National Nuclear Security Administration (NNSA)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports to3,1,50022,3,,0,,6,1,Separation 23Tribal EnergyCatalytic Coby Mods 002, 006, 020,holidayCFRTheSeismicity of8/%2A en Office of
Today LED Holiday Lights, Tomorrow the World?
Gordon, Kelly L.
2004-12-20T23:59:59.000Z
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
Office of Environmental Management (EM)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports to3,1,50022,3,,0,,6,1,Separation 23 362 334Department ofEnergy FY 2014GinaFuel Shortages Homeowners: Respond toHotEnergyDo Holiday
Save Money with LED Holiday Light Strings | Department of Energy
Broader source: Energy.gov (indexed) [DOE]
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports to3,1,50022,3,,0,,6,1,Separation 23 362Transmission:portion5When purchasing plug-inreportASNRDepartment of EnergyWork
Twist Field as Three String Interaction Vertex in Light Cone String Field Theory
Isao Kishimoto; Sanefumi Moriyama; Shunsuke Teraguchi
2007-03-22T23:59:59.000Z
It has been suggested that matrix string theory and light-cone string field theory are closely related. In this paper, we investigate the relation between the twist field, which represents string interactions in matrix string theory, and the three-string interaction vertex in light-cone string field theory carefully. We find that the three-string interaction vertex can reproduce some of the most important OPEs satisfied by the twist field.
Light superconducting strings in the Galaxy
Francesc Ferrer; Tanmay Vachaspati
2006-08-08T23:59:59.000Z
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.
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.
2014-07-28T23:59:59.000Z
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
2015-03-04T23:59:59.000Z
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
2015-01-01T23:59:59.000Z
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...
Proton Stability, Gauge Coupling Unification and a Light $Z^\\prime$ in Heterotic-string Models
Alon E. Faraggi; Viraf M. Mehta
2013-06-11T23:59:59.000Z
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.
EECBG Success Story: South Carolina Community Lights Up the Season...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
South Carolina Community Lights Up the Season with Energy-Efficient Holiday Lights EECBG Success Story: South Carolina Community Lights Up the Season with Energy-Efficient Holiday...
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,...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journalhttp://www.fnal.gov/directorate/nalcal/nalcal02_07_05_files/nalcal.gif Directorate - Events - FermilabHoliday Schedule NERSC Holiday
Leveraging Holidays and Other Events | Department of Energy
Office of Environmental Management (EM)
Leveraging Holidays and Other Events Leveraging Holidays and Other Events Better Buildings Residential Network Driving Demand Peer Exchange Call Series: Leveraging Holidays and...
They're Here! Winter, Holidays, and the New Year. How Will You...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Photo courtesy of iStockphoto.comAvailableLight It's Finally Time to Think about the Holidays End of Summer Check Up: How Did You Do? This Month on Energy Savers: December 2011...
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-...
holiday | National Nuclear Security Administration
National Nuclear Security Administration (NNSA)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports to3,1,50022,3,,0,,6,1,Separation 23Tribal EnergyCatalytic Coby Mods 002, 006, 020,holiday | National Nuclear Security Administration
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journal Article)41clothThe Bonneville Power AdministrationHawaiiEnergyFloridaOutlookOctoberHeavytheHighlyHobart namedvacuum vessel
Proton Stability and Light $Z^\\prime$ Inspired by String Derived Models
Alon E. Faraggi; Viraf M. Mehta
2011-06-15T23:59:59.000Z
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.
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
EECBG Success Story: North Pole's Holiday Wish for an Energy...
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...
Your Holidays ... Brought to You by Fuel Cells | Department of...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Your Holidays ... Brought to You by Fuel Cells Your Holidays ... Brought to You by Fuel Cells December 19, 2013 - 11:44am Addthis Fuel cells, which work like batteries but...
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
Sales Tax Holiday for Energy-Efficient Appliances
Broader source: Energy.gov [DOE]
In November 2007, Maryland enacted legislation creating a sales and use tax "holiday" for certain energy-efficient appliances, beginning in 2011. Under the law, qualifying appliances purchased...
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.
SEP Success Story: Solar Field Powers Historic Garden Holiday...
States, and a popular attraction for elaborate holiday decorations, is now running on solar power thanks to help from the Energy Department. Learn more. Addthis Related...
Museum Closed for New Year's Holiday
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journal Article)41clothThe Bonneville PowerTariff Pages default SignEnergy4 3.4 MyriamEnergyMuseum Closed for New Year's Holiday Museum
Keep Foodborne Illness from Spoiling Holiday Parties
Nutrition, Food and
2008-12-17T23:59:59.000Z
degrees F Pork (all cuts): 160 degrees F Ground beef, veal and lamb: 160 degrees F Poultry (whole, ground, or parts): 165 degrees F Egg dishes: 160 degrees F Fish: 145 degrees F After the foods are prepared, make sure they are served soon or kept at 140... degrees F or higher so bacteria don?t have a chance to grow. If you are serving foods to holiday guests buffet-style, plate up extra serving platters and dishes ahead of time and keep them in a hot oven (set at 200 to 250 degrees F). As the food...
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 DeliciousPlasma | Department of EnergyBrakingDepartment of Energyal.Energy KlamathLANL990E|LDVFrequentlyLED
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 DeliciousPlasma | Department of EnergyBrakingDepartment of Energyal.Energy
Bachas, C.
1986-03-01T23:59:59.000Z
This is an elementary introduction to the classical and quantum mechanics of a single bosonic string, and to some aspects of its supersymmetric and heterotic extensions. 22 refs.
Summing Planar Bosonic Open Strings
Bardakci, Korkut
2006-02-16T23:59:59.000Z
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.
Observed Holiday Aerosol Reduction and Temperature Cooling over East Asia
Gong, Daoyi; Wang, Wenshan; Qian, Yun; Bai, Wenbing; Guo, Yuanxi; Mao, Rui
2014-06-16T23:59:59.000Z
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.
String bit models for superstring
Bergman, O.; Thorn, C.B.
