Jacobi formalism for string gas thermodynamics
Anosh Joseph; S. G. Rajeev
2009-03-27
We show that the thermodynamics of a system of strings at high energy densities under the ideal gas approximation has a formulation in terms of Hamilton-Jacobi theory. The two parameters of the system, which have dimensions of energy density and number density, respectively, define a family of hypersurfaces of co-dimension one, which can be described by the vanishing of a function F that plays the role of a Hamiltonian.
Royal, Emily
2012-05-31
The purpose of this research was to identify the main causes of light pollution from parking lot electric lighting installations and highlight the deficiencies of lighting ordinances in preventing light pollution. Using an industry-accepted lighting...
OpenGL Lighting 13. OpenGL Lighting
McDowell, Perry
OpenGL Lighting 13. OpenGL Lighting · Overview of Lighting in OpenGL In order for lighting to have an effect in OpenGL, two things are required: A light An object to be lit Lights can be set to any color determine how they reflect the light which hits them. The color(s) of an object is determined
CERN Winter School on Supergravity, Strings, and Gauge Theory 2010
None
2011-10-06
The CERN Winter School on Supergravity, Strings, and Gauge Theory is the analytic continuation of the yearly training school of the former EC-RTN string network "Constituents, Fundamental Forces and Symmetries of the Universe". The 2010 edition of the school is supported and organized by the CERN Theory Divison, and will take place from Monday January 25 to Friday January 29, at CERN. As its predecessors, this school is meant primarily for training of doctoral students and young postdoctoral researchers in recent developments in theoretical high-energy physics and string theory. The programme of the school will consist of five series of pedagogical lectures, complemented by tutorial discussion sessions in the afternoons. Previous schools in this series were organized in 2005 at SISSA in Trieste, and in 2006, 2007, 2008, and 2009 at CERN, Geneva. Other similar schools have been organized in the past by the former related RTN network "The Quantum Structure of Spacetime and the Geometric Nature of Fundamental Interactions". This edition of the school is not funded by the European Union. The school is funded by the CERN Theory Division, and the Arnold Sommerfeld Center at Ludwig-Maximilians University of Munich. Scientific committee: M. Gaberdiel, D. Luest, A. Sevrin, J. Simon, K. Stelle, S. Theisen, A. Uranga, A. Van Proeyen, E. Verlinde Local organizers: A. Uranga, J. Walcher
Thermal duality and gravitational collapse in heterotic string theories
Michael Hewitt
2015-07-04
The thermal duality of E(8) x E(8) and SO(32) heterotic string theories may underpin a mechanism that would convert the kinetic energy of infalling matter during gravitational collapse to form a region of a hot string phase that would expel gravitational gradients. This phase would be the continuation of a Ginzburg-Landau like superconductor in the Euclidean regime. In this scenario, there would be no event horizon or singularity produced in gravitational collapse. Solutions are presented for excitations of the string vacuum that may form during gravitational collapse and drive the transition to the hot phase. The proposed mechanism is developed here for the case of approximately spherical gravitational collapse in 4 uncompactified spacetime dimensions. A way to reconcile the large entropy apparently produced in this process with quantum mechanics is briefly discussed. In this scenario, astrophysical objects such as stellar or galactic cores which have undergone extreme gravitational collapse would currently be sites of an on-going conversion process to shells of this high temperature phase. The relationship of this proposal to the `firewall paradox' is noted.
Dangerous Angular KK/Glueball Relics in String Theory Cosmology
J. F. Dufaux; L. Kofman; M. Peloso
2008-07-07
The presence of Kaluza-Klein particles in the universe is a potential manifestation of string theory cosmology. In general, they can be present in the high temperature bath of the early universe. In particular examples, string theory inflation often ends with brane-antibrane annihilation followed by the energy cascading through massive closed string loops to KK modes which then decay into lighter standard model particles. However, massive KK modes in the early universe may become dangerous cosmological relics if the inner manifold contains warped throat(s) with approximate isometries. In the complimentary picture, in the AdS/CFT dual gauge theory with extra symmetries, massive glueballs of various spins become the dangerous cosmological relics. The decay of these angular KK modes/glueballs, located around the tip of the throat, is caused by isometry breaking which results from gluing the throat to the compact CY manifold. We address the problem of these angular KK particles/glueballs, studying their interactions and decay channels, from the theory side, and the resulting cosmological constraints on the warped compactification parameters, from the phenomenology side. The abundance and decay time of the long-lived non-relativistic angular KK modes depend strongly on the parameters of the warped geometry, so that observational constraints rule out a significant fraction of the parameter space. In particular, the coupling of the angular KK particles can be weaker than gravitational.
Energy-momentum correlations for Abelian Higgs cosmic strings
Daverio, David; Kunz, Martin; Lizarraga, Joanes; Urrestilla, Jon
2015-01-01
We report on the energy-momentum correlators obtained with recent numerical simulations of the Abelian Higgs model, essential for the computation of cosmic microwave background and matter perturbations of cosmic strings. Due to significant improvements both in raw computing power and in our parallel simulation framework, the dynamical range of the simulations has increased four-fold both in space and time, and for the first time we are able to simulate strings with a constant physical width in both the radiation and matter eras. The new simulations improve the accuracy of the measurements of the correlation functions at the horizon scale and confirm the shape around the peak. The normalization is slightly higher in the high wave-number tails, due to a small increase in the string density. We study for the first time the behaviour of the correlators across cosmological transitions, and discover that the correlation functions evolve adiabatically, ie the network adapts quickly to changes in the expansion rate. ...
Experiences with string matching on the Fermi Architecture
Tumeo, Antonino; Secchi, Simone; Villa, Oreste
2011-02-25
String matching is at the core of many real-world applications, such as security, bioinformatic, data mining. All these applications requires the ability to match always growing data sets against large dictionaries effectively, fastly and possibly in real time. Unfortunately, string matching is a computationally intensive procedure which poses significant challenges on current software and hardware implementations. Graphic Processing Units (GPU) have become an interesting target for such high-throughput applications, but the algorithms and the data structures need to be redesigned to be parallelized and adapted to the underlining hardware, coping with the limitations imposed by these architectures. In this paper we present an efficient implementation of the Aho-Corasick string matching algorithm on GPU, showing how we progressively redesigned the algorithm and the data structures to fit on the architecture. We then evaluate the implementation on single and multiple Tesla C2050 (T20 ``Fermi'' based) boards, comparing them to the previous Tesla C1060 (T10 based) solutions and equivalent multicore implementations on x86 CPUs. We discuss the various tradeoffs of the different architectures.
CONNECTED LIGHTING SYSTEMS MEETING
Office of Energy Efficiency and Renewable Energy (EERE)
There is a lot of buzz today about the Internet of Things and the convergence of intelligent controllable light sources, communication networks, sensors, and data exchange in future lighting...
Kevin Cahill
2011-10-10
In certain media, light has been observed with group velocities faster than the speed of light. The recent OPERA report of superluminal 17 GeV neutrinos may describe a similar phenomenon.
Kachroo, Pushkin
designated by the user, the Arduino board will dim the light to save energy. The user designates the time instance, the light is dimmed using pulse width modulation (PWM) in the Arduino's pin number 11
Automatic lighting controls demonstration
Rubinstein, F.; Verderber, R.
1990-03-01
The purpose of this work was to demonstrate, in a real building situation, the energy and peak demand reduction capabilities of an electronically ballasted lighting control system that can utilize all types of control strategies to efficiently manage lighting. The project has demonstrated that a state-of-the-art electronically ballasted dimmable lighting system can reduce energy and lighting demand by as least 50% using various combinations of control strategies. By reducing light levels over circulation areas (tuning) and reducing after hours light levels to accommodate the less stringent lighting demands of the cleaning crew (scheduling), lighting energy consumption on weekdays was reduced an average of 54% relative to the initial condition. 10 refs., 14 figs., 3 tabs.
Constraints on cosmic (super)strings from the LIGO-Virgo gravitational-wave detectors
Aasi, J; Abbott, B P; Abbott, R; Abbott, T; Abernathy, M R; Accadia, T; Acernese, F; Adams, C; Adams, T; Adhikari, R X; Affeldt, C; Agathos, M; Aggarwal, N; Aguiar, O D; Ajith, P; Allen, B; Allocca, A; Ceron, E Amador; Amariutei, D; Anderson, R A; Anderson, S B; Anderson, W G; Arai, K; Araya, M C; Arceneaux, C; Areeda, J; Ast, S; Aston, S M; Astone, P; Aufmuth, P; Aulbert, C; Austin, L; Aylott, B E; Babak, S; Baker, P T; Ballardin, G; Ballmer, S W; Barayoga, J C; Barker, D; Barnum, S H; Barone, F; Barr, B; Barsotti, L; Barsuglia, M; Barton, M A; Bartos, I; Bassiri, R; Basti, A; Batch, J; Bauchrowitz, J; Bauer, Th S; Bebronne, M; Behnke, B; Bejger, M; Beker, M G; Bell, A S; Bell, C; Belopolski, I; Bergmann, G; Berliner, J M; Bersanetti, D; Bertolini, A; Bessis, D; Betzwieser, J; Beyersdorf, P T; Bhadbhade, T; Bilenko, I A; Billingsley, G; Birch, J; Bitossi, M; Bizouard, M A; Black, E; Blackburn, J K; Blackburn, L; Blair, D; Blom, M; Bock, O; Bodiya, T P; Boer, M; Bogan, C; Bond, C; Bondu, F; Bonelli, L; Bonnand, R; Bork, R; Born, M; Boschi, V; Bose, S; Bosi, L; Bowers, J; Bradaschia, C; Brady, P R; Braginsky, V B; Branchesi, M; Brannen, C A; Brau, J E; Breyer, J; Briant, T; Bridges, D O; Brillet, A; Brinkmann, M; Brisson, V; Britzger, M; Brooks, A F; Brown, D A; Brown, D D; Brückner, F; Bulik, T; Bulten, H J; Buonanno, A; Buskulic, D; Buy, C; Byer, R L; Cadonati, L; Cagnoli, G; Bustillo, J Calderón; Calloni, E; Camp, J B; Campsie, P; Cannon, K C; Canuel, B; Cao, J; Capano, C D; Carbognani, F; Carbone, L; Caride, S; Castiglia, A; Caudill, S; Cavagliá, M; Cavalier, F; Cavalieri, R; Cella, G; Cepeda, C; Cesarini, E; Chakraborty, R; Chalermsongsak, T; Chao, S; Charlton, P; Chassande-Mottin, E; Chen, X; Chen, Y; Chincarini, A; Chiummo, A; Cho, H S; Chow, J; Christensen, N; Chu, Q; Chua, S S Y; Chung, S; Ciani, G; Clara, F; Clark, D E; Clark, J A; Cleva, F; Coccia, E; Cohadon, P -F; Colla, A; Colombini, M; Constancio, M; Conte, A; Conte, R; Cook, D; Corbitt, T R; Cordier, M; Cornish, N; Corsi, A; Costa, C A; Coughlin, M W; Coulon, J -P; Countryman, S; Couvares, P; Coward, D M; Cowart, M; Coyne, D C; Craig, K; Creighton, J D E; Creighton, T D; Crowder, S G; Cumming, A; Cunningham, L; Cuoco, E; Dahl, K; Canton, T Dal; Damjanic, M; Danilishin, S L; D'Antonio, S; Danzmann, K; Dattilo, V; Daudert, B; Daveloza, H; Davier, M; Davies, G S; Daw, E J; Day, R; Dayanga, T; De Rosa, R; Debreczeni, G; Degallaix, J; Del Pozzo, W; Deleeuw, E; Deléglise, S; Denker, T; Dent, T; Dereli, H; Dergachev, V; DeRosa, R; DeSalvo, R; Dhurandhar, S; Di Fiore, L; Di Lieto, A; Di Palma, I; Di Virgilio, A; Díaz, M; Dietz, A; Dmitry, K; Donovan, F; Dooley, K L; Doravari, S; Drago, M; Drever, R W P; Driggers, J C; Du, Z; Dumas, J -C; Dwyer, S; Eberle, T; Edwards, M; Effler, A; Ehrens, P; Eichholz, J; Eikenberry, S S; Endröczi, G; Essick, R; Etzel, T; Evans, K; Evans, M; Evans, T; Factourovich, M; Fafone, V; Fairhurst, S; Fang, Q; Farinon, S; Farr, B; Farr, W; Favata, M; Fazi, D; Fehrmann, H; Feldbaum, D; Ferrante, I; Ferrini, F; Fidecaro, F; Finn, L S; Fiori, I; Fisher, R; Flaminio, R; Foley, E; Foley, S; Forsi, E; Fotopoulos, N; Fournier, J -D; Franco, S; Frasca, S; Frasconi, F; Frede, M; Frei, M; Frei, Z; Freise, A; Frey, R; Fricke, T T; Fritschel, P; Frolov, V V; Fujimoto, M -K; Fulda, P; Fyffe, M; Gair, J; Gammaitoni, L; Garcia, J; Garufi, F; Gehrels, N; Gemme, G; Genin, E; Gennai, A; Gergely, L; Ghosh, S; Giaime, J A; Giampanis, S; Giardina, K D; Giazotto, A; Gil-Casanova, S; Gill, C; Gleason, J; Goetz, E; Goetz, R; Gondan, L; González, G; Gordon, N; Gorodetsky, M L; Gossan, S; Goßler, S; Gouaty, R; Graef, C; Graff, P B; Granata, M; Grant, A; Gras, S; Gray, C; Greenhalgh, R J S; Gretarsson, A M; Griffo, C; Groot, P; Grote, H; Grover, K; Grunewald, S; Guidi, G M; Guido, C; Gushwa, K E; Gustafson, E K; Gustafson, R; Hall, B; Hall, E; Hammer, D; Hammond, G; Hanke, M; Hanks, J; Hanna, C; Hanson, J; Harms, J; Harry, G M; Harry, I W; Harstad, E D; Hartman, M T; Haughian, K; Hayama, K; Heefner, J; Heidmann, A; Heintze, M; Heitmann, H; Hello, P; Hemming, G; Hendry, M; Heng, I S; Heptonstall, A W; Heurs, M; Hild, S; Hoak, D; Hodge, K A; Holt, K; Holtrop, M; Hong, T; Hooper, S; Horrom, T; Hosken, D J; Hough, J; Howell, E J; Hu, Y; Hua, Z; Huang, V; Huerta, E A; Hughey, B; Husa, S; Huttner, S H; Huynh, M; Huynh-Dinh, T; Iafrate, J; Ingram, D R; Inta, R; Isogai, T; Ivanov, A; Iyer, B R; Izumi, K; Jacobson, M; James, E; Jang, H; Jang, Y J; Jaranowski, P; Jiménez-Forteza, F; Johnson, W W; Jones, D; Jones, D I; Jones, R; Jonker, R J G; Ju, L; K, Haris; Kalmus, P; Kalogera, V; Kandhasamy, S; Kang, G; Kanner, J B; Kasprzack, M; Kasturi, R; Katsavounidis, E; Katzman, W; Kaufer, H; Kaufman, K; Kawabe, K; Kawamura, S; Kawazoe, F; Kéfélian, F; Keitel, D; Kelley, D B; Kells, W; Keppel, D G; Khalaidovski, A; Khalili, F Y; Khazanov, E A; Kim, B K; Kim, C; Kim, K
2013-01-01
Cosmic string cusps produce powerful bursts of gravitational waves (GWs). These bursts provide the most promising observational signature of cosmic strings. In this letter we report stringent limits on cosmic string models obtained from the analysis of 625 days of observation with the LIGO and Virgo GW detectors. A significant fraction of the cosmic string parameter space is ruled out. This result complements and improves existing limits from searches for a stochastic background of GWs using cosmic microwave background and pulsar timing data. In particular, if the size of loops is given by gravitational back-reaction, we place upper limits on the string tension $G\\mu$ below $10^{-8}$ in some regions of the cosmic string parameter space.