1995-12-31T23:59:59.000Z
The authors extend the model of string as a polymer of string bits to the case of superstring. They mainly concentrate on type II-B superstring, with some discussion of the obstacles presented by not II-B superstring, together with possible strategies for surmounting them. As with previous work on bosonic string work within the light-cone gauge. The bit model possesses a good deal less symmetry than the continuous string theory. For one thing, the bit model is formulated as a Galilei invariant theory in (D {minus} 2) + 1 dimensional space-time. This means that Poincare invariance is reduced to the Galilei subgroup in D {minus} 2 space dimensions. Naturally the supersymmetry present in the bit model is likewise dramatically reduced. Continuous string can arise in the bit models with the formation of infinitely long polymers of string bits. Under the right circumstances (at the critical dimension) these polymers can behave as string moving in D dimensional space-time enjoying the full N = 2 Poincare supersymmetric dynamics of type II-B superstring.
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
Florida, University of
Tax Information Publication - 2014 New Energy Star and WaterSense Products Sales Tax Holiday 1 2014 Sales Tax Holiday for New Energy Star and WaterSense Products September 19 through September 21, 2014 on the first $1,500 of the sales price of a new qualifying Energy Star or WaterSense product. The exemption
Add to your Holiday menu: "Canap ", a glass of punch during cocktail hour
Add to your Holiday menu: "Canapé ", a glass of punch during cocktail hour and ½ of bottle of wine per person For only $27.00 per person
Holiday Gifts for Energy Efficiency | Department of Energy
Office of Environmental Management (EM)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports to3,1,50022,3,,0,,6,1,Separation 23 362 334Department ofEnergy FY 2014Gina McCarthyUnclassifiedHeat(JuneInformation -HistoryHoliday
Holiday Heights, New Jersey: Energy Resources | Open Energy Information
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousPlasmaP aCentrothermDepew, NewAl.,HardinHelios EnergyInformation Hobo Pool PoolHolderness,Holiday Heights,
G. L. Alberghi
2010-02-19T23:59:59.000Z
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
2013-05-21T23:59:59.000Z
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
2013-06-02T23:59:59.000Z
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.
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journal Article)41clothThe Bonneville PowerTariff Pages default Sign InCenter (LMI-EFRC) Hotel & Travel TheLighting Sign In About |
Washington Taylor
2006-06-28T23:59:59.000Z
This elementary introduction to string field theory highlights the features and the limitations of this approach to quantum gravity as it is currently understood. String field theory is a formulation of string theory as a field theory in space-time with an infinite number of massive fields. Although existing constructions of string field theory require expanding around a fixed choice of space-time background, the theory is in principle background-independent, in the sense that different backgrounds can be realized as different field configurations in the theory. String field theory is the only string formalism developed so far which, in principle, has the potential to systematically address questions involving multiple asymptotically distinct string backgrounds. Thus, although it is not yet well defined as a quantum theory, string field theory may eventually be helpful for understanding questions related to cosmology in string theory.
Memorial Day Weekend Sales Tax Holiday for Energy-Efficient Products
Broader source: Energy.gov [DOE]
Purchases of certain energy-efficient products during Memorial Day weekend are exempt from the state sales and use tax.* This amounts to a three-day tax holiday beginning on the Saturday preceding...
Excitation Fields in a Superconducting Global String
J. R. Morris
1995-09-28T23:59:59.000Z
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, D.K.; Kuhns, D.J.; Wiersholm, O.; Miller, T.A.
1993-03-02T23:59:59.000Z
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.
Neil. D. Lambert; David Tong
1999-07-13T23:59:59.000Z
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.
Non-linear sigma-models and string theories
Sen, A.
1986-10-01T23:59:59.000Z
The connection between sigma-models and string theories is discussed, as well as how the sigma-models can be used as tools to prove various results in string theories. Closed bosonic string theory in the light cone gauge is very briefly introduced. Then, closed bosonic string theory in the presence of massless background fields is discussed. The light cone gauge is used, and it is shown that in order to obtain a Lorentz invariant theory, the string theory in the presence of background fields must be described by a two-dimensional conformally invariant theory. The resulting constraints on the background fields are found to be the equations of motion of the string theory. The analysis is extended to the case of the heterotic string theory and the superstring theory in the presence of the massless background fields. It is then shown how to use these results to obtain nontrivial solutions to the string field equations. Another application of these results is shown, namely to prove that the effective cosmological constant after compactification vanishes as a consequence of the classical equations of motion of the string theory. 34 refs. (LEW)
String Amplitudes from Moyal String Field Theory
I. Bars; I. Kishimoto; Y. Matsuo
2002-12-29T23:59:59.000Z
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)
2014-12-01T23:59:59.000Z
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.
Roberto Iengo; Jorge G. Russo
2006-02-20T23:59:59.000Z
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
1995-03-20T23:59:59.000Z
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.
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)
2011-03-11T23:59:59.000Z
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
1996-12-02T23:59:59.000Z
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.
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
South Carolina Community Lights Up the Season with Energy-Efficient Holiday
Broader source: Energy.gov (indexed) [DOE]
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports to3,1,50022,3,,0,,6,1,Separation 23 362Transmission:portion5When purchasingAccelerateCommercialThe Fuel CellSource: Greentech
What Do You Think of Your LED Holiday Lights? | Department of Energy
Broader source: Energy.gov (indexed) [DOE]
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports to3,1,50022,3,,0,,6,1,Separation 23Tribal Energy Program GrantStateAcceptance and Land Use |inrepresentsProcess5We're
Top 5 Things You Didn't Know About Holiday Lights | Department of Energy
Broader source: Energy.gov (indexed) [DOE]
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports to3,1,50022,3,,0,,6,1,Separation 23 362 ofSubscribe to AcquisitionJen CarterSarahDepartmentMarch 8, 2006:of Energy Save
Reheating and Cosmic String Production
Chao-Jun Feng; Xian Gao; Miao Li; Wei Song; Yushu Song
2008-01-04T23:59:59.000Z
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
1991-09-25T23:59:59.000Z
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.
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
2014-10-13T23:59:59.000Z
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.
Stirling number Identities and High energy String Scatterings
Jen-Chi Lee; Yi Yang; Sheng-Lan Ko
2009-09-22T23:59:59.000Z
We use Stirling number identities developed recently in number theory to show that ratios among high energy string scattering amplitudes in the fixed angle regime can be extracted from the Kummer function of the second kind. This result not only brings an interesting bridge between string theory and combinatoric number theory but also sheds light on the understanding of algebraic structure of high energy stringy symmetry.
Fusion of strings and cosmic rays at ultrahigh energies
N. Armesto; M. A. Braun; E. G. Ferreiro; C. Pajares; Yu. M. Shabelski
1996-02-13T23:59:59.000Z
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.
Shooting String Holography of Jet Quenching at RHIC and LHC
Andrej Ficnar; Steven S. Gubser; Miklos Gyulassy
2014-11-07T23:59:59.000Z
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.
String Theory: Progress and Problems
John H. Schwarz
2007-03-05T23:59:59.000Z
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.
Miftachul Hadi; Malcolm Anderson; Andri Husein
2014-05-07T23:59:59.000Z
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
2010-01-08T23:59:59.000Z
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.
Current balancing for battery strings
Galloway, James H. (New Baltimore, MI)
1985-01-01T23:59:59.000Z
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.
John H. Schwarz
2003-04-28T23:59:59.000Z
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.
Casalbuoni, Roberto; Gomis, Joaquim; Longhi, Giorgio [Department of Physics, University of Florence, INFN, Florence (Italy) and Galileo Galilei Institute for Theoretical Physics, Florence (Italy); PH-TH Division, CERN, CH -1211 Geneva 23 (Switzerland) and Departament d'Estructura i Constituents de la Materia, Facultat de Fisica, Universitat de Barcelona, Diagonal 647, 08028 Barcelona (Spain); Department of Physics, University of Florence and INFN, Florence (Italy)
2007-12-15T23:59:59.000Z
We construct a classical nonrelativistic string model in 3+1 dimensions. The model contains a spurion tensor field that is responsible for the noncommutative structure of the model. Under double-dimensional reduction the model reduces to the exotic nonrelativistic particle in 2+1 dimensions.
Device for balancing parallel strings
Mashikian, Matthew S. (Storrs, CT)
1985-01-01T23:59:59.000Z
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.
Your Holidays ... Brought to You by Fuel Cells | Department of Energy
Office of Environmental Management (EM)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports to3,1,50022,3,,0,,6,1,Separation 23 362 334 318Cubic Feet)89312ForumsServices|MaterialManagement United StatesHolidays ... Brought to
A merged two-stage converter for LED lighting applications
Ranson, John (John David)
2012-01-01T23:59:59.000Z
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. ...
Reasonover, Frances L.; Sweeten, Mary K.
1981-01-01T23:59:59.000Z
ingredients in skillet and simmer 15 minutes. Serve warm with wooden picks. Half a lime on a small dish is a colorful holder for the picks. FRENCH FRIED SAUERKRAUT BALLS 1/ 4 pound cooked ham 1/4 pound cooked corned beef 1/ 4 pound bulk sausage (raw) 1.... 2 cans pineapple juice 1 stick whole cinnamon 1 tablespoon whole cloves Sugar or honey to taste (try 1/ 2 cup) Combine ingredients and bring to a simmer. Strain and serve hot. 9 MULLED APPLE CIDER 2 sticks cinnamon 2 jugs apple cider (1...
Reasonover, Frances L.; Sweeten, Mary K.
1981-01-01T23:59:59.000Z
as they have been prepared and leave refriger ated foods until time to be served. Remove frozen foods such as parfait or ice cream from the freezer just before serving to make them easy to eat. If food is to be left at room temperature for more than an hour... out clean. Cool on wire rack one-half hour and then loosen edges and unmold. Wrap cake tightly in foil or in a cloth saturated with brandy. Refrigerate or freezer wrap and freeze. (Two days before using, thaw wrapped cake at room temperature...
Svrcek, Peter; /Stanford U., Phys. Dept. /SLAC; Witten, Edward; /Princeton, Inst. Advanced Study
2006-06-09T23:59:59.000Z
In the context of string theory, axions appear to provide the most plausible solution of the strong CP problem. However, as has been known for a long time, in many string-based models, the axion coupling parameter Fa is several orders of magnitude higher than the standard cosmological bounds. We re-examine this problem in a variety of models, showing that Fa is close to the GUT scale or above in many models that have GUT-like phenomenology, as well as some that do not. On the other hand, in some models with Standard Model gauge fields supported on vanishing cycles, it is possible for Fa to be well below the GUT scale.
A. Gorsky; M. Shifman; A. Yung
2006-01-18T23:59:59.000Z
We address two distinct but related issues: (i) the impact of (two-dimensional) axions in a two-dimensional theory known to model confinement, the CP(N-1) model; (ii) bulk axions in four-dimensional Yang-Mills theory supporting non-Abelian strings. In the first case n, \\bar n kinks play the role of "quarks." They are known to be confined. We show that introduction of axions leads to deconfinement (at very large distances). This is akin to the phenomenon of wall liberation in four-dimensional Yang-Mills theory. In the second case we demonstrate that the bulk axion does not liberate confined (anti)monopoles, in contradistinction with the two-dimensional model. A novel physical effect which we observe is the axion radiation caused by monopole-antimonopole pairs attached to the non-Abelian strings.
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.
2015-02-01T23:59:59.000Z
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)
2013-10-01T23:59:59.000Z
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
2007-01-06T23:59:59.000Z
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.
2011-01-01T23:59:59.000Z
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.
RHIC | String Theory Predicts an Experimental Result
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
that originally appeared in the online publication symmetry breaking. A first: String theory predicts an experimental result One of the biggest criticisms of string theory is that...
Ramakrishnan Iyer; Clifford V. Johnson; Jeffrey S. Pennington
2010-02-05T23:59:59.000Z
We uncover a remarkable role that an infinite hierarchy of non-linear differential equations plays in organizing and connecting certain {hat c}<1 string theories non-perturbatively. We are able to embed the type 0A and 0B (A,A) minimal string theories into this single framework. The string theories arise as special limits of a rich system of equations underpinned by an integrable system known as the dispersive 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.
David J. Gross; Washington Taylor
2001-06-04T23:59:59.000Z
We describe projection operators in the matter sector of Witten's cubic string field theory using modes on the right and left halves of the string. These projection operators represent a step towards an analytic solution of the equations of motion of the full string field theory, and can be used to construct Dp-brane solutions of the string field theory when the BRST operator Q is taken to be pure ghost, as suggested in the recent conjecture by Rastelli, Sen and Zwiebach. We show that a family of solutions related to the sliver state are rank one projection operators on the appropriate space of half-string functionals, and we construct higher rank projection operators corresponding to configurations of multiple D-branes.