Constraints on cosmic strings from the LIGO-Virgo gravitational-wave detectors
J. Aasi; J. Abadie; B. P. Abbott; R. Abbott; T. Abbott; M. R. Abernathy; T. Accadia; F. Acernese; C. Adams; T. Adams; R. X. Adhikari; C. Affeldt; M. Agathos; N. Aggarwal; O. D. Aguiar; P. Ajith; B. Allen; A. Allocca; E. Amador Ceron; D. Amariutei; R. A. Anderson; S. B. Anderson; W. G. Anderson; K. Arai; M. C. Araya; C. Arceneaux; J. Areeda; S. Ast; S. M. Aston; P. Astone; P. Aufmuth; C. Aulbert; L. Austin; B. E. Aylott; S. Babak; P. T. Baker; G. Ballardin; S. W. Ballmer; J. C. Barayoga; D. Barker; S. H. Barnum; F. Barone; B. Barr; L. Barsotti; M. Barsuglia; M. A. Barton; I. Bartos; R. Bassiri; A. Basti; J. Batch; J. Bauchrowitz; Th. S. Bauer; M. Bebronne; B. Behnke; M. Bejger; M. G. Beker; A. S. Bell; C. Bell; I. Belopolski; G. Bergmann; J. M. Berliner; D. Bersanetti; A. Bertolini; D. Bessis; J. Betzwieser; P. T. Beyersdorf; T. Bhadbhade; I. A. Bilenko; G. Billingsley; J. Birch; M. Bitossi; M. A. Bizouard; E. Black; J. K. Blackburn; L. Blackburn; D. Blair; M. Blom; O. Bock; T. P. Bodiya; M. Boer; C. Bogan; C. Bond; F. Bondu; L. Bonelli; R. Bonnand; R. Bork; M. Born; V. Boschi; S. Bose; L. Bosi; J. Bowers; C. Bradaschia; P. R. Brady; V. B. Braginsky; M. Branchesi; C. A. Brannen; J. E. Brau; J. Breyer; T. Briant; D. O. Bridges; A. Brillet; M. Brinkmann; V. Brisson; M. Britzger; A. F. Brooks; D. A. Brown; D. D. Brown; F. Brückner; T. Bulik; H. J. Bulten; A. Buonanno; D. Buskulic; C. Buy; R. L. Byer; L. Cadonati; G. Cagnoli; J. Calderón Bustillo; E. Calloni; J. B. Camp; P. Campsie; K. C. Cannon; B. Canuel; J. Cao; C. D. Capano; F. Carbognani; L. Carbone; S. Caride; A. Castiglia; S. Caudill; M. Cavagliá; F. Cavalier; R. Cavalieri; G. Cella; C. Cepeda; E. Cesarini; R. Chakraborty; T. Chalermsongsak; S. Chao; P. Charlton; E. Chassande-Mottin; X. Chen; Y. Chen; A. Chincarini; A. Chiummo; H. S. Cho; J. Chow; N. Christensen; Q. Chu; S. S. Y. Chua; S. Chung; G. Ciani; F. Clara; D. E. Clark; J. A. Clark; F. Cleva; E. Coccia; P. -F. Cohadon; A. Colla; M. Colombini; M. Constancio Jr.; A. Conte; R. Conte; D. Cook; T. R. Corbitt; M. Cordier; N. Cornish; A. Corsi; C. A. Costa; M. W. Coughlin; J. -P. Coulon; S. Countryman; P. Couvares; D. M. Coward; M. Cowart; D. C. Coyne; K. Craig; J. D. E. Creighton; T. D. Creighton; S. G. Crowder; A. Cumming; L. Cunningham; E. Cuoco; K. Dahl; T. Dal Canton; M. Damjanic; S. L. Danilishin; S. D'Antonio; K. Danzmann; V. Dattilo; B. Daudert; H. Daveloza; M. Davier; G. S. Davies; E. J. Daw; R. Day; T. Dayanga; R. De Rosa; G. Debreczeni; J. Degallaix; W. Del Pozzo; E. Deleeuw; S. Deléglise; T. Denker; T. Dent; H. Dereli; V. Dergachev; R. DeRosa; R. DeSalvo; S. Dhurandhar; L. Di Fiore; A. Di Lieto; I. Di Palma; A. Di Virgilio; M. Díaz; A. Dietz; K. Dmitry; F. Donovan; K. L. Dooley; S. Doravari; M. Drago; R. W. P. Drever; J. C. Driggers; Z. Du; J. -C. Dumas; S. Dwyer; T. Eberle; M. Edwards; A. Effler; P. Ehrens; J. Eichholz; S. S. Eikenberry; G. Endröczi; R. Essick; T. Etzel; K. Evans; M. Evans; T. Evans; M. Factourovich; V. Fafone; S. Fairhurst; Q. Fang; S. Farinon; B. Farr; W. Farr; M. Favata; D. Fazi; H. Fehrmann; D. Feldbaum; I. Ferrante; F. Ferrini; F. Fidecaro; L. S. Finn; I. Fiori; R. Fisher; R. Flaminio; E. Foley; S. Foley; E. Forsi; N. Fotopoulos; J. -D. Fournier; S. Franco; S. Frasca; F. Frasconi; M. Frede; M. Frei; Z. Frei; A. Freise; R. Frey; T. T. Fricke; P. Fritschel; V. V. Frolov; M. -K. Fujimoto; P. Fulda; M. Fyffe; J. Gair; L. Gammaitoni; J. Garcia; F. Garufi; N. Gehrels; G. Gemme; E. Genin; A. Gennai; L. Gergely; S. Ghosh; J. A. Giaime; S. Giampanis; K. D. Giardina; A. Giazotto; S. Gil-Casanova; C. Gill; J. Gleason; E. Goetz; R. Goetz; L. Gondan; G. González; N. Gordon; M. L. Gorodetsky; S. Gossan; S. Goßler; R. Gouaty; C. Graef; P. B. Graff; M. Granata; A. Grant; S. Gras; C. Gray; R. J. S. Greenhalgh; A. M. Gretarsson; C. Griffo; P. Groot; H. Grote; K. Grover; S. Grunewald; G. M. Guidi; C. Guido; K. E. Gushwa; E. K. Gustafson; R. Gustafson; B. Hall; E. Hall; D. Hammer; G. Hammond; M. Hanke; J. Hanks; C. Hanna; J. Hanson; J. Harms; G. M. Harry; I. W. Harry; E. D. Harstad; M. T. Hartman; K. Haughian; K. Hayama; J. Heefner; A. Heidmann; M. Heintze; H. Heitmann; P. Hello; G. Hemming; M. Hendry; I. S. Heng; A. W. Heptonstall; M. Heurs; S. Hild; D. Hoak; K. A. Hodge; K. Holt; M. Holtrop; T. Hong; S. Hooper; T. Horrom; D. J. Hosken; J. Hough; E. J. Howell; Y. Hu; Z. Hua; V. Huang; E. A. Huerta; B. Hughey; S. Husa; S. H. Huttner; M. Huynh; T. Huynh-Dinh; J. Iafrate; D. R. Ingram; R. Inta; T. Isogai; A. Ivanov; B. R. Iyer; K. Izumi; M. Jacobson; E. James; H. Jang; Y. J. Jang; P. Jaranowski; F. Jiménez-Forteza; W. W. Johnson; D. Jones; D. I. Jones; R. Jones; R. J. G. Jonker; L. Ju; Haris K; P. Kalmus; V. Kalogera; S. Kandhasamy; G. Kang; J. B. Kanner; M. Kasprzack; R. Kasturi; E. Katsavounidis; W. Katzman; H. Kaufer; K. Kaufman; K. Kawabe; S. Kawamura; F. Kawazoe
2014-04-07
Cosmic strings can give rise to a large variety of interesting astrophysical phenomena. Among them, powerful bursts of gravitational waves (GWs) produced by cusps are a promising observational signature. In this Letter we present a search for GWs from cosmic string cusps in data collected by the LIGO and Virgo gravitational wave detectors between 2005 and 2010, with over 625 days of live time. We find no evidence of GW signals from cosmic strings. From this result, we derive new constraints on cosmic string parameters, which complement and improve existing limits from previous searches for a stochastic background of GWs from cosmic microwave background measurements and pulsar timing data. In particular, if the size of loops is given by the gravitational backreaction scale, we place upper limits on the string tension $G\\mu$ below $10^{-8}$ in some regions of the cosmic string parameter space.
Conformal Transformations and Strings for an Accelerating Quark-Antiquark Pair in AdS3
Shijong Ryang
2014-12-08
From a simple moving open string solution dual to a moving heavy quark with constant velocity in the Poincare AdS_3 spacetime, we construct an accerlerating open string solution dual to a heavy quark-antiquark pair accelerated in opposite directions by performing the three mappings such as the SL(2,R)_L x SL(2,R)_R isometry transformation, the special conformal transformation and the conformal SO(2,2) transformation. Using the string sigma model action we construct two open string solutions staying in two different regions whose dividing line is associated with the event horizon appeared on the string worldsheet and obtain the accelerating open string solution by gluing two such solutions.
Mitchell, Brian R.
2005-03-22
A portable pipe installation/removal support apparatus for assisting in the installation/removal of a series of connectable pipe strings from a ground-level borehole. The support apparatus has a base, an upright extending from the base, and, in an exemplary embodiment, a pair of catch arms extending from the upright to define a catch platform. The pair of catch arms serves to hold an upper connector end of a pipe string at an operator-convenient standing elevation by releasably catching an underside of a pipe coupler connecting two pipe strings of the series of connectable pipe strings. This enables an operator to stand upright while coupling/uncoupling the series of connectable pipe strings during the installation/removal thereof from the ground-level borehole. Additionally, a process for installing and a process for removing a series of connectable pipe strings is disclosed utilizing such a support apparatus.
Lighting and Daylight Harvesting
Bos, J.
2011-01-01
in 1992 to serve the lighting design needs of the architectural and interior design communities. With over fifty years of combined experience, our areas of expertise range from architectural and theatrical lighting to custom fixture design. Bos... Lighting Design We are active members of the International Association of Lighting Designers, the American Institute of Architects, the Illuminating Engineering Society, International Dark Skies Association and the United States Green Building Council...
Shaw-Meadow, N.
2011-01-01
kWh is the one that never gets used? ?Dedicated to making environmentally responsible products? Ringdale Introduction LED Roadway Lighting Better Light, Fewer Watts. Period. Nathan Shaw-Meadow LED Lighting Specialist Ringdale ActiveLED ESL.../exponential efficiency growth often deters investment today 7 Challenges to Implementation ESL-KT-11-11-57 CATEE 2011, Dallas, Texas, Nov. 7 ? 9, 2011 ? Municipal Street Light Case Study 8 ? Replaced 400W High Pressure Sodium fixtures with 52W Active...
Resonant acoustic transducer and driver system for a well drilling string communication system
Chanson, Gary J. (Weston, MA); Nicolson, Alexander M. (Concord, MA)
1981-01-01
The acoustic data communication system includes an acoustic transmitter and receiver wherein low frequency acoustic waves, propagating in relatively loss free manner in well drilling string piping, are efficiently coupled to the drill string and propagate at levels competitive with the levels of noise generated by drilling machinery also present in the drill string. The transmitting transducer incorporates a mass-spring piezoelectric transmitter and amplifier combination that permits self-oscillating resonant operation in the desired low frequency range.
Light emitting device comprising phosphorescent materials for white light generation
Thompson, Mark E.; Dapkus, P. Daniel
2014-07-22
The present invention relates to phosphors for energy downconversion of high energy light to generate a broadband light spectrum, which emit light of different emission wavelengths.
And the Oscar for Sustainable Mobile Lighting Goes to.... Lighting...
And the Oscar for Sustainable Mobile Lighting Goes to.... Lighting Up Operations with Hydrogen and Fuel Cell Technology And the Oscar for Sustainable Mobile Lighting Goes to.......
Five-dimensional black strings in Einstein-Gauss-Bonnet gravity
Kobayashi, Tsutomu; Tanaka, Takahiro
2005-04-15
We consider black-string-type solutions in five-dimensional Einstein-Gauss-Bonnet gravity. Numerically constructed solutions under static, axially symmetric and translationally invariant metric ansatz are presented. The solutions are specified by two asymptotic charges: mass of a black string and a scalar charge associated with the radion part of the metric. Regular black string solutions are found if and only if the two charges satisfy a fine-tuned relation, and otherwise the spacetime develops a singular event horizon or a naked singularity. We can also generate bubble solutions from the black strings by using a double Wick rotation.
U-092: Sudo Format String Bug Lets Local Users Gain Elevated Privileges
Broader source: Energy.gov [DOE]
A local user can supply a specially crafted command line argument to trigger a format string flaw and execute arbitrary commands on the target system with root privileges.
Energy Distribution of a Black Hole Solution in Heterotic String Theory
I. Radinschi
2003-02-12
We calculate the energy distribution of a charged black hole solution in heterotic string theory in the M{\\o}ller prescription.
Lighting Design | Department of Energy
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Design Lighting Design Energy-efficient indoor and outdoor lighting design focuses on ways to improve both the quality and efficiency of lighting. | Photo courtesy of...
Light extraction from organic light-emitting diodes for lighting applications by sand-blasting
Light extraction from organic light-emitting diodes for lighting applications by sand@ust.hk Abstract: Light extraction from organic light-emitting diodes (OLEDs) by scattering the light is one of the effective methods for large-area lighting applications. In this paper, we present a very simple and cost
Induction Lighting: An Old Lighting Technology Made New Again
Broader source: Energy.gov [DOE]
Induction lighting is one of the best kept secrets in energy-efficient lighting. Simply stated, induction lighting is essentially a fluorescent light without electrodes or filaments, the items that...
Lighting the Night: Technology, Urban Life and the Evolution of Street Lighting [Light in Place
Holden, Alfred
1992-01-01
Electrical 16. "Highway Lighting by So dium Vapor Lamps,"Possibilities of Street: Lighting Improve ments," TheLaunches Broad Street Lighting Promotion Campaign," The
ECE 466: LED Lighting Systems -Incandescent lightings rise and
Connors, Daniel A.
ECE 466: LED Lighting Systems - Incandescent lightings rise and demise via government policy - Alternative Fluorescent light sources and compact fluorescent lights (CFL) to incandescents - Alternative LED light sources - Color index as well as Watts to Lumens efficiency available from all three light sources
Lighting and Surfaces 11.1 Introduction to Lighting
Boyd, John P.
Chapter 11 Lighting and Surfaces 11.1 Introduction to Lighting Three-dimensional surfaces can react to light, and how computer graphics simulates this. There are three species of light (or "illumination models"): 1. Intrinsic (self-emitting) 2. Ambient light (sometimes called "diffuse light") 3
Sandia Energy - Light Creation Materials
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Light Creation Materials Home Energy Research EFRCs Solid-State Lighting Science EFRC Overview Light Creation Materials Light Creation MaterialsAlyssa Christy2015-03-26T16:28:52+00...
Arnold Schwarzenegger LIGHTING RESEARCH PROGRAM
Project Summaries ELEMENT 2: ADVANCE LIGHTING TECHNOLOGIES PROJECT 2.1 LIGHT EMITTING DIODE (LED light emitting diodes (LED) technology for general lighting applications by developing a task lamp
Efficient Aho-Corasick String Matching on Emerging Multicore Architectures
Tumeo, Antonino; Villa, Oreste; Secchi, Simone; Chavarría-Miranda, Daniel
2013-12-12
String matching algorithms are critical to several scientific fields. Beside text processing and databases, emerging applications such as DNA protein sequence analysis, data mining, information security software, antivirus, ma- chine learning, all exploit string matching algorithms [3]. All these applica- tions usually process large quantity of textual data, require high performance and/or predictable execution times. Among all the string matching algorithms, one of the most studied, especially for text processing and security applica- tions, is the Aho-Corasick algorithm. 1 2 Book title goes here Aho-Corasick is an exact, multi-pattern string matching algorithm which performs the search in a time linearly proportional to the length of the input text independently from pattern set size. However, depending on the imple- mentation, when the number of patterns increase, the memory occupation may raise drastically. In turn, this can lead to significant variability in the performance, due to the memory access times and the caching effects. This is a significant concern for many mission critical applications and modern high performance architectures. For example, security applications such as Network Intrusion Detection Systems (NIDS), must be able to scan network traffic against very large dictionaries in real time. Modern Ethernet links reach up to 10 Gbps, and malicious threats are already well over 1 million, and expo- nentially growing [28]. When performing the search, a NIDS should not slow down the network, or let network packets pass unchecked. Nevertheless, on the current state-of-the-art cache based processors, there may be a large per- formance variability when dealing with big dictionaries and inputs that have different frequencies of matching patterns. In particular, when few patterns are matched and they are all in the cache, the procedure is fast. Instead, when they are not in the cache, often because many patterns are matched and the caches are continuously thrashed, they should be retrieved from the system memory and the procedure is slowed down by the increased latency. Efficient implementations of string matching algorithms have been the fo- cus of several works, targeting Field Programmable Gate Arrays [4, 25, 15, 5], highly multi-threaded solutions like the Cray XMT [34], multicore proces- sors [19] or heterogeneous processors like the Cell Broadband Engine [35, 22]. Recently, several researchers have also started to investigate the use Graphic Processing Units (GPUs) for string matching algorithms in security applica- tions [20, 10, 32, 33]. Most of these approaches mainly focus on reaching high peak performance, or try to optimize the memory occupation, rather than looking at performance stability. However, hardware solutions supports only small dictionary sizes due to lack of memory and are difficult to customize, while platforms such as the Cell/B.E. are very complex to program.
System and method for damping vibration in a drill string
Wassell, Mark Ellsworth; Turner, William Evans; Burgess, Daniel E; Perry, Carl Allison
2014-03-04
A system for damping vibration in a drill string can include a valve assembly having a supply of a fluid, a first member, and a second member capable of moving in relation to first member in response to vibration of the drill bit. The first and second members define a first and a second chamber for holding the fluid. Fluid can flow between the first and second chambers in response to the movement of the second member in relation to the first member. The valve assembly can also include a coil or a valve for varying a resistance of the fluid to flow between the first and second chambers.
Is it really naked? On cosmic censorship in string theory
Frolov, Andrei V.
2004-11-15
We investigate the possibility of cosmic censorship violation in string theory using a characteristic double-null code, which penetrates horizons and is capable of resolving the spacetime all the way to the singularity. We perform high-resolution numerical simulations of the evolution of negative mass initial scalar field profiles, which were argued to provide a counterexample to cosmic censorship conjecture for AdS-asymptotic spacetimes in five-dimensional supergravity. In no instances formation of naked singularity is seen. Instead, numerical evidence indicates that black holes form in the collapse. Our results are consistent with earlier numerical studies, and explicitly show where the 'no black hole' argument breaks.
Is it Really Naked? On Cosmic Censorship in String Theory
Frolov, A
2004-09-30
We investigate the possibility of cosmic censorship violation in string theory using a characteristic double-null code, which penetrates horizons and is capable of resolving the spacetime all the way to the singularity. We perform high-resolution numerical simulations of the evolution of negative mass initial scalar field profiles, which were argued to provide a counter example to cosmic censorship conjecture for AdS-asymptotic spacetimes in five-dimensional supergravity. In no instances formation of naked singularity is seen. Instead, numerical evidence indicates that black holes form in the collapse. Our results are consistent with earlier numerical studies, and explicitly show where the ''no black hole'' argument breaks.
Supersymmetry Constraints and String Theory on K3
Ying-Hsuan Lin; Shu-Heng Shao; Yifan Wang; Xi Yin
2015-08-28
We study supervertices in six dimensional (2,0) supergravity theories, and derive supersymmetry non-renormalization conditions on the 4- and 6-derivative four-point couplings of tensor multiplets. As an application, we obtain exact non-perturbative results of such effective couplings in type IIB string theory compactified on K3 surface, extending previous work on type II/heterotic duality. The weak coupling limit thereof, in particular, gives certain integrated four-point functions of half-BPS operators in the nonlinear sigma model on K3 surface, that depend nontrivially on the moduli, and capture worldsheet instanton contributions.
Supersymmetry Constraints and String Theory on K3
Lin, Ying-Hsuan; Wang, Yifan; Yin, Xi
2015-01-01
We study supervertices in six dimensional (2,0) supergravity theories, and derive supersymmetry non-renormalization conditions on the 4- and 6-derivative four-point couplings of tensor multiplets. As an application, we obtain exact non-perturbative results of such effective couplings in type IIB string theory compactified on K3 surface, extending previous work on type II/heterotic duality. The weak coupling limit thereof, in particular, gives certain integrated four-point functions of half-BPS operators in the nonlinear sigma model on K3 surface, that depend nontrivially on the moduli, and capture worldsheet instanton contributions.
System and method for damping vibration in a drill string
Wassell, Mark Ellsworth (Kingwood, TX); Turner, William Evans (Durham, CT); Burgess, Daniel E. (Middletown, CT); Perry, Carl Allison (Middletown, CT)
2011-08-16
A system for damping vibration in a drill string can include a valve assembly having a supply of a fluid, a first member, and a second member capable of moving in relation to first member in response to vibration of the drill bit. The first and second members define a first and a second chamber for holding the fluid. Fluid can flow between the first and second chambers in response to the movement of the second member in relation to the first member. The valve assembly can also include a coil or a valve for varying a resistance of the fluid to flow between the first and second chambers.
System and method for damping vibration in a drill string
Wassell, Mark Ellsworth (Kingwood, TX); Turner, William Evans (Durham, CT); Burgess, Daniel E. (Middletown, CT); Perry, Carl Allison (Middletown, CT)
2008-05-27
A system for damping vibration in a drill string can include a valve assembly having a supply of a fluid, a first member, and a second member capable of moving in relation to first member in response to vibration of the drill bit. The first and second members define a first and a second chamber for holding the fluid. Fluid can flow between the first and second chambers in response to the movement of the second member in relation to the first member. The valve assembly can also include a coil or a valve for varying a resistance of the fluid to flow between the first and second chambers.
System and method for damping vibration in a drill string
Wassell, Mark Ellsworth (Kingwood, TX); Turner, William Evans (Durham, CT); Burgess, Daniel E. (Middletown, CT); Perry, Carl Allison (Middletown, CT)
2007-05-22
A system for damping vibration in a drill string can include a valve assembly having a supply of a fluid, a first member, and a second member capable of moving in relation to first member in response to vibration of the drill bit. The first and second members define a first and a second chamber for holding the fluid. Fluid can flow between the first and second chambers in response to the movement of the second member in relation to the first member. The valve assembly can also include a coil or a valve for varying a resistance of the fluid to flow between the first and second chambers.
System and method for damping vibration in a drill string
Wassell, Mark Ellsworth (Kingswood, TX); Turner, William Evans (Durham, CT); Burgess, Daniel E. (Middletown, CT); Perry, Carl Allison (Middletown, CT)
2012-08-14
A system for damping vibration in a drill string can include a valve assembly having a supply of a fluid, a first member, and a second member capable of moving in relation to first member in response to vibration of the drill bit. The first and second members define a first and a second chamber for holding the fluid. Fluid can flow between the first and second chambers in response to the movement of the second member in relation to the first member. The valve assembly can also include a coil or a valve for varying a resistance of the fluid to flow between the first and second chambers.
Size scaling of self gravitating polymers and strings
Shoichi Kawamoto; Toshihiro Matsuo
2015-06-03
We study a statistical ensemble of a single polymer with self gravitational interaction. This is a model of a gravitating string --- the precursor of a black hole. We analyze averaged sizes by mean field approximations with an effective Hamiltonian a la Edwards with Newtonian potential as well as a contact repulsive interaction. We find that there exists a certain scaling region where the attractive and the repulsive forces balance out. The repulsive interaction pushes the critical gravitational coupling to a larger value, at which the size of a polymer becomes comparable to its Schwarzschild radius, and as a result the size of the corresponding black hole increases considerably.
On higher spins and the tensionless limit of String Theory
A. Sagnotti; M. Tsulaia
2004-01-09
We discuss string spectra in the low-tension limit using the BRST formalism, with emphasis on the role of triplets of totally symmetric tensors and spinor-tensors and their generalizations to cases with mixed symmetry and to (A)dS backgrounds. We also present simple compensator forms of the field equations for individual higher-spin gauge fields that display the {unconstrained} gauge symmetry of a previous non-local construction and reduce upon partial gauge fixing to the (Fang-)Fronsdal equations. For Bose fields we also show how a local Lagrangian formulation with {unconstrained} gauge symmetry is determined by a previous BRST construction.
Size scaling of self gravitating polymers and strings
Kawamoto, Shoichi
2015-01-01
We study a statistical ensemble of a single polymer with self gravitational interaction. This is a model of a gravitating string --- the precursor of a black hole. We analyze averaged sizes by mean field approximations with an effective Hamiltonian a la Edwards with Newtonian potential as well as a contact repulsive interaction. We find that there exists a certain scaling region where the attractive and the repulsive forces balance out. The repulsive interaction pushes the critical gravitational coupling to a larger value, at which the size of a polymer becomes comparable to its Schwarzschild radius, and as a result the size of the corresponding black hole increases considerably.