David J. Gross; Washington Taylor
2001-06-27T23:59:59.000Z
We describe the ghost sector of cubic string field theory in terms of degrees of freedom on the two halves of a split string. In particular, we represent a class of pure ghost BRST operators as operators on the space of half-string functionals. These BRST operators were postulated by Rastelli, Sen, and Zwiebach to give a description of cubic string field theory in the closed string vacuum arising from condensation of a D25-brane in the original tachyonic theory. We find a class of solutions for the ghost equations of motion using the pure ghost BRST operators. We find a vanishing action for these solutions, and discuss possible interpretations of this result. The form of the solutions we find in the pure ghost theory suggests an analogous class of solutions in the original theory on the D25-brane with BRST operator Q_B coupling the matter and ghost sectors.
String-theoretic breakdown of effective field theory near black hole horizons
Dodelson, Matthew
2015-01-01T23:59:59.000Z
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...
Emergence String and Mass Formulas of Hadrons
Yi-Fang Chang
2011-07-19T23:59:59.000Z
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.
Strings, higher curvature corrections, and black holes
Thomas Mohaupt
2005-12-05T23:59:59.000Z
We review old and recent results on subleading contributions to black hole entropy in string theory.
C. S. Lam
1994-06-24T23:59:59.000Z
A low energy string theory should reduce to an ordinary quantum field theory, but in reality the structures of the two are so different as to make the equivalence obscure. The string formalism is more symmetrical between the spacetime and the internal degrees of freedom, thus resulting in considerable simplification in practical calculations and novel insights in theoretical understandings. We review here how tree or multiloop field-theoretical diagrams can be organized in a string-like manner to take advantage of this computational and conceptual simplicity.
Radio bursts from superconducting strings
Yi-Fu Cai; Eray Sabancilar; Tanmay Vachaspati
2012-01-30T23:59:59.000Z
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
2012-05-14T23:59:59.000Z
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.
M-strings, Elliptic Genera and N=4 String Amplitudes
Stefan Hohenegger; Amer Iqbal
2014-03-11T23:59:59.000Z
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.
String Theory: The Early Years
John H. Schwarz
2000-07-26T23:59:59.000Z
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
2000-11-09T23:59:59.000Z
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.
Phenomenology of heterotic and type II orientifold string models
Mayes, Van Eric
2009-05-15T23:59:59.000Z
. SupersymmetryConditionsintheOpenString Sector . . . . . . . . . . . . . . . . . . . . . . . . 73 5. RR Tadpole Cancellation and K-theory Constraints . 73 6. The Green-Schwarz Mechanism for Flipped SU(5) GUT Construction . . . . . . . . . . . . . . . . . . . . 75...)?SU(2)L?SU(2)R?[U(2)4? U(1)3]. The ?0d representations indicate light, non-chiral matter which is present between pairs of fractional branes which wrap homologically identical bulk cycles, but difier in their twisted cycles. 98 XVI Stacks, wrapping...
Axions as quintessence in string theory
Panda, Sudhakar [Harish-Chandra Research Institute, Allahabad 211019 (India); Sumitomo, Yoske; Trivedi, Sandip P. [Tata Institute of Fundamental Research, Mumbai 400005 (India)
2011-04-15T23:59:59.000Z
We construct a model of quintessence in string theory based on the idea of axion monodromy as discussed by McAllister, Silverstein and Westphal [L. McAllister, E. Silverstein, and A. Westphal, Phys. Rev. D 82, 046003 (2010)]. In the model, the quintessence field is an axion whose shift symmetry is broken by the presence of 5-branes which are placed in highly warped throats. This gives rise to a potential for the axion field which is slowly varying, even after incorporating the effects of moduli stabilization and supersymmetry breaking. We find that the resulting time dependence in the equation of state of dark energy is potentially detectable, depending on the initial conditions. The model has many very light extra particles which live in the highly warped throats, but these are hard to detect. A signal in the rotation of the CMB polarization can also possibly arise.
Finite Temperature Gases of Fermionic Strings
Shyamoli Chaudhuri
2005-09-12T23:59:59.000Z
We show that in the absence of a Ramond-Ramond sector both the type IIA and type IIB free string gases have a thermal instability due to low temperature tachyon modes. The gas of free IIA strings undergoes a thermal duality transition into a gas of free IIB strings at the self-dual temperature. The free heterotic string gas is a tachyon-free ensemble with gauge symmetry SO(16)$\\times$SO(16) in the presence of a timelike Wilson line background. It exhibits a holographic duality relation undergoing a self-dual phase transition with positive free energy and positive specific heat. The type IB open and closed string ensemble is related by thermal duality to the type I' string ensemble. We identify the order parameter for the Kosterlitz-Thouless phase transition from a low temperature gas of short open strings to a high temperature long string phase at or below T_C. Note Added (Sep 2005).
Acoustic data transmission through a drill string
Drumheller, D.S.
1988-04-21T23:59:59.000Z
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.
Running anti-de Sitter radius from QCD-like strings
Yu-tin Huang; Warren Siegel
2007-07-10T23:59:59.000Z
We consider renormalization effects for a bosonic QCD-like string, whose partons have $1/p^{2}$ propagators instead of Gaussian. Classically this model resembles (the bosonic part of) the projective light-cone (zero-radius) limit of a string on an AdS${}_5$ background, where Schwinger parameters give rise to the fifth dimension. Quantum effects generate dynamics for this dimension, producing an AdS${}_5$ background with a running radius. The projective light-cone is the high-energy limit: Holography is enforced dynamically.
Quadratic superconducting cosmic strings revisited
Mustapha Azreg-Aïnou
2008-02-22T23:59:59.000Z
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
String Theory at Snowmass Michael Dine
California at Santa Cruz, University of
String Theory at Snowmass Michael Dine Santa Cruz Institute for Particle Physics, University of California, Santa Cruz, CA 95064 (Dated: September 23, 2002) This is the summary talk for the String Theory interested in string theory, quantum gravity, and related issues met to discuss the questions: which future
Non-Abelian Strings and Axions
Shifman, M. [William I. Fine Theoretical Physics Institute, University of Minnesota, Minneapolis, MN 55455 (United States)
2010-08-30T23:59:59.000Z
Axion-like fields can have a strong impact on non-Abelian strings. I discuss axion connection to such strings and its implications in two cases: (i) axion localized on the strings, and (ii) axions propagating in the four-dimensional bulk.
Introduction to the theory of strings
Peskin, M.E.