High efficiency incandescent lighting
Bermel, Peter; Ilic, Ognjen; Chan, Walker R.; Musabeyoglu, Ahmet; Cukierman, Aviv Ruben; Harradon, Michael Robert; Celanovic, Ivan; Soljacic, Marin
2014-09-02
Incandescent lighting structure. The structure includes a thermal emitter that can, but does not have to, include a first photonic crystal on its surface to tailor thermal emission coupled to, in a high-view-factor geometry, a second photonic filter selected to reflect infrared radiation back to the emitter while passing visible light. This structure is highly efficient as compared to standard incandescent light bulbs.
National Synchrotron Light Source
BNL
2009-09-01
A tour of Brookhaven's National Synchrotron Light Source (NSLS), hosted by Associate Laboratory Director for Light Sources, Stephen Dierker. The NSLS is one of the world's most widely used scientific research facilities, hosting more than 2,500 guest researchers each year. The NSLS provides intense beams of infrared, ultraviolet, and x-ray light for basic and applied research in physics, chemistry, medicine, geophysics, environmental, and materials sciences.
CMB Distortions from Damping of Acoustic Waves Produced by Cosmic Strings
Hiroyuki Tashiro; Eray Sabancilar; Tanmay Vachaspati
2013-08-20
We study diffusion damping of acoustic waves in the photon-baryon fluid due to cosmic strings, and calculate the induced $\\mu$- and $y$-type spectral distortions of the cosmic microwave background. For cosmic strings with tension within current bounds, their contribution to the spectral distortions is subdominant compared to the distortions from primordial density perturbations.
The anomaly-free quantization of two-dimensional relativistic string. I
S. N. Vergeles
1998-12-21
An anomaly-free quantum theory of a relativistic string is constructed in two-dimensional space-time. The states of the string are found to be similar to the states of a massless chiral quantum particle. This result is obtained by generalizing the concept of an ``operator'' in quantum field theory.
ParsCit: An open-source CRF reference string parsing package Isaac G. Councill
Giles, C. Lee
ParsCit: An open-source CRF reference string parsing package Isaac G. Councill , C. Lee Giles , Min ParsCit, a freely available, open-source implementation of a reference string parsing package. At the core of ParsCit is a trained conditional random field (CRF) model used to label the token sequences
Physics 5B Winter 2009 Rate of Energy Transfer by Sinusoidal Waves on a String
California at Santa Cruz, University of
, Vibrations and Waves (W.W. Norton and Company, New York, 1971). First, we compute the kinetic energyPhysics 5B Winter 2009 Rate of Energy Transfer by Sinusoidal Waves on a String Consider the kinetic energy and the potential energy of this string segment due to the passage of a traveling wave
Peculiarities of String Theory on AdS(4) x CP(3)
Dmitri Sorokin; Linus Wulff
2011-03-08
We review peculiar features of type IIA string theory compactified on AdS(4) x CP(3) superspace, in particular, the structure of the Green-Schwarz action, issues with fixing its kappa-symmetry, classical integrability and the string instanton on CP(3)
Spontaneous excitation of a static atom in a thermal bath in cosmic string spacetime
Cai, Huabing; Zhou, Wenting
2015-01-01
We study the average rate of change of energy for a static atom immersed in a thermal bath of electromagnetic radiation in the cosmic string spacetime and separately calculate the contributions of thermal fluctuations and radiation reaction. We find that the transition rates are crucially dependent on the atom-string distance and polarization of the atom and they in general oscillate as the atom-string distance varies. Moreover, the atomic transition rates in the cosmic string spacetime can be larger or smaller than those in Minkowski spacetime contingent upon the atomic polarization and position. In particular, when located on the string, ground-state atoms can make a transition to excited states only if they are polarizable parallel to the string, whereas ground state atoms polarizable only perpendicular to the string are stable as if they were in a vacuum, even if they are immersed in a thermal bath. Our results suggest that the influence of a cosmic string is very similar to that of a reflecting boundary ...
Low and high frequency approximations to eigenvibrations in a string with double
Scheichl, Robert
Low and high frequency approximations to eigenvibrations in a string with double contrasts Natalia://www.bath.ac.uk/math-sci/BICS #12;Low and high frequency approximations to eigenvibrations of string with double contrasts Natalia as the order of stiffness inhomogeneity, with heavier part being softer. The limit problem for high frequency
Physics 5B Winter 2009 Rate of Energy Transfer by Sinusoidal Waves on a String
California at Santa Cruz, University of
Physics 5B Winter 2009 Rate of Energy Transfer by Sinusoidal Waves on a String Consider the kinetic energy and the potential energy of this string segment due to the passage of a traveling wave, Vibrations and Waves (W.W. Norton and Company, New York, 1971). First, we compute the kinetic energy
Robert Geroch
2010-05-10
It is argued that special relativity remains a viable physical theory even when there is permitted signals traveling faster than light.
Office of Energy Efficiency and Renewable Energy (EERE)
In this exercise, students will use a light to demonstrate the difference between being energy-efficient and energy-wasteful, and learn what energy efficiency means.
Lighting in Commercial Buildings
U.S. Energy Information Administration (EIA) Indexed Site
Illuminance Assignments for CBECS Building Activity Categories Illuminance ranges were adopted from the 1987 Illuminating Engineering Society (IES) Lighting Handbook. The IES...
Lighting in Commercial Buildings
U.S. Energy Information Administration (EIA) Indexed Site
from the engineering literature, based on CBECS building activity.) 4. Efficacy: an energy efficiency measure. Technically, the amount of light produced per unit of energy...
Lighting in Commercial Buildings
U.S. Energy Information Administration (EIA) Indexed Site
(CEC), March 1990. Advanced Lighting Technologies Application Guidelines (ALTAG), Building and Appliance Efficiency Office. 3. Dubin, F.S., Mindell, H.L., and Bloome, S., 1976....
Lighting in Commercial Buildings
U.S. Energy Information Administration (EIA) Indexed Site
energy are presented in this section. Statistics are presented by subgroups based on building characteristics, and by subgroups based on lighting equipment. The three sets of...
Edmund G. Brown Jr. LIGHTING CALIFORNIA'S FUTURE
Edmund G. Brown Jr. Governor LIGHTING CALIFORNIA'S FUTURE: SMART LIGHT-EMITTING DIODE LIGHTING's Future: Smart LightEmitting Diode Lighting in Residential Fans. California Energy Commission, PIER
Cosmic strings in hidden sectors: 1. Radiation of standard model particles
Long, Andrew J.; Hyde, Jeffrey M.; Vachaspati, Tanmay E-mail: jmhyde@asu.edu
2014-09-01
In hidden sector models with an extra U(1) gauge group, new fields can interact with the Standard Model only through gauge kinetic mixing and the Higgs portal. After the U(1) is spontaneously broken, these interactions couple the resultant cosmic strings to Standard Model particles. We calculate the spectrum of radiation emitted by these ''dark strings'' in the form of Higgs bosons, Z bosons, and Standard Model fermions assuming that string tension is above the TeV scale. We also calculate the scattering cross sections of Standard Model fermions on dark strings due to the Aharonov-Bohm interaction. These radiation and scattering calculations will be applied in a subsequent paper to study the cosmological evolution and observational signatures of dark strings.
High redshift signatures in the 21 cm forest due to cosmic string wakes
Hiroyuki Tashiro; Toyokazu Sekiguchi; Joseph Silk
2013-10-15
Cosmic strings induce minihalo formation in the early universe. The resultant minihalos cluster in string wakes and create a "21 cm forest" against the cosmic microwave background (CMB) spectrum. Such a 21 cm forest can contribute to angular fluctuations of redshifted 21 cm signals integrated along the line of sight. We calculate the root-mean-square amplitude of the 21 cm fluctuations due to strings and show that these fluctuations can dominate signals from minihalos due to primordial density fluctuations at high redshift ($z \\gtrsim 10$), even if the string tension is below the current upper bound, $G \\mu Square Kilometre Array (SKA) can potentially detect the 21 cm fluctuations due to strings with $G \\mu \\approx 7.5 \\times 10^{-8}$ for the single frequency band case and $4.0 \\times 10^{-8}$ for the multi-frequency band case.
High redshift signatures in the 21 cm forest due to cosmic string wakes
Tashiro, Hiroyuki; Sekiguchi, Toyokazu; Silk, Joseph E-mail: toyokazu.sekiguchi@nagoya-u.jp
2014-01-01
Cosmic strings induce minihalo formation in the early universe. The resultant minihalos cluster in string wakes and create a ''21 cm forest'' against the cosmic microwave background (CMB) spectrum. Such a 21 cm forest can contribute to angular fluctuations of redshifted 21 cm signals integrated along the line of sight. We calculate the root-mean-square amplitude of the 21 cm fluctuations due to strings and show that these fluctuations can dominate signals from minihalos due to primordial density fluctuations at high redshift (z?>10), even if the string tension is below the current upper bound, G? < 1.5 × 10{sup ?7}. Our results also predict that the Square Kilometre Array (SKA) can potentially detect the 21 cm fluctuations due to strings with G? ? 7.5 × 10{sup ?8} for the single frequency band case and 4.0 × 10{sup ?8} for the multi-frequency band case.
Near Flat Space limit of strings on AdS_4 x CP^3
M. Kreuzer; R. C. Rashkov; M. Schimpf
2008-11-03
The non-linear nature of string theory on non-trivial backgrounds related to the AdS/CFT correspondence suggests to look for simplifications. Two such simplifications proved to be useful in studying string theory. These are the pp-wave limit which describes point-like strings and the so called "near flat space" limit which connects two different sectors of string theory -- pp-waves and "giant magnons". Recently another example of AdS/CFT duality emerged - $AdS_4/CFT_3$, which suggests duality between $\\mathcal N=6$ CS theory and superstring theory on $AdS_4\\times \\cp$. In this paper we study the "near flat space" limit of strings on the $AdS_4\\times \\cp$ background and discuss possible applications of the reduced theory.
String Theory clues for the low-$\\ell$ CMB ?
N. Kitazawa; A. Sagnotti
2014-12-01
"Brane Supersymmetry Breaking" is a peculiar string-scale mechanism that can unpair Bose and Fermi excitations in orientifold models. It results from the simultaneous presence, in the vacuum, of collections of D-branes and orientifolds that are not mutually BPS, and is closely tied to the scale of string excitations. It also leaves behind, for a mixing of dilaton and internal breathing mode, an exponential potential that is just too steep for a scalar to emerge from the initial singularity while descending it. As a result, in this class of models the scalar can generically bounce off the exponential wall, and this dynamics brings along, in the power spectrum, an infrared depression typically followed by a pre-inflationary peak. We elaborate on a possible link between this type of bounce and the low-$\\ell$ end of the CMB angular power spectrum. For the first 32 multipoles, one can reach a 50 % reduction in $\\chi^{\\,2}$ with respect to the standard $\\Lambda$CDM setting.
Stable Non-Supersymmetric Throats in String Theory
Kachru, Shamit; Simic, Dusan; /Stanford U., ITP /SLAC /Santa Barbara, KITP; Trivedi, Sandip P.; /Tata Inst. /Stanford U., ITP /SLAC
2011-06-28
We construct a large class of non-supersymmetric AdS-like throat geometries in string theory by taking non-supersymmetric orbifolds of supersymmetric backgrounds. The scale of SUSY breaking is the AdS radius, and the dual field theory has explicitly broken supersymmetry. The large hierarchy of energy scales in these geometries is stable. We establish this by showing that the dual gauge theories do not have any relevant operators which are singlets under the global symmetries. When the geometries are embedded in a compact internal space, a large enough discrete subgroup of the global symmetries can still survive to prevent any singlet relevant operators from arising. We illustrate this by embedding one case in a non-supersymmetric orbifold of a Calabi-Yau manifold. These examples can serve as a starting point for obtaining Randall-Sundrum models in string theory, and more generally for constructing composite Higgs or technicolor-like models where strongly coupled dynamics leads to the breaking of electro-weak symmetry. Towards the end of the paper, we briefly discuss how bulk gauge fields can be incorporated by introducing D7-branes in the bulk, and also show how the strongly coupled dynamics can lead to an emergent weakly coupled gauge theory in the IR with matter fields including scalars.
Electron string ion sources for carbon ion cancer therapy accelerators
Boytsov, A Yu; Donets, E D; Donets, E E; Katagiri, K; Noda, K; Ponkin, D O; Ramzdorf, A Yu; Salnikov, V V; Shutov, V B
2015-01-01
The Electron String type of Ion Sources (ESIS) was developed, constructed and tested first in the Joint Institute for Nuclear Research. These ion sources can be the appropriate sources for production of pulsed C4+ and C6+ ion beams which can be used for cancer therapy accelerators. In fact the test ESIS Krion-6T already now at the solenoid magnetic field only 4.6 T provides more than 10^10 C4+ ions per pulse and about 5*10^9 C6+ ions per pulse. Such ion sources could be suitable for application at synchrotrons. It was also found, that Krion-6T can provide more than 10^11 C6+ ions per second at 100 Hz repetition rate, and the repetition rate can be increased at the same or larger ion output per second. This makes ESIS applicable at cyclotrons as well. As for production of 11C radioactive ion beams ESIS can be the most economic kind of ion source. To proof that the special cryogenic cell for pulse injection of gaseous species into electron string was successfully tested using the ESIS Krion-2M.
Explosively pumped laser light
Piltch, Martin S. (Los Alamos, NM); Michelotti, Roy A. (Los Alamos, NM)
1991-01-01
A single shot laser pumped by detonation of an explosive in a shell casing. The shock wave from detonation of the explosive causes a rare gas to luminesce. The high intensity light from the gas enters a lasing medium, which thereafter outputs a pulse of laser light to disable optical sensors and personnel.
Rushford, Michael C. (Livermore, CA)
1990-01-01
In a system for recording images having vastly differing light intensities over the face of the image, a light intensity compressor is provided that utilizes the properties of twisted nematic liquid crystals to compress the image intensity. A photoconductor or photodiode material that is responsive to the wavelength of radiation being recorded is placed adjacent a layer of twisted nematic liquid crystal material. An electric potential applied to a pair of electrodes that are disposed outside of the liquid crystal/photoconductor arrangement to provide an electric field in the vicinity of the liquid crystal material. The electrodes are substantially transparent to the form of radiation being recorded. A pair of crossed polarizers are provided on opposite sides of the liquid crystal. The front polarizer linearly polarizes the light, while the back polarizer cooperates with the front polarizer and the liquid crystal material to compress the intensity of a viewed scene. Light incident upon the intensity compressor activates the photoconductor in proportion to the intensity of the light, thereby varying the field applied to the liquid crystal. The increased field causes the liquid crystal to have less of a twisting effect on the incident linearly polarized light, which will cause an increased percentage of the light to be absorbed by the back polarizer. The intensity of an image may be compressed by forming an image on the light intensity compressor.
Lighting affects appearance LightSource emits photons
Jacobs, David
1 Lighting affects appearance #12;2 LightSource emits photons Photons travel in a straight line). And then some reach the eye/camera. #12;3 Reflectance Model how objects reflect light. Model light sources Algorithms for computing Shading: computing intensities within polygons Determine what light strikes what
VIRTUAL LIGHT: DIGITALLY-GENERATED LIGHTING FOR VIDEO CONFERENCING APPLICATIONS
Greenberg, Albert
VIRTUAL LIGHT: DIGITALLY-GENERATED LIGHTING FOR VIDEO CONFERENCING APPLICATIONS Andrea Basso method to improve the lighting conditions of a real scene or video sequence. In particular we concentrate on modifying real light sources intensities and inserting virtual lights into a real scene viewed from a fixed
LightBox -Exploring Interaction Modalities with Colored Light
of light to very subtle animations, transitions and dimmed lighting effects. Implementation LightBox is housed in an aluminum suitcase measuring 48x38x25cm. The lid of the suitcase contains a panel of 12x12 Design. Figure 1. An animated lighting sequence visualized on the hi-power LEDs of LightBox #12
Indoor positioning algorithm using light-emitting diode visible light
Kavehrad, Mohsen
Indoor positioning algorithm using light- emitting diode visible light communications Zhou Zhou of Use: http://spiedl.org/terms #12;Indoor positioning algorithm using light-emitting diode visible light. This paper proposes a novel indoor positioning algorithm using visible light communications (VLC
Hartman, C W; Reisman, D B; McLean, H S; Thomas, J
2007-05-30
A fusion reactor is described in which a moving string of mutually repelling compact toruses (alternating helicity, unidirectional Btheta) is generated by repetitive injection using a magnetized coaxial gun driven by continuous gun current with alternating poloidal field. An injected CT relaxes to a minimum magnetic energy equilibrium, moves into a compression cone, and enters a conducting cylinder where the plasma is heated to fusion-producing temperature. The CT then passes into a blanketed region where fusion energy is produced and, on emergence from the fusion region, the CT undergoes controlled expansion in an exit cone where an alternating poloidal field opens the flux surfaces to directly recover the CT magnetic energy as current which is returned to the formation gun. The CT String Reactor (CTSTR) reactor satisfies all the necessary MHD stability requirements and is based on extrapolation of experimentally achieved formation, stability, and plasma confinement. It is supported by extensive 2D, MHD calculations. CTSTR employs minimal external fields supplied by normal conductors, and can produce high fusion power density with uniform wall loading. The geometric simplicity of CTSTR acts to minimize initial and maintenance costs, including periodic replacement of the reactor first wall.
White light velocity interferometer
Erskine, D.J.
1999-06-08
The invention is a technique that allows the use of broadband and incoherent illumination. Although denoted white light velocimetry, this principle can be applied to any wave phenomenon. For the first time, powerful, compact or inexpensive sources can be used for remote target velocimetry. These include flash and arc lamps, light from detonations, pulsed lasers, chirped frequency lasers, and lasers operating simultaneously in several wavelengths. The technique is demonstrated with white light from an incandescent source to measure a target moving at 16 m/s. 41 figs.
Scharf, John Edward (Oldsmar, FL)
1998-11-03
A reflectance pulse oximeter that determines oxygen saturation of hemoglobin using two sources of electromagnetic radiation in the green optical region, which provides the maximum reflectance pulsation spectrum. The use of green light allows placement of an oximetry probe at central body sites (e.g., wrist, thigh, abdomen, forehead, scalp, and back). Preferably, the two green light sources alternately emit light at 560 nm and 577 nm, respectively, which gives the biggest difference in hemoglobin extinction coefficients between deoxyhemoglobin, RHb, and oxyhemoglobin, HbO.sub.2.
Lakeview Light and Power- Commercial Lighting Rebate Program
Broader source: Energy.gov [DOE]
Lakeview Light and Power offers a commercial lighting rebate program. Rebates apply to the installation of energy efficient lighting retrofits in non-residential buildings. The rebate program is...
Demonstration Assessment of Light-Emitting Diode (LED) Roadway Lighting
None
2009-11-01
A U.S. Department of Energy Solid-State Lighting Gateway Report on a Demonstration Assessment of Light-Emitting Diode (LED) Roadway Lighting in Lija Loop, Portland, Oregon.
Z2 electric strings and center vortices in SU(2) lattice gauge theory
M. I. Polikarpov; P. V. Buividovich
2008-01-01
We study the representations of SU(2) lattice gauge theory in terms of sums over the worldsheets of center vortices and Z2 electric strings, i.e. surfaces which open on the Wilson loop. It is shown that in contrast to center vortices the density of electric Z2 strings diverges in the continuum limit of the theory independently of the gauge fixing, however, their contribution to the Wilson loop yields physical string tension due to non-positivity of their statistical weight in the path integral, which is in turn related to the presence of Z2 topological monopoles in the theory.
Sustainability of multi-field inflation and bound on string scale
Jinn-Ouk Gong
2009-02-11
We study the effects of the interaction terms between the inflaton fields on the inflationary dynamics in multi-field models. With power law type potential and interactions, the total number of e-folds may get considerably reduced and can lead to unacceptably short period of inflation. Also we point out that this can place a bound on the characteristic scale of the underlying theory such as string theory. Using a simple multi-field chaotic inflation model from string theory, the string scale is constrained to be larger than the scale of grand unified theory.
Power-law Behavior of High Energy String Scatterings in Compact Spaces
Jen-Chi Lee; Yi Yang
2007-09-28
We calculate high energy massive scattering amplitudes of closed bosonic string compactified on the torus. We obtain infinite linear relations among high energy scattering amplitudes. For some kinematic regimes, we discover that some linear relations break down and, simultaneously, the amplitudes enhance to power-law behavior due to the space-time T-duality symmetry in the compact direction. This result is consistent with the coexistence of the linear relations and the softer exponential fall-off behavior of high energy string scattering amplitudes as we pointed out prevously. It is also reminiscent of hard (power-law) string scatterings in warped spacetime proposed by Polchinski and Strassler.
C. Pajares; D. Sousa; R. A. Vázquez
2000-05-31
At high gluon or string densities, gluons' saturation or the strong interaction among strings, either forming colour ropes or giving rise to string's percolation, induces a strong suppression in the particle multiplicities produced at high energy. This suppression implies important modifications on cosmic ray shower development. In particular, it is shown that it affects the depth of maximum, the elongation rate, and the behaviour of the number of muons at energies around 10^{17}-10^{18} eV. The existing cosmic ray data point out in the same direction.
Wave and quantum properties of peptide strings: defining a helix in spacetime
Razvan Tudor Radulescu
2009-04-25
Previous studies have described the concept of peptide strings in qualitative terms and illustrated it by applying its corrolaries in order to elucidate basic questions in oncology and rheumatology. The present investigation is the first to quantify these potential sub- and transcellular phenomena. Accordingly, the propagation of peptide strings is proposed here to occur by way of waves that in turn are subject to the energy equation established by Planck. As a result of these insights, widespread future applications can now be envisaged for peptide strings both in molecular medicine and quantum optics.
Columbia Water & Light- HVAC and Lighting Efficiency Rebates
Broader source: Energy.gov [DOE]
Columbia Water & Light (CWL) offers rebates to its commercial and industrial customers for the purchase of high efficiency HVAC installations and efficient lighting. Incentives for certain...
Peninsula Light Company- Commercial Efficient Lighting Rebate Program
Broader source: Energy.gov [DOE]
Peninsula Light Company (PLC) offers a rebate program for commercial customers who wish to upgrade to energy efficient lighting. Participating customers must be served by PLC commercial service....
Alexander Milov
2008-12-21
This article reviews the current status of experimental results obtained in the measurement of light vector mesons produced in proton-proton and heavy ion collisions at different energies. The review is focused on two phenomena related to the light vector mesons; the modification of the spectral shape in search of Chiral symmetry restoration and suppression of the meson production in heavy ion collisions. The experimental results show that the spectral shape of light vector mesons are modified compared to the parameters measured in vacuum. The nature and the magnitude of the modification depends on the energy density of the media in which they are produced. The suppression patterns of light vector mesons are different from the measurements of other mesons and baryons. The mechanisms responsible for the suppression of the mesons are not yet understood. Systematic comparison of existing experimental results points to the missing data which may help to resolve the problem.
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
lamp produces about 1750 lumens. Footcandle: a lumen of light distributed over a 1-square-foot (0.09-square-meter) area. Ideal Illumination: the minimum number of footcandles...
Solid State Lighting Reliability
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Solid State Lighting Reliability 2015Building Technologies Office Peer Review Lynn Davis, PhD RTI International ldavis@rti.org --- 919-316-3325 Project Summary Timeline: Start...
Horn, Berthold K.P.
This is a random collection of facts about radiant and luminous energy. Some of this information may be useful in the design of photo-diode image sensors, in the set-up of lighting for television microscopes and the ...
National Synchrotron Light Source
None
2010-01-08
A tour of Brookhaven's National Synchrotron Light Source (NSLS). The NSLS is one of the world's most widely used scientific research facilities, hosting more than 2,500 guest researchers each year. The NSLS provides intense beams of infrared, ultraviole
Lighting in Commercial Buildings
U.S. Energy Information Administration (EIA) Indexed Site
5.2 152.6 160.5 54.6 Assembly Health Care Lodging Office 0 20 40 60 80 100 120 140 160 180 Energy Information Administration Energy Consumption Series: Lighting in Commercial...
Implications of fast radio bursts for superconducting cosmic strings
Yun-Wei Yu; Kwong-Sang Cheng; Gary Shiu; Henry Tye
2014-11-06
Highly beamed, short-duration electromagnetic bursts could be produced by superconducting cosmic string (SCS) loops oscillating in cosmic magnetic fields. We demonstrated that the basic characteristics of SCS bursts such as the electromagnetic frequency and the energy release could be consistently exhibited in the recently discovered fast radio bursts (FRBs). Moreover, it is first showed that the redshift distribution of the FRBs can also be well accounted for by the SCS burst model. Such agreements between the FRBs and SCS bursts suggest that the FRBs could originate from SCS bursts and thus they could provide an effective probe to study SCSs. The obtained values of model parameters indicate that the loops generating the FRBs have a small length scale and they are mostly formed in the radiation-dominated cosmological epoch.
Nonreciprocal wave scattering on nonlinear string-coupled oscillators
Stefano Lepri; Arkady Pikovsky
2014-10-29
We study scattering of a periodic wave in a string on two lumped oscillators attached to it. The equations can be represented as a driven (by the incident wave) dissipative (due to radiation losses) system of delay differential equations of neutral type. Nonlinearity of oscillators makes the scattering non-reciprocal: the same wave is transmitted differently in two directions. Periodic regimes of scattering are analysed approximately, using amplitude equation approach. We show that this setup can act as a nonreciprocal modulator via Hopf bifurcations of the steady solutions. Numerical simulations of the full system reveal nontrivial regimes of quasiperiodic and chaotic scattering. Moreover, a regime of a "chaotic diode", where transmission is periodic in one direction and chaotic in the opposite one, is reported.
CP Violation and Dilaton Stabilization in Heterotic String Models
S. Khalil; O. Lebedev; S. Morris
2002-04-26
We study the possibility of spontaneous CP violation in string models with the dilaton field stabilized at a phenomenologically acceptable value. We consider three mechanisms to stabilize the dilaton: multiple gaugino condensates, a nonperturbative Kahler potential, and a superpotential based on S-duality, and analyze consequent CP phases in the soft SUSY breaking terms. Due to non-universality forced upon the theory by requiring a non-trivial CKM phase, the EDM problem becomes more severe. Even if there are no complex phases in the VEVs of the SUSY breaking fields, the electric dipole moments are overproduced by orders of magnitude. We also address the question of modular invariance of the physical CP phases.
CP Violation and Dilaton Stabilization in Heterotic String Models
Khalil, S; Morris, S
2002-01-01
We study the possibility of spontaneous CP violation in string models with the dilaton field stabilized at a phenomenologically acceptable value. We consider three mechanisms to stabilize the dilaton: multiple gaugino condensates, a nonperturbative Kahler potential, and a superpotential based on S-duality, and analyze consequent CP phases in the soft SUSY breaking terms. Due to non-universality forced upon the theory by requiring a non-trivial CKM phase, the EDM problem becomes more severe. Even if there are no complex phases in the VEVs of the SUSY breaking fields, the electric dipole moments are overproduced by orders of magnitude. We also address the question of modular invariance of the physical CP phases.