1985-10-01T23:59:59.000Z
These lectures present, from an introductory perspective, some basic aspects of the quantum theory of strings. They treat (1) the kinematics, spectrum, and scattering amplitude of the bosonic string, (2) the spectrum and supersymmetry of Green-Schwarz superstring, and (3) the identification of the underlying gauge invariances of the string theory. 43 refs.
Sales Tax Exemption for Energy-Efficient Products (Sales Tax Holiday)
Broader source: Energy.gov [DOE]
This incentive is available for dishwashers, clothes washers, air conditioners, ceiling fans, compact fluorescent light bulbs, dehumidifiers, programmable thermostats, refrigerators, doors and wi...
Sales Tax Exemption for Energy-Efficient Products (Sales Tax Holiday)
Broader source: Energy.gov [DOE]
Virginia allows a four-day sales tax* exemption for dishwashers, clothes washers, air conditioners, ceiling fans, light bulb, dehumidifiers, programmable thermostat and refrigerators that meet fe...
String Universality in Six Dimensions
Vijay Kumar; Washington Taylor
2009-10-10T23:59:59.000Z
In six dimensions, cancellation of gauge, gravitational, and mixed anomalies strongly constrains the set of quantum field theories which can be coupled consistently to gravity. We show that for some classes of six-dimensional supersymmetric gauge theories coupled to gravity, the anomaly cancellation conditions are equivalent to tadpole cancellation and other constraints on the matter content of heterotic/type I compactifications on K3. In these cases, all consistent 6D supergravity theories have a realization in string theory. We find one example which may arise from a novel string compactification, and we identify a new infinite family of models satisfying anomaly factorization. We find, however, that this infinite family of models, as well as other infinite families of models previously identified by Schwarz are pathological. We suggest that it may be feasible to demonstrate that there is a string theoretic realization of all consistent six-dimensional supergravity theories which have Lagrangian descriptions with arbitrary gauge and matter content. We attempt to frame this hypothesis of string universality as a concrete conjecture.
Gordon Chalmers; Olaf Lechtenfeld; Bernd Niemeyer
2000-09-08T23:59:59.000Z
We calculate the genus-one three- and four-point amplitudes in the 2+2 dimensional closed N=(2,2) worldsheet supersymmetric string within the RNS formulation. Vertex operators are redefined with the incorporation of spinor helicity techniques, and the quantum scattering is shown to be manifestly gauge and Lorentz invariant after normalizing the string states. The continuous spin structure summation over the monodromies of the worldsheet fermions is carried out explicitly, and the field-theory limit is extracted. The amplitude in this limit is shown to be the maximally helicity violating amplitude in pure gravity evaluated in a two-dimensional setting, which vanishes, unlike the four-dimensional result. The vanishing of the genus-one N=2 closed string amplitude is related to the absence of one-loop divergences in dimensionally regulated IIB supergravity. Comparisons and contrasts between self-dual field theory and the N=2 string theory are made at the quantum level; they have different S-matrices. Finally, we point to further relations with self-dual field theory and two-dimensional models.
Naohiro Kanda
2011-06-03T23:59:59.000Z
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)}$.
Hall, David R. (Provo, UT); Pixton, David S. (Lehi, UT); Briscoe, Michael (Lehi, UT); McPherson, James (Sandy, UT)
2007-12-04T23:59:59.000Z
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.
Eisenstein Series in String Theory
N. A. Obers; B. Pioline
2000-03-01T23:59:59.000Z
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).
Cosmological consequences of string axions
Kain, Ben [Department of Physics, University of California and Theoretical Physics Group, Bldg. 50A5104, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)
2006-06-15T23:59:59.000Z
Axion fluctuations generated during inflation lead to isocurvature and non-Gaussian temperature fluctuations in the cosmic microwave background radiation. Following a previous analysis for the model independent string axion we consider the consequences of a measurement of these fluctuations for two additional string axions. We do so independent of any cosmological assumptions. The first axion has been shown to solve the strong CP problem for most compactifications of the heterotic string while the second axion, which does not solve the strong CP problem, obeys a mass formula which is independent of the axion scale. We find that if gravitational waves interpreted as arising from inflation are observed by the PLANCK polarimetry experiment with a Hubble constant during inflation of H{sub inf} > or approx. 10{sup 13} GeV the existence of the first axion is ruled out and the second axion cannot obey the scale independent mass formula. In an appendix we quantitatively justify the often held assumption that temperature corrections to the zero temperature QCD axion mass may be ignored for temperatures T < or approx. {lambda}{sub QCD}.
Cosmological Consequences of String Axions
Kain, Ben
2005-12-15T23:59:59.000Z
Axion fluctuations generated during inflation lead to isocurvature and non-Gaussian temperature fluctuations in the cosmic microwave background radiation. Following a previous analysis for the model independent string axion we consider the consequences of a measurement of these fluctuations for two additional string axions. We do so independent of any cosmological assumptions except for the axions being massless during inflation. The first axion has been shown to solve the strong CP problem for most compactifications of the heterotic string while the second axion, which does not solve the strong CP problem, obeys a mass formula which is independent of the axion scale. We find that if gravitational waves interpreted as arising from inflation are observed by the PLANCK polarimetry experiment with a Hubble constant during inflation of H{sub inf} {approx}> 10{sup 13} GeV the existence of the first axion is ruled out and the second axion cannot obey the scale independent mass formula. In an appendix we quantitatively justify the often held assumption that temperature corrections to the zero temperature QCD axion mass may be ignored for temperatures T {approx}< {Lambda}{sub QCD}.
Loop Gas Model for Open Strings
V. Kazakov; I. Kostov
1992-05-18T23:59:59.000Z
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.
Open string moduli in Kachru-Kallosh-Linde-Trivedi compactifications
Aharony, Ofer; Antebi, Yaron E.; Berkooz, Micha [Department of Particle Physics, Weizmann Institute of Science, Rehovot 76100 (Israel)
2005-11-15T23:59:59.000Z
In the Kachru-Kallosh-Linde-Trivedi (KKLT) de-Sitter construction one introduces an anti-D3-brane that breaks the supersymmetry and leads to a positive cosmological constant. In this paper we investigate the open string moduli associated with this anti-D3-brane, corresponding to its position on the S{sup 3} at the tip of the deformed conifold. We show that in the KKLT construction these moduli are very light, and we suggest a possible way to give these moduli a large mass by putting orientifold planes in the KKLT ''throat.''.