Implications of fast radio bursts for superconducting cosmic strings
Yu, Yun-Wei; Cheng, Kwong-Sang; Shiu, Gary; Tye, Henry E-mail: hrspksc@hku.hk E-mail: iastye@ust.hk
2014-11-01
Highly beamed, short-duration electromagnetic bursts could be produced by superconducting cosmic string (SCS) loops oscillating in cosmic magnetic fields. We demonstrated that the basic characteristics of SCS bursts such as the electromagnetic frequency and the energy release could be consistently exhibited in the recently discovered fast radio bursts (FRBs). Moreover, it is first showed that the redshift distribution of the FRBs can also be well accounted for by the SCS burst model. Such agreements between the FRBs and SCS bursts suggest that the FRBs could originate from SCS bursts and thus they could provide an effective probe to study SCSs. The obtained values of model parameters indicate that the loops generating the FRBs have a small length scale and they are mostly formed in the radiation-dominated cosmological epoch.
Nonreciprocal wave scattering on nonlinear string-coupled oscillators
Lepri, Stefano; Pikovsky, Arkady
2014-12-01
We study scattering of a periodic wave in a string on two lumped oscillators attached to it. The equations can be represented as a driven (by the incident wave) dissipative (due to radiation losses) system of delay differential equations of neutral type. Nonlinearity of oscillators makes the scattering non-reciprocal: The same wave is transmitted differently in two directions. Periodic regimes of scattering are analyzed approximately, using amplitude equation approach. We show that this setup can act as a nonreciprocal modulator via Hopf bifurcations of the steady solutions. Numerical simulations of the full system reveal nontrivial regimes of quasiperiodic and chaotic scattering. Moreover, a regime of a “chaotic diode,” where transmission is periodic in one direction and chaotic in the opposite one, is reported.
Birth of the Universe from the Landscape of String Theory
Archil Kobakhidze; Laura Mersini-Houghton
2004-10-20
We show that a unique, most probable and stable solution for the wavefunction of the universe, with a very small cosmological constant $\\Lambda_1 \\simeq (\\frac{\\pi}{l_p N})^2$, can be predicted from the supersymmetric minisuperspace with $N$ vacua, of the landscape of string theory without reffering to the antropic principle. Due to the nearest neighbor tunneling in moduli space lattice, the $N$-fold degeneracy of vacua is lifted and a discrete spectrum of bound state levels over the whole minisuperspace emerges. $SUSY$ is spontaneously broken by these bound states, with discrete nonzero energy levels $\\Lambda_s \\simeq (\\frac{s \\pi}{l_p N})^2$, $s = 1,2,..$.
Size scaling of self gravitating polymers and strings
Shoichi Kawamoto; Toshihiro Matsuo
2015-08-04
We study a statistical ensemble of a single polymer with self gravitational interaction. This is a model of a gravitating string --- the precursor of a black hole. We analyze averaged sizes by mean field approximations with an effective Hamiltonian a la Edwards with Newtonian potential as well as a contact repulsive interaction. We find that there exists a certain scaling region where the attractive and the repulsive forces balance out. The repulsive interaction pushes the critical gravitational coupling to a larger value, at which the size of a polymer becomes comparable to its Schwarzschild radius, and as a result the size of the corresponding black hole increases considerably. We show phase diagrams in various dimensions that clarify how the size changes as the strengths of repulsive and gravitational forces vary.
Solid state lighting component
Yuan, Thomas; Keller, Bernd; Ibbetson, James; Tarsa, Eric; Negley, Gerald
2010-10-26
An LED component comprising an array of LED chips mounted on a planar surface of a submount with the LED chips capable of emitting light in response to an electrical signal. The LED chips comprise respective groups emitting at different colors of light, with each of the groups interconnected in a series circuit. A lens is included over the LED chips. Other embodiments can comprise thermal spreading structures included integral to the submount and arranged to dissipate heat from the LED chips.
Solid state lighting component
Keller, Bernd; Ibbetson, James; Tarsa, Eric; Negley, Gerald; Yuan, Thomas
2012-07-10
An LED component comprising an array of LED chips mounted on a planar surface of a submount with the LED chips capable of emitting light in response to an electrical signal. The LED chips comprise respective groups emitting at different colors of light, with each of the groups interconnected in a series circuit. A lens is included over the LED chips. Other embodiments can comprise thermal spreading structures included integral to the submount and arranged to dissipate heat from the LED chips.
Light and Plants Plants use light to photosynthesize. Name two places that light can come from
Koptur, Suzanne
Light and Plants Plants use light to photosynthesize. Name two places that light can come from: 1 (CO2, a gas) from the air and turn it into SUGARS (food). This process is powered by energy from light plants) for energy. Photosynthetically Active Radiation (PAR) is a combination of red light and blue
Strings on AdS Wormholes and Nonsingular Black Holes
H. Lu; Justin F. Vazquez-Poritz; Zhibai Zhang
2014-10-22
Certain AdS black holes in the STU model can be conformally scaled to wormhole and black hole solutions of an f(R) type theory which have two asymptotically AdS regions and are completely free of curvature singularities. While there is a delta-function source for the dilaton, classical string probes are not sensitive to this singularity. If the AdS/CFT correspondence can be applied in this context, then the wormhole background describes a phase in which two copies of a conformal field theory interact with each other, whereas the nonsingular black hole describes entangled states. By studying the behavior of open strings on these backgrounds, we extract a number of features of the quarks and anti-quarks that live in the field theories. In the interacting phase, we find that there is a maximum speed with which the quarks can move without losing energy, beyond which energy is transferred from a quark in one field theory to a quark in the other. We also compute the rate at which moving quarks within entangled states lose energy to the two surrounding plasmas. While a quark-antiquark pair within a single field theory exhibits Coulomb interaction for small separation, a quark in one field theory exhibits spring-like confinement with an anti-quark in the other field theory. For the entangled states, we study how the quark-antiquark screening length depends on temperature and chemical potential. In the interacting phase of the two field theories, a quadruplet made up of one quark-antiquark pair in each field theory can undergo transitions involving how the quarks and antiquarks are paired in terms of the screening.
LED Lighting | Department of Energy
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
focusing light in ways that are useful in homes and commercial settings. The light-emitting diode (LED) is one of today's most energy-efficient and rapidly-developing lighting...
Energy Conservation in Industrial Lighting
Meharg, E.
1979-01-01
were identified. Savings in power and cost were quantified for typical examples as follows: Task lighting, high light source efficacy, high luminaire mounting height, efficient luminaires, surroundings painted a light color, regular luminaire cleaning...
Higher order light propagation volumes
Martin, Timothy Ly; Martin, Timothy Ly
2012-01-01
1.1 Introduction . . . . . . . . . 1.2 Light Propagation4.1.1 Injection of Virtual Point Lights and Geometryof the Stanford bunny, lit by an area light, rendered using
Lingampalli, Nithya
2013-01-01
S. (1991). Meridians conduct light. Moskow: Raum and Zeit.the bod’ys absorption of light. Explore, 9(2), doi: https://01). The healing use of light and color. Health Care Design
Christensen, M.
1981-01-01
A discussion of the cost of light and how it relates to the cost of people. The new Illuminating Engineering Society recommended method of determining lighting levels will be explained. Also several ways of providing good lighting to increase...
New Light Sources for Tomorrow's Lighting Designs
Krailo, D. A.
1986-01-01
and lighting systems. Table 2 shows the development of four-foot energy-saving retrofit lamps. By utilizing new cathode designed and different gas fills, 34-watt energy-saving lamps were developed that operate on existing rapid start ballasts and afford... of fluorescent lamps, two watts of system power are consumed in heating the lamp cath odes. The shedding of cathode heating wattage was the next lamp efficiency improvement to be introduced. One available sy tern dis connects the lamp cathodes from...
Lighting Design | Department of Energy
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
as part of your whole-house design -- an approach for building an energy-efficient home. Indoor Lighting Design When designing indoor lighting for energy efficiency,...
GATEWAY Demonstrations: LED Street Lighting
Cook, Tyson; Shackelford, Jordan; Pang, Terrance Pang
2008-12-01
This report summarizes an assessment project conducted to study the performance of light emitting diode (LED) luminaires in a street lighting application in San Francisco, CA.
Interior Lighting Efficiency for Municipalities
Broader source: Energy.gov [DOE]
This webinar covered a basic understanding of lighting, different types of lamps and luminaries, importance of energy efficiency in lighting, and knowledge of where to find financial resources.
2010 US Lighting Market Characterization
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
2010 U.S. Lighting Market Characterization January 2012 Prepared for: Solid-State Lighting Program Building Technologies Program Office of Energy Efficiency and Renewable Energy...
Lighting Controls | Department of Energy
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
fluorescent lighting fixtures rather than replace them. Dimmers and LEDs Some light-emitting diode (LED) lightbulbs can be used with dimmers. LED bulbs and fixtures must be...
Constraints on Cosmic Strings from the LIGO-Virgo Gravitational-Wave Detectors
Aggarwal, Nancy
Cosmic strings can give rise to a large variety of interesting astrophysical phenomena. Among them, powerful bursts of gravitational waves (GWs) produced by cusps are a promising observational signature. In this Letter we ...
Exact solutions of a two-dimensional Kemmer oscillator in the gravitational field of cosmic string
Nadjette. Messai; Abdelmalek. Boumali
2015-04-21
The two dimensional Kemmer oscillator under the influence of the gravitational field produced by a topology such as the cosmic string spacetime and in the presence of a uniform magnetic field as well as without magnetic field are investigated.
Constant-Time Word-Size String-Matching D. Breslauer, L. Gasienec, R. Grossi
Lonardi, Stefano
= 00010101 10010101 1010 1010 1010 #12;Experiments in SMART [FSTTCS11] Intel Sandy Bridge, SSE (Streaming SIMD Extension), AVX (Advanced Vector Extension) SMART (String MAtching Research Tool) by Faro
Anselma, Luca
An algorithm to compute fingering for string instruments Daniele P. Radicioni*, Luca Anselma) modelling the constraints posed by body-instrument interaction (operational), iv) manipulating sound the interaction between the performer and the instrument, and manipulating sound parameters accordingly
Metamaterials Mimicking Dynamic Spacetime, D-brane and Noncommutativity in String Theory
Rong-Xin Miao; Rui Zheng; Miao Li
2011-02-03
We propose an executable scheme to mimic the expanding cosmos in 1+2 dimensions in laboratory. Furthermore, we develop a general procedure to use nonlinear metamaterials to mimic D-brane and noncommutativity in string theory.
Mechanism of the Cassie-Wenzel transition via the atomistic and continuum string methods
Alberto Giacomello; Simone Meloni; Marcus Mueller; Carlo Massimo Casciola
2014-11-17
The string method is a general and flexible strategy to compute the most probable transition path for an activated process (rare event). We apply here the atomistic string method in the density field to the Cassie-Wenzel transition, a central problem in the field of superhydrophobicity. We discuss in detail the mechanism of wetting of a submerged hydrophobic cavity of nanometer size and its dependence on the geometry of the cavity. Furthermore, we discuss the algorithmic analogies between the string method and CREaM [Giacomello et al., Phys. Rev. Lett. 109, 226102 (2012)], a method inspired by the string that allows for a faster and simpler computation of the mechanism and of the free-energy profiles of the wetting process. This approach is general and can be employed in mesoscale and macroscopic calculations.
Three-Charge Black Holes and Quarter BPS States in Little String Theory
Giveon, Amit; Kutasov, David; Lee, Sungjay
2015-01-01
We show that the system of $k$ NS5-branes wrapping $\\mathbb{T}^4\\times S^1$ has non-trivial vacuum structure. Different vacua have different spectra of 1/4 BPS states that carry momentum and winding around the $S^1$. In one vacuum, such states are described by black holes; in another, they can be thought of as perturbative BPS states in Double Scaled Little String Theory. In general, both kinds of states are present. We compute the degeneracy of perturbative BPS states exactly, and show that it differs from that of the corresponding black holes. We comment on the implication of our results to the black hole microstate program, UV/IR mixing in Little String Theory, string thermodynamics, the string/black hole transition, and other issues.
Dienes, Keith R; Dienes, Keith R.; Lennek, Michael
2007-01-01
The realization that string theory gives rise to a huge landscape of vacuum solutions has recently prompted a statistical approach towards extracting phenomenological predictions from string theory. Unfortunately, for most classes of string models, direct enumeration of all solutions is not computationally feasible and thus statistical studies must resort to other methods in order to extract meaningful information. In this paper, we discuss some of the issues that arise when attempting to extract statistical correlations from a large data set to which our computational access is necessarily limited. Our main focus is the problem of ``floating correlations''. As we discuss, this problem is endemic to investigations of this type and reflects the fact that not all physically distinct string models are equally likely to be sampled in any random search through the landscape, thereby causing statistical correlations to ``float'' as a function of sample size. We propose several possible methods that can be used to o...
From gauge-string duality to strong interactions: a Pedestrian's Guide
Steven S. Gubser; Andreas Karch
2009-05-27
We survey recent progress in understanding the relation of string theory to quantum chromodynamics, focusing on holographic models of gauge theories similar to QCD and applications to heavy-ion collisions.
The Effective String of 3D Gauge Systems at the Deconfining Transition
M. Caselle; F. Gliozzi
1991-10-01
It is argued that the effective string of whatever 3D gauge system at the deconfining transition is universally described by the minimal $N=2$ extended superconformal theory at $c=1$. A universal value of the critical temperature is predicted.
Lighting affects appearance LightSource emits photons
Jacobs, David
1 Lighting affects appearance #12;2 LightSource emits photons Photons travel in a straight line). And then some reach the eye/camera. #12;3 Basic fact: Light is linear Double intensity of sources, double photons reaching eye. Turn on two lights, and photons reaching eye are same as sum of number when each
Quasi light fields: extending the light field to coherent radiation
Wornell, Gregory W.
Quasi light fields: extending the light field to coherent radiation Anthony Accardi1,2 and Gregory light field, and for coherent radiation using electromagnetic field theory. We present a model of coherent image formation that strikes a balance between the utility of the light field
Interior Light Level Measurements Appendix F -Interior Light Level Measurements
Appendix F Interior Light Level Measurements #12;F.1 Appendix F - Interior Light Level. A potential concern is that a lower VT glazing may increase electric lighting use to compensate for lost qualify and quantify a representative loss of daylighting, and therefore electric lighting use
Demonstration Assessment of LED Roadway Lighting: Philadelphia...
Office of Scientific and Technical Information (OSTI)
LED Roadway Lighting: Philadelphia, PA Royer, Michael P.; Tuenge, Jason R.; Poplawski, Michael E. Roadway Lighting; Solid-state lighting; LED lighting; SSL; LED; GATEWAY Roadway...
Lighting Principles and Terms | Department of Energy
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Principles and Terms Lighting Principles and Terms Light quantity, energy consumption, and light quality are the basic principles of lighting. | Photo courtesy of
Testimonials - Partnerships in LED Lighting - Philips Lumileds...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
LED Lighting - Philips Lumileds Lighting, LLC Testimonials - Partnerships in LED Lighting - Philips Lumileds Lighting, LLC Addthis An error occurred. Try watching this video on...
Methods and systems for determining angular orientation of a drill string
Cobern, Martin E. (Cheshire, CT)
2010-03-23
Preferred methods and systems generate a control input based on a periodically-varying characteristic associated with the rotation of a drill string. The periodically varying characteristic can be correlated with the magnetic tool face and gravity tool face of a rotating component of the drill string, so that the control input can be used to initiate a response in the rotating component as a function of gravity tool face.
Can a self-gravitating thin cosmic string obey the Nambu-Goto dynamics ?
B. Boisseau; C. Charmousis; B. Linet
1997-10-14
We assume that a self-gravitating string is locally described by a thin tube of matter represented by a ``smoothed conical metric''. If we impose a specific constraint on the model of string then its central line obeys the Nambu-Goto dynamics in the limit where the radius of the tube tends to zero. If no constraint is added then the world sheet of the central line is totally geodesic.
Entropy of Warped Taub-NUT AdS Black String via the Brick Wall Method
Chong Oh Lee
2015-03-10
When we consider five-dimensional warped Taub-NUT/bolt AdS black string with minimally coupled massive scalar field, we calculate entropies by using the brick wall method. It is found that they are proportional to being quadratically divergent in a cutoff parameter. In particular, we show that the entropy of warped Taub-NUT AdS black string holds for an area law in the bulk as well as on the brane.
Multiple orthogonal polynomials, string equations and the large-n limit
L. Martinez Alonso; E. Medina
2008-12-30
The Riemann-Hilbert problems for multiple orthogonal polynomials of types I and II are used to derive string equations associated to pairs of Lax-Orlov operators. A method for determining the quasiclassical limit of string equations in the phase space of the Whitham hierarchy of dispersionless integrable systems is provided. Applications to the analysis of the large-n limit of multiple orthogonal polynomials and their associated random matrix ensembles and models of non-intersecting Brownian motions are given.
Qi Liu; Norman H. Christ; Chulwoo Jung
2012-06-01
We present a systematic study of the effectiveness of light quark mass reweighting. This method allows a single lattice QCD ensemble, generated with a specific value of the dynamical light quark mass, to be used to determine results for other, nearby light dynamical quark masses. We study two gauge field ensembles generated with 2+1 flavors of dynamical domain wall fermions with light quark masses m_l=0.02 (m_\\pi=620 MeV) and m_l=0.01 (m_\\pi=420 MeV). We reweight each ensemble to determine results which could be computed directly from the other and check the consistency of the reweighted results with the direct results. The large difference between the 0.02 and 0.01 light quark masses suggests that this is an aggressive application of reweighting as can be seen from fluctuations in the magnitude of the reweighting factor by four orders of magnitude. Never-the-less, a comparison of the reweighed topological charge, average plaquette, residual mass, pion mass, pion decay constant, and scalar correlator between these two ensembles shows agreement well described by the statistical errors. The issues of the effective number of configurations and finite sample size bias are discussed. An examination of the topological charge distribution implies that it is more favorable to reweight from heavier mass to lighter quark mass.
M. Sadegh Movahed; Shahram Khosravi
2011-03-01
In this paper we study the footprint of cosmic string as the topological defects in the very early universe on the cosmic microwave background radiation. We develop the method of level crossing analysis in the context of the well-known Kaiser-Stebbins phenomenon for exploring the signature of cosmic strings. We simulate a Gaussian map by using the best fit parameter given by WMAP-7 and then superimpose cosmic strings effects on it as an incoherent and active fluctuations. In order to investigate the capability of our method to detect the cosmic strings for the various values of tension, $G\\mu$, a simulated pure Gaussian map is compared with that of including cosmic strings. Based on the level crossing analysis, the superimposed cosmic string with $G\\mu\\gtrsim 4\\times 10^{-9}$ in the simulated map without instrumental noise and the resolution $R=1'$ could be detected. In the presence of anticipated instrumental noise the lower bound increases just up to $G\\mu\\gtrsim 5.8\\times 10^{-9}$.
Semiclassical Strings in Electric and Magnetic Fields Deformed $AdS_5 \\times S^5$ Spacetimes
Wung-Hong Huang
2006-01-06
We first apply the transformation of mixing azimuthal and internal coordinate or mixing time and internal coordinate to the 11D M-theory with a stack N M2-branes to find the spacetime of a stack of N D2-branes with magnetic or electric flux in 10 D IIA string theory, after the Kaluza-Klein reduction. We then perform the T duality to the spacetime to find the background of a stack of N D3-branes with magnetic or electric flux. In the near-horizon limit the background becomes the magnetic or electric field deformed $AdS_5 \\times S^5$. We adopt an ansatz to find the classical string solution which is rotating in the deformed $S^5$ with three angular momenta in the three rotation planes. The relations between the classical string energy and its angular momenta are found and results show that the external magnetic and electric fluxes will increase the string energy. Therefore, from the AdS/CFT point of view, the corrections of the anomalous dimensions of operators in the dual SYM theory will be positive. We also investigate the small fluctuations in these solutions and discuss the effects of magnetic and electric fields on the stability of these classical rotating string solutions. Finally, we find the possible solutions of string pulsating on the deformed spacetimes and show that the corrections to the anomalous dimensions of operators in the dual SYM theory are non-negative.
TeV Scale Strings and Scattering Amplitudes at the LHC
Dean Carmi
2015-08-16
We study aspects of TeV string scale models of intersecting D-branes. The gauge bosons arise from strings ending on stacks of D-branes, whereas chiral matter arises from strings stretched between intersecting D-branes. Our focus is on scattering amplitudes (at tree-level), Regge states (string excitations), and collider phenomenology. Achieving a low string scale is possible in models of Large extra dimensions. At the LHC, a low enough string scale implies that cross sections will deviate from their standard model predictions. Moreover, Regge states as well as Kaluza-Klein states and winding states may be produced. In a large class of intersecting D-brane models, the quark-gluon amplitudes with at most 2 quarks turn out to be independent of the geometry of the extra dimensions. Therefore these type of amplitudes, which we call "universal amplitudes", are model independent. The universal amplitudes involve exchanges of Regge states only, whereas amplitudes with more then 2 quarks also involve exchanges of KK and winding states. The main computational part of this work is concerned with suggesting methods to calculate the decay widths of the Regge states, and with the formalism for treating amplitudes containing exchanges of higher spin particles.
Cosmic strings in $f\\left(R,L_m\\right)$ gravity
Tiberiu Harko; Matthew J. Lake
2015-09-27
We consider Kasner-type static, cylindrically symmetric interior string solutions in the $f\\left(R,L_m\\right)$ theory of modified gravity. The physical properties of the string are described by an anisotropic energy-momentum tensor satisfying the condition $T_t^t=T_z^z$; that is, the energy density of the string along the $z$-axis is equal to minus the string tension. As a first step in our study we obtain the gravitational field equations in the $f\\left(R,L_m\\right)$ theory for a general static, cylindrically symmetric metric, and then for a Kasner-type metric, in which the metric tensor components have a power law dependence on the radial coordinate $r$. String solutions in two particular modified gravity models are investigated in detail. The first is the so-called "exponential" modified gravity, in which the gravitational action is proportional to the exponential of the sum of the Ricci scalar and matter Lagrangian, and the second is the "self-consistent model", obtained by explicitly determining the gravitational action from the field equations under the assumption of a power law dependent matter Lagrangian. In each case, the thermodynamic parameters of the string, as well as the precise form of the matter Lagrangian, are explicitly obtained.
Glennys R. Farrar
1997-07-25
Not yet. ALEPH's recent exclusion limit employs an aggressive determination of theoretical uncertainties using a simplified application of the Bayesian method. The validity of their analysis can be evaluated by its further implications, such as contradicting the existence a b quark and requiring relations between hadronic event-shape observables which are not observed. Traditional error estimation methods result in a much larger estimate for the theoretical uncertainties. This puts the ALEPH and also Csikor-Fodor limits at the $\\sim 1~ \\sigma$ level for the very light gluino scenario. A recent astrophysical result implies direct searches will be more difficult than previously anticipated, adding to the importance of reducing the QCD uncertainty in predictions sensitive to indirect effects of light gluinos. Some possible indications in favor of a light gluino are noted.
Lindsey, Jonathan S. (Raleigh, NC)
2002-01-01
A light harvesting array useful for the manufacture of devices such as solar cells comprises: (a) a first substrate comprising a first electrode; and (b) a layer of light harvesting rods electrically coupled to the first electrode, each of the light harvesting rods comprising a polymer of Formula I: X.sup.1.paren open-st.X.sup.m+1).sub.m (I) wherein m is at least 1, and may be from two, three or four to 20 or more; X.sup.1 is a charge separation group (and preferably a porphyrinic macrocycle, which may be one ligand of a double-decker sandwich compound) having an excited-state of energy equal to or lower than that of X.sup.2, and X.sup.2 through X.sup.m+1 are chromophores (and again are preferably porphyrinic macrocycles).
Pupillary efficient lighting system
Berman, Samuel M. (San Francisco, CA); Jewett, Don L. (Mill Valley, CA)
1991-01-01
A lighting system having at least two independent lighting subsystems each with a different ratio of scotopic illumination to photopic illumination. The radiant energy in the visible region of the spectrum of the lighting subsystems can be adjusted relative to each other so that the total scotopic illumination of the combined system and the total photopic illumination of the combined system can be varied independently. The dilation or contraction of the pupil of an eye is controlled by the level of scotopic illumination and because the scotopic and photopic illumination can be separately controlled, the system allows the pupil size to be varied independently of the level of photopic illumination. Hence, the vision process can be improved for a given level of photopic illumination.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Eifert, Till; Nachman, Benjamin
2015-02-20
A light supersymmetric top quark partner (stop) with a mass nearly degenerate with that of the standard model (SM) top quark can evade direct searches. The precise measurement of SM top properties such as the cross-section has been suggested to give a handle for this ‘stealth stop’ scenario. We present an estimate of the potential impact a light stop may have on top quark mass measurements. The results indicate that certain light stop models may induce a bias of up to a few GeV, and that this effect can hide the shift in, and hence sensitivity from, cross-section measurements. Duemore »to the different initial states, the size of the bias is slightly different between the LHC and the Tevatron. The studies make some simplifying assumptions for the top quark measurement technique, and are based on truth-level samples.« less
Valentine, Paul; Edwards, Doreen D.; Walker, Jr., William John; Slack, Lyle H.; Brown, Wayne Douglas; Osborne, Cathy; Norton, Michael; Begley, Richard
2010-05-18
A light-emitting ceramic based panel, hereafter termed "electroceramescent" panel, is herein claimed. The electroceramescent panel is formed on a substrate providing mechanical support as well as serving as the base electrode for the device. One or more semiconductive ceramic layers directly overlay the substrate, and electrical conductivity and ionic diffusion are controlled. Light emitting regions overlay the semiconductive ceramic layers, and said regions consist sequentially of a layer of a ceramic insulation layer and an electroluminescent layer, comprised of doped phosphors or the equivalent. One or more conductive top electrode layers having optically transmissive areas overlay the light emitting regions, and a multi-layered top barrier cover comprising one or more optically transmissive non-combustible insulation layers overlay said top electrode regions.
Radioluminescent lighting technology
Not Available
1990-01-01
The glow-in-the-dark stereotype that characterizes the popular image of nuclear materials is not accidental. When the French scientist, Henri Becquerel, first discovered radioactivity in 1896, he was interested in luminescence. Radioluminescence, the production of light from a mixture of energetic and passive materials, is probably the oldest practical application of the unstable nucleus. Tritium-based radioluminescent lighting, in spite of the biologically favorable character of the gaseous tritium isotope, was included in the general tightening of environmental and safety regulations. Tritium light manufacturers would have to meet two fundamental conditions: (1) The benefit clearly outweighed the risk, to the extent that even the perceived risk of a skeptical public would be overcome. (2) The need was significant enough that the customer/user would be willing and able to afford the cost of regulation that was imposed both in the manufacture, use and eventual disposal of nuclear materials. In 1981, researchers at Oak Ridge National Laboratory were investigating larger radioluminescent applications using byproduct nuclear material such as krypton-85, as well as tritium. By 1982, it appeared that large source, (100 Curies or more) tritium gas tube, lights might be useful for marking runways and drop zones for military operations and perhaps even special civilian aviation applications. The successful development of this idea depended on making the light bright enough and demonstrating that large gas tube sources could be used and maintained safely in the environment. This successful DOE program is now in the process of being completed and closed-out. Working closely with the tritium light industry, State governments and other Federal agencies, the basic program goals have been achieved. This is a detailed report of what they have learned, proven, and discovered. 91 refs., 29 figs., 5 tabs. (JF)
van der Mark, M B
2015-01-01
Einstein's relativity theory appears to be very accurate, but at times equally puzzling. On the one hand, electromagnetic radiation must have zero rest mass in order to propagate at the speed of light, but on the other hand, since it definitely carries momentum and energy, it has non-zero inertial mass. Hence, by the principle of equivalence, it must have non-zero gravitational mass, and so, light must be heavy. In this paper, no new results will be derived, but a possibly surprising perspective on the above paradox is given.