Energy radiated from a fluctuating selfdual string
Andreas Gustavsson
2005-06-06T23:59:59.000Z
We compute the energy that is radiated from a fluctuating selfdual string in the large $N$ limit of $A_{N-1}$ theory using the AdS-CFT correspondence. We find that the radiated energy is given by a non-local expression integrated over the string world-sheet. We also make the corresponding computation for a charged string in six-dimensional classical electrodynamics, thereby generalizing the Larmor formula for the radiated energy from an accelerated point particle.
Gamma Ray Bursts from Ordinary Cosmic Strings
R. H. Brandenberger; A. T. Sornborger; M. Trodden
1993-02-12T23:59:59.000Z
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.
String theory: big problem for small size
S. Sahoo
2012-09-25T23:59:59.000Z
String theory is the most promising candidate theory for a unified description of all fundamental forces exist in the nature. It provides a mathematical framework that combine quantum theory with Einstein's general theory of relativity. But due to the extremely small size of strings, nobody has been able to detect it directly in the laboratory till today. In this article, we have presented a general introduction to string theory.
$O(d,d)$-Covariant String Cosmology
M. Gasperini; G. Veneziano
1991-12-17T23:59:59.000Z
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
1992-01-24T23:59:59.000Z
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.
Have You Used LED Light Strings? | Department of Energy
Broader source: Energy.gov (indexed) [DOE]
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports to3,1,50022,3,,0,,6,1,Separation 23 362 ofSubscribe toDepartmentDraftRSS August 25, 2015CommitteeEric Barendsen Energy Technology
The Three-String Vertex for a Plane-Wave Background
John H. Schwarz
2003-12-23T23:59:59.000Z
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.
Big-Bang Nucleosynthesis and Gamma-Ray Constraints on Cosmic Strings with a large Higgs condensate
H. F. Santana Mota; Mark Hindmarsh
2015-01-06T23:59:59.000Z
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.
Melt dumping in string stabilized ribbon growth
Sachs, Emanuel M. (42 Old Middlesex Rd., Belmont, MA 02178)
1986-12-09T23:59:59.000Z
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.
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)
2006-06-19T23:59:59.000Z
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.
Microscopic unitary description of tidal excitations in high-energy string-brane collisions
Giuseppe D'Appollonio; Paolo Di Vecchia; Rodolfo Russo; Gabriele Veneziano
2013-11-15T23:59:59.000Z
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.
Vibration monitoring system for drill string
Wassell, M.E.
1993-07-13T23:59:59.000Z
A vibration monitoring system is described for use in monitoring lateral and torsional vibrations in a drill string comprising: a drill string component having an outer surface; first accelerometer means A[sub 1] for measuring tangential acceleration; second accelerometer means A[sub 2] for measuring tangential acceleration; third accelerometer means A[sub 3] for measuring tangential acceleration; said first, second and third accelerometer means A[sub 1], A[sub 2] and A[sub 3] being mounted in said drill string component and being spaced from one another to measure acceleration forces on said drill string component tangentially with respect to the outer surface of said component wherein said first, second and third accelerometer means are adapted to measure and distinguish between lateral and torsional vibrations exerted on said drill string component.
Wiggly cosmic strings accrete dark energy
Pedro F. Gonzalez-Diaz; Jose A. Jimenez Madrid
2005-06-29T23:59:59.000Z
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.
Electric Magnetic Duality in String Theory
Ashoke Sen
1992-10-06T23:59:59.000Z
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.
String-theoretic breakdown of effective field theory near black hole horizons
Matthew Dodelson; Eva Silverstein
2015-04-21T23:59:59.000Z
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 albeit not in a direct analogue of the black hole process. We discuss applications of this effect to the firewall paradox, and estimate the time and distance scales it predicts for new physics near black hole and cosmological horizons.
Proton stability in grand unified theories, in strings, and in branes
Pran Nath; Pavel Fileviez Perez
2007-04-23T23:59:59.000Z
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.
Effects of Overlapping Strings in pp Collisions
Christian Bierlich; Gösta Gustafson; Leif Lönnblad; Andrey Tarasov
2015-02-13T23:59:59.000Z
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 PYTHIA 8 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 [Lund University; Gustafson, Gösta [Lund University; Lönnblad, Leif [Lund University; Tarasov, Andrey [JLAB
2015-03-01T23:59:59.000Z
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
2015-03-01T23:59:59.000Z
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.
1986-01-01T23:59:59.000Z
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)
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
Cosmological String Backgrounds from Gauged WZW Models
C. Kounnas; D. Luest
1992-05-18T23:59:59.000Z
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.
SU(4) pure-gauge string tensions
Shigemi Ohta; Matthew Wingate
1998-08-19T23:59:59.000Z
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.
A. Klemm; R. Schimmrigk
1992-04-20T23:59:59.000Z
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.
Smart lighting: New Roles for Light
Salama, Khaled
Smart lighting: New Roles for Light in the Solid State Lighting World Robert F. Karlicek, Jr. Director, Smart Lighting Engineering Research Center Professor, Electrical, Systems and Computer Lighting · What is Smart Lighting · Technology Barriers to Smart Lighting · Visible Light Communications
Broader source: Energy.gov [DOE]
Commercial lighting accounts for more than 20 percent of total commercial building energy use. The Energy Department works to reduce lighting energy use through research and deployment.
Semiclassical analysis of string-gauge duality on noncommutative space
Rashkov, R.C.; Viswanathan, K.S.; Yang Yi [Department of Physics, Sofia University, 1164 Sofia (Bulgaria); Department of Physics, Simon Fraser University, Burnaby, British Columbia (Canada); Department of Electrophysics, National Chiao Tung University, Hsinchu, Taiwan (China)
2004-10-15T23:59:59.000Z
We use semiclassical methods to study closed strings in the modified AdS{sub 5}xS{sup 5} background with constant B fields. The pointlike closed strings and the stretched closed strings rotating around the big circle of S{sup 5} are considered. Quantization of these closed string leads to a time-dependent string spectrum, which we argue corresponds to the renormalization-group flow of the dual noncommutative Yang-Mills theory.
Mining Energy from a Black Hole by Strings
V. Frolov; D. Fursaev
2001-05-10T23:59:59.000Z
We discuss how cosmic strings can be used to mine energy from black holes. A string attached to the black hole gives rise to an additional channel for the energy release. It is demonstrated that when a string crosses the event horizon, its transverse degrees of freedom are thermally excited and thermal string perturbations propagate along the string to infinity. The internal metric induced on the 2D worldsheet of the static string crossing the horizon describes a 2D black hole. For this reason thermal radiation of string excitations propagating along the string can be interpreted as Hawking radiation of the 2D black hole. It is shown that the rate of energy emission through the string channel is of the same order of magnitude as the bulk radiation of the black hole. Thus, for N strings attached to the black hole the efficiency of string channels is increased by factor N. We discuss restrictions on N which exist because of the finite thickness of strings, the gravitational backreaction and quantum fluctuations. Our conclusion is that the energy emission rate by strings can be increased as compared to the standard emission in the bulk by the factor 10^3 for GUT strings and up to the factor 10^{31} for electroweak strings.
String field theory and tachyon dynamics
Yang, Haitang, Ph. D. Massachusetts Institute of Technology
2006-01-01T23:59:59.000Z
In this thesis we present some works done during my doctoral studies. These results focus on two directions. The first one is motivated by tachyon dynamics in open string theory. We calculate the stress tensors for the ...
Effect of cosmic string on spin dynamics
Debashree Chowdhury; B. Basu
2014-11-07T23:59:59.000Z
In the present paper, we have investigated the role of cosmic string on spin current and Hall electric field. Due to the background cosmic string, the modified electric field of the system generates renormalized spin orbit coupling, which induces a modified non-Abelian gauge field. The defect causes a change in the AB and AC phases appearing due to the modified electromagnetic field. In addition, for a time varying electric field we perform explicit analytic calculations to derive the exact form of spin electric field and spin current, which is defect parameter dependent and of oscillating type. Furthermore, in an asymmetric crystal within the Drude model approach we investigate the dependence of the cosmic string parameters on cosmic string induced Hall electric field.
Two-dimensional QCD and strings
D. J. Gross; W. Taylor
1993-11-12T23:59:59.000Z
A review is given of recent research on two-dimensional gauge theories, with particular emphasis on the equivalence between these theories and certain string theories with a two-dimensional target space. Some related open problems are discussed.
Axions from cosmic string and wall decay
Hagmann, C A
2010-03-10T23:59:59.000Z
If inflation occurred with a reheat temperature > T{sub PQ}, axions from the decay of global axion strings and domain walls would make an important contribution to the cosmological energy density, comparable to that from vacuum misalignment. Several groups have numerically studied the evolution of axion strings and walls in the past, however substantial uncertainties remain in their contribution to the present density {Omega}{sub a,string+wall} {approx} 1-100 (f{sub a}/10{sup 12} GeV){sup 7/6}, where f{sub a} is the axion decay constant. I will describe the numerical methods used in our simulations and show results for several string and wall configurations.
Axions from cosmic string and wall decay
Hagmann, Chris [Lawrence Livermore National Laboratory, L-59, 7000 East Ave, Livermore, CA (United States)
2010-08-30T23:59:59.000Z
If inflation occurred with a reheat temperature > T{sub PQ}, axions from the decay of global axion strings and domain walls would make an important contribution to the cosmological energy density, comparable to that from vacuum misalignment. Several groups have numerically studied the evolution of axion strings and walls in the past, however substantial uncertainties remain in their contribution to the present density {Omega}{sub a,string+wall{approx}}1-100(f{sub a}/10{sup 12} GeV){sup 7/6}, where f{sub a} is the axion decay constant. I will describe the numerical methods used in our simulations and show results for several string and wall configurations.
Introduction to string and superstring theory II
Peskin, M.E.
1987-03-01T23:59:59.000Z
Conformal field theory is reviewed, then conformal invariance is used to rederive the basic results on the embedding dimensionality for bosonic and fermionic strings. The spectrum of the bosonic and the computation of scattering amplitudes are discussed. The formalism used is extended to clarify the origin of Yang-Mills gauge invariance in the open bosonic string theory. The question of the general-coordinate gauge invariance of string theory is addressed, presenting two disparate viewpoints on this question. A brief introduction is then given of the reduction from the idealized string theory in 10 extended dimensions to more realistic solutions in which all but 4 of these dimensions are compactified. The state of knowledge about the space-time supersymmetry of the superstring from the covariant viewpoint is outlined. An approach for identifying possible 6-dimensional spaces which might represent the form of the compact dimensions is discussed, and the orbifold scheme of compactification is presented. 77 refs., 18 figs. (LEW)
Compressed Indexes for Approximate String Matching
Sung, Wing-Kin Ken"
Compressed Indexes for Approximate String Matching Ho-Leung Chan1 Tak-Wah Lam1, Wing-Kin Sung2 Siu the index space to O(n log n). Huynh et al. [10] and Lam et al. [11] further compressed the index to O,wongss}@comp.nus.edu.sg Abstract. We revisit the problem of indexing a string S[1..n] to support searching all substrings
Cosmological Constant and Axions in String Theory
Svrcek, Peter; /Stanford U., Phys. Dept. /SLAC
2006-08-18T23:59:59.000Z
String theory axions appear to be promising candidates for explaining cosmological constant via quintessence. In this paper, we study conditions on the string compactifications under which axion quintessence can happen. For sufficiently large number of axions, cosmological constant can be accounted for as the potential energy of axions that have not yet relaxed to their minima. In compactifications that incorporate unified models of particle physics, the height of the axion potential can naturally fall close to the observed value of cosmological constant.
A keV String Axion from High Scale Supersymmetry
Brian Henning; John Kehayias; Hitoshi Murayama; David Pinner; Tsutomu T. Yanagida
2015-03-20T23:59:59.000Z
Various theoretical and experimental considerations motivate models with high scale supersymmetry breaking. While such models may be difficult to test in colliders, we propose looking for signatures at much lower energies. We show that a keV line in the X-ray spectrum of galaxy clusters (such as the recently disputed 3.5 keV observation) can have its origin in a universal string axion coupled to a hidden supersymmetry breaking sector. A linear combination of the string axion and an additional axion in the hidden sector remains light, obtaining a mass of order 10 keV through supersymmetry breaking dynamics. In order to explain the X-ray line, the scale of supersymmetry breaking must be about $10^{11-12}$ GeV. This motivates high scale supersymmetry as in pure gravity mediation or minimal split supersymmetry and is consistent with all current limits. Since the axion mass is controlled by a dynamical mass scale, this mass can be much higher during inflation, avoiding isocurvature (and domain wall) problems associated with high scale inflation. In an appendix we present a mechanism for dilaton stabilization that additionally leads to $\\mathcal{O}(1)$ modifications of the gaugino mass from anomaly mediation.