Hastbacka, Mildred; Dieckmann, John; Bouza, Antonio
2013-03-30
The article discusses solid state lighting technologies. This topic was covered in two previous ASHRAE Journal columns (2010). This article covers advancements in technologies and the associated efficacies. The life-cycle, energy savings and market potential of these technologies are addressed as well.
Belavin, Alexander
2015-01-01
The fermionic NSR string possesses a hidden N = 2 superconformal algebra on the world-sheet. In this work, we show how to use an isomorphism of this algebra, the so-called spectral flow, for construction of a subspace of physical states of the string, on which space-time supersymmetry acts. This construction is an alternative to the GSO-projection in string theory.
Keep Foodborne Illness from Spoiling Holiday Parties
Nutrition, Food and
2008-12-17
and after handling food, especially raw meat or poultry. ? Make sure the utensils and food-preparation areas, including countertops and cutting boards, are clean. Wash them with soap and hot water after each use. ? After each cleaning, sanitize... water and then sanitize them after each use. ? Never place cooked food on a plate that has held raw meat, poultry, fish, or seafood unless the plate has been washed thoroughly with hot, soapy water. Cook food products to safe internal temperatures...
A Factsheet on Holiday Fire Prevention
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion Batteries Print Lithium-ion batteriesAyou|ach year fires
Code of Conduct regarding holiday gifts
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room News PublicationsAuditsCluster Compatibility Mode Cluster CompatibilityCoalCode of Conduct
Fourth Friday Cancelled due to Thanksgiving Holidays
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverse (Journal Article)Forthcoming Upgrades to the ARMD. Westphal, B.Fourth
New Year's Holiday Hours - December 30, 2015
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformationJessework usesofPublications64 2.251 2.211New SpeciesNew UserTraining
Coiled tubing velocity string hangoff method and apparatus
Gipson, T.C.
1991-07-02
This patent describes a method for hanging off a coiled tube velocity string in an active gas production well tubing run, the run having at least a master valve and a first line valve. It includes installing a hangoff assembly in the production well tubing run between the master valve and the first line valve the hangoff assembly comprising a hangoff head, a second line valve, an upper valve, and a hydraulic packoff valve, the hangoff head further comprising a threaded body member, a slip bowl and a threaded cap; inserting through the hydraulic packoff valve, the upper valve, and the hangoff head, coiled tubing for fluid communication with well gases and fluids in the production well tubing run, the coiled tubing having a first downhole end being open to immediately receive and conduct the gases and fluids; opening gas and fluid communication between the production well tubing run and the open end of the coiled tubing whereby the well gases and fluid may pass up through the coiled tubing, the hangoff head sealing the gases and fluids from passing to the hydraulic packoff valve, the upper valve and the second line valve; further inserting the coiled tubing to a desired depth in the production well tubing run; and rotating the cap of the hangoff head to expose the slip bowl.
Demonstration Assessment of Light-Emitting Diode Roadway Lighting...
Office of Scientific and Technical Information (OSTI)
New York Citation Details In-Document Search Title: Demonstration Assessment of Light-Emitting Diode Roadway Lighting on the FDR Drive in New York, New York This a report about a...
Light Dance : light and the nature of body movement
Riskin, Seth
1989-01-01
Light Dance is a conscious transfiguration of the body, its movement and the encompassing space; a transposition of matter to light exalted in the dance. This corresponds to the conceptualized spirit of the performer whose ...
Making fuel from light: Argonne research sheds light on photosynthesis...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Making fuel from light: Argonne research sheds light on photosynthesis and creation of solar fuel By Jo Napolitano * September 1, 2015 Tweet EmailPrint Refined by nature over a...
Pappas, Daniel S. (Los Alamos, NM)
1989-01-01
Apparatus is provided for generating energy in the form of light radiation. A fusion reactor is provided for generating a long, or continuous, pulse of high-energy neutrons. The neutron flux is coupled directly with the lasing medium. The lasing medium includes a first component selected from Group O of the periodic table of the elements and having a high inelastic scattering cross section. Gamma radiation from the inelastic scattering reactions interacts with the first component to excite the first component, which decays by photon emission at a first output wavelength. The first output wavelength may be shifted to a second output wavelength using a second liquid component responsive to the first output wavelength. The light outputs may be converted to a coherent laser output by incorporating conventional optics adjacent the laser medium.
Quaglioni, S; Navratil, P; Roth, R
2009-12-15
The exact treatment of nuclei starting from the constituent nucleons and the fundamental interactions among them has been a long-standing goal in nuclear physics. Above all nuclear scattering and reactions, which require the solution of the many-body quantum-mechanical problem in the continuum, represent an extraordinary theoretical as well as computational challenge for ab initio approaches.We present a new ab initio many-body approach which derives from the combination of the ab initio no-core shell model with the resonating-group method [4]. By complementing a microscopic cluster technique with the use of realistic interactions, and a microscopic and consistent description of the nucleon clusters, this approach is capable of describing simultaneously both bound and scattering states in light nuclei. We will discuss applications to neutron and proton scattering on sand light p-shell nuclei using realistic nucleon-nucleon potentials, and outline the progress toward the treatment of more complex reactions.
Anil Duggal; Don Foust; Chris Heller; Bill Nealon; Larry Turner; Joe Shiang; Nick Baynes; Tim Butler; Nalin Patel
2004-02-29
The goal of this program was to reduce the long term technical risks that were keeping the lighting industry from embracing and developing organic light-emitting diode (OLED) technology for general illumination. The specific goal was to develop OLEDs for lighting to the point where it was possible to demonstrate a large area white light panel with brightness and light quality comparable to a fluorescence source and with an efficacy comparable to that of an incandescent source. it was recognized that achieving this would require significant advances in three area: (1) the improvement of white light quality for illumination, (2) the improvement of OLED energy efficiency at high brightness, and (3) the development of cost-effective large area fabrication techniques. The program was organized such that, each year, a ''deliverable'' device would be fabricated which demonstrated progress in one or more of the three critical research areas. In the first year (2001), effort concentrated on developing an OLED capable of generating high illumination-quality white light. Ultimately, a down-conversion method where a blue OLED was coupled with various down-conversion layers was chosen. Various color and scattering models were developed to aid in material development and device optimization. The first year utilized this approach to deliver a 1 inch x 1 inch OLED with higher illumination-quality than available fluorescent sources. A picture of this device is shown and performance metrics are listed. To their knowledge, this was the first demonstration of true illumination-quality light from an OLED. During the second year, effort concentrated on developing a scalable approach to large area devices. A novel device architecture consisting of dividing the device area into smaller elements that are monolithically connected in series was developed. In the course of this development, it was realized that, in addition to being scalable, this approach made the device tolerant to the most common OLED defect--electrical shorts. This architecture enabled the fabrication of a 6 inch x 6 inch OLED deliverable for 2002. A picture of this deliverable is shown and the performance metrics are listed. At the time, this was the highest efficiency, highest lumen output illumination-quality OLED in existence. The third year effort concentrated on improving the fabrication yield of the 6 inch x 6 inch devices and improving the underlying blue device efficiency. An efficiency breakthrough was achieved through the invention of a new device structure such that now 15 lumen per watt devices could be fabricated. A 2 feet x 2 feet OLED panel consisting of sixteen 6 inch x 6 inch high efficiency devices tiled together was then fabricated. Pictures of this panel are shown with performance metrics listed. This panel met all project objectives and was the final deliverable for the project. It is now the highest efficiency, highest lumen output, illumination-quality OLED in existence.
Solid State Lighting Reliability
Office of Energy Efficiency and Renewable Energy (EERE) 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 Center Home Page on Delicious RankADVANCED MANUFACTURINGEnergy BillsNo.Hydrogen4EnergySolid State Lighting Reliability 2014 Building
Hagedorn String Thermodynamics in Curved Spacetimes and near Black Hole Horizons
Thomas G. Mertens
2015-06-25
This thesis concerns the study of high-temperature string theory on curved backgrounds, generalizing the notions of Hagedorn temperature and thermal scalar to general backgrounds. Chapter 2 contains a review on string thermodynamics in flat space, setting the stage. Chapters 3 and 4 contain the detailed study of the random walk picture in a general curved background. Chapters 5 and 6 then apply this to Rindler space, the near-horizon approximation of a generic (uncharged) black hole. Chapters 7 and 8 contain a study of the AdS3 and BTZ WZW models where we study the thermal spectrum and the resulting random walk picture that emerges. Chapters 9 and 10 attempt to draw general conclusions from the study of the two specific examples earlier: we draw lessons on string thermodynamics in general and on (perturbative) string thermodynamics around black hole horizons. For the latter, we point out a possible link to the firewall paradox. Finally, chapter 11 contains a detailed discussion on the near-Hagedorn (and high-energy) stress tensor in a generic spacetime, the results of which are applied to provide a description of the Bekenstein-Hawking entropy in terms of long string equilibration.
LED Lighting | Department of Energy
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
are directional, focusing light in ways that are useful in homes and commercial settings. The light-emitting diode (LED) is one of today's most energy-efficient and...
An International Year of Light
Faure, Claudie
of light-based technologies for the equitable development of global society. The project received, renewable energy and energy efficiency, and for PROSPECTUS An International Year of Light Science Technology Nature Culture Development
Photodetector with enhanced light absorption
Kane, James (Lawrenceville, NJ)
1985-01-01
A photodetector including a light transmissive electrically conducting layer having a textured surface with a semiconductor body thereon. This layer traps incident light thereby enhancing the absorption of light by the semiconductor body. A photodetector comprising a textured light transmissive electrically conducting layer of SnO.sub.2 and a body of hydrogenated amorphous silicon has a conversion efficiency about fifty percent greater than that of comparative cells. The invention also includes a method of fabricating the photodetector of the invention.
Webinar: Fuel Cell Mobile Lighting
Broader source: Energy.gov [DOE]
Video recording of the Fuel Cell Technologies Office webinar, Fuel Cell Mobile Lighting, originally presented on November 13, 2012.
Faster than Light Quantum Communication
A. Y. Shiekh
2008-04-05
Faster than light communication might be possible using the collapse of the quantum wave-function without any accompanying paradoxes.
Lighting and Dark Sky Regulations
Radcliffe, David
Lighting and Dark Sky Regulations Marjorie Palmer Spring 2008 #12;The UGA Land Use Clinic provides Road, Room 101 Athens, GA 30602-1510 (706) 583-0373 · Fax (706) 583-0612 jroskie@uga.edu #12;Lighting......................................................................................................................................1 II. Approaches to Lighting Regulation
The 21 cm Signature of Shock Heated and Diffuse Cosmic String Wakes
Oscar F. Hernandez; Robert H. Brandenberger
2012-07-31
The analysis of the 21 cm signature of cosmic string wakes is extended in several ways. First we consider the constraints on $G\\mu$ from the absorption signal of shock heated wakes laid down much later than matter radiation equality. Secondly we analyze the signal of diffuse wake, that is those wakes in which there is a baryon overdensity but which have not shock heated. Finally we compare the size of these signals compared to the expected thermal noise per pixel which dominates over the background cosmic gas brightness temperature and find that the cosmic string signal will exceed the thermal noise of an individual pixel in the Square Kilometre Array for string tensions $G\\mu > 2.5 \\times 10^{-8}$.
Coiled tubing velocity string set at record 20,500 ft
Adams, L.S. )
1992-04-13
This paper reports that coiled tubing, set at record depth, significantly reduced costs and posed lower mechanical failure risk for recompleting a gas well in the Delaware basin of West Texas. Alternative completions such as replacing the existing tubing string with smaller diameter conventional API production tubing was deemed less economical and effective. The gas well, George M. Shelton No. 2, was recompleted on July 18, 1991, by Chevron U.S.A. Production Co. The gas is produced from the deep, low-pressure Ellenburger formation in the Gomez field. The hang-off depth of 20,500 ft set a world record for the deepest permanently installed coiled tubing. The 1-1/2 in. coiled tubing velocity string, run within the existing 4-1/2 and 4-in. tapered production tubing string, consists of seven segments that vary in wall thickness from 0.087 to 0.156 in.
High Redshift Gamma-Ray Bursts: Observational Signatures of Superconducting Cosmic Strings?
K. S. Cheng; Yun-Wei Yu; T. Harko
2010-06-11
The high-redshift gamma-ray bursts (GRBs), GRBs 080913 and 090423, challenge the conventional GRB progenitor models by their short durations, typical for short GRBs, and their high energy releases, typical for long GRBs. Meanwhile, the GRB rate inferred from high-redshift GRBs also remarkably exceeds the prediction of the collapsar model, with an ordinary star formation history. We show that all these contradictions could be eliminated naturally, if we ascribe some high-redshift GRBs to electromagnetic bursts of superconducting cosmic strings. High-redshift GRBs could become a reasonable way to test the superconducting cosmic string model, because the event rate of cosmic string bursts increases rapidly with increasing redshifts, whereas the collapsar rate decreases.
The 21 cm signature of shock heated and diffuse cosmic string wakes
Hernández, Oscar F.; Brandenberger, Robert H. E-mail: rhb@physics.mcgill.ca
2012-07-01
The analysis of the 21 cm signature of cosmic string wakes is extended in several ways. First we consider the constraints on G? from the absorption signal of shock heated wakes laid down much later than matter radiation equality. Secondly we analyze the signal of diffuse wake, that is those wakes in which there is a baryon overdensity but which have not shock heated. Finally we compare the size of these signals to the expected thermal noise per pixel which dominates over the background cosmic gas brightness temperature and find that the cosmic string signal will exceed the thermal noise of an individual pixel in the Square Kilometre Array for string tensions G? > 2.5 × 10{sup ?8}.