Is the Universal String Axion the QCD Axion
Gaillard, Mary K.; Kain, Ben
2005-10-14T23:59:59.000Z
We consider the class of effective supergravity theories from the weakly coupled heterotic string in which local supersymmetry is broken by gaugino condensation in a hidden sector, with dilaton stabilization achieved through corrections to the classical dilaton Kahler potential. If there is a single hidden condensing (simple) gauge group, the axion is massless (up to contributions from higher dimension operators) above the QCD condensation scale. We show how the standard relation between the axion mass and its Planck scale coupling constant is modified in this class of models due to a contribution to the axion-gluon coupling that appears below the scale of supersymmetry breaking when gluinos are integrated out. In particular there is a point of enhanced symmetry in parameter space where the axion mass is suppressed. We revisit the question of the universal axion as the Peccei-Quinn axion in the light of these results, and find that the strong CP problem is avoided in most compactifications of the weakly coupled heterotic string.
Artificial light and quantum order in systems of screened dipoles
Xiao-Gang Wen
2003-04-14T23:59:59.000Z
The origin of light is a unsolved mystery in nature. Recently, it was suggested that light may originate from a new kind of order - quantum order. To test this idea in experiments, we study systems of screened magnetic/electric dipoles in 2D and 3D lattices. We show that our models contain an artificial light -- a photon-like collective excitation. We discuss how to design realistic devices that realize our models. We show that the ``speed of light'' and the ``fine structure constant'' of the artificial light can be tuned in our models. The properties of artificial atoms (bound states of pairs of artificial charges) are also discussed. The existence of artificial light (as well as artificial electron) in condensed matter systems suggests that elementary particles, such as light and electron, may not be elementary. They may be collective excitations of quantum order in our vacuum. Our models further suggest that a gauge theory is a string-net theory in disguise. Light is a fluctuation of nets of large closed strings and charge is the end of open strings.
Accidental inflation in string theory
Linde, Andrei; Westphal, Alexander, E-mail: alinde@stanford.edu, E-mail: awestpha@stanford.edu [Department of Physics, Stanford University, Stanford, CA 94305-4060 (United States)
2008-03-15T23:59:59.000Z
We show that inflation in type IIB string theory driven by the volume modulus can be realized in the context of the racetrack-based Kallosh-Linde model (KL) of moduli stabilization. Inflation here arises through the volume modulus slow-rolling down from a flat hilltop or inflection point of the scalar potential. This situation can be quite generic in the landscape, where by uplifting one of the two adjacent minima one can turn the barrier either into a flat saddle point or into an inflection point supporting eternal inflation. The resulting spectral index is tunable in the range of 0.93{approx}
String Junctions and Holographic Interfaces
Marco Chiodaroli; Michael Gutperle; Ling-Yan Hung; Darya Krym
2010-11-22T23:59:59.000Z
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.
Low energy 2+1 string gravity; black hole solutions
A. A. Garcia Diaz; G. Gutierrez Cano
2014-12-17T23:59:59.000Z
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.
On zero-point energy, stability and Hagedorn behavior of Type IIB strings on pp-waves
F. Bigazzi; A. L. Cotrone
2003-09-09T23:59:59.000Z
Type IIB strings on many pp-wave backgrounds, supported either by 5-form or 3-form fluxes, have negative light-cone zero-point energy. This raises the question of their stability and poses possible problems in the definition of their thermodynamic properties. After having pointed out the correct way of calculating the zero-point energy, an issue not fully discussed in literature, we show that these Type IIB strings are classically stable and have well defined thermal properties, exhibiting a Hagedorn behavior.
Perturbative String Thermodynamics near Black Hole Horizons
Thomas G. Mertens; Henri Verschelde; Valentin I. Zakharov
2015-07-01T23:59:59.000Z
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.
Perturbative String Thermodynamics near Black Hole Horizons
Thomas G. Mertens; Henri Verschelde; Valentin I. Zakharov
2014-10-29T23:59:59.000Z
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.
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
String Theory and Math: Why This Marriage May Last
Aganagic, Mina
2015-01-01T23:59:59.000Z
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.
On the solutions to the string equation
A. Schwarz
1991-09-10T23:59:59.000Z
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.
Low Tension Strings on a Cosmological Singularity
Ben Craps; Chethan Krishnan; Ayush Saurabh
2014-09-21T23:59:59.000Z
It has recently been argued that the singularity of the Milne orbifold can be resolved in higher spin theories. In string theory scattering amplitudes, however, the Milne singularity gives rise to ultraviolet divergences that signal uncontrolled backreaction. Since string theory in the low tension limit is expected to be a higher spin theory (although precise proposals only exist in special cases), we investigate what happens to these scattering amplitudes in the low tension limit. We point out that the known problematic ultraviolet divergences disappear in this limit. In addition we systematically identify all divergences of the simplest 2-to-2 string scattering amplitude on the Milne orbifold, and argue that the divergences that survive in the low tension limit have sensible infrared interpretations.
Closed strings from decaying D-branes
Neil Lambert; Hong Liu; Juan Maldacena
2007-02-05T23:59:59.000Z
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.
Perturbative diagrams in string field theory
Washington Taylor
2002-07-13T23:59:59.000Z
A general algorithm is presented which gives a closed-form expression for an arbitrary perturbative diagram of cubic string field theory at any loop order. For any diagram, the resulting expression is given by an integral of a function of several infinite matrices, each built from a finite number of blocks containing the Neumann coefficients of Witten's 3-string vertex. The closed-form expression for any diagram can be approximated by level truncation on oscillator level, giving a computation involving finite size matrices. Some simple tree and loop diagrams are worked out as examples of this approach.
Perturbative computations in string field theory
Washington Taylor
2004-04-15T23:59:59.000Z
These notes describe how perturbative on-shell and off-shell string amplitudes can be computed using string field theory. Computational methods for approximating arbitrary amplitudes are discussed, and compared with standard world-sheet methods for computing on-shell amplitudes. These lecture notes are not self-contained; they contain the material from W. Taylor's TASI 2003 lectures not covered in the recently published ``TASI 2001'' notes {\\tt hep-th/0311017} by Taylor and Zwiebach, and should be read as a supplement to those notes.
Parallel ion strings in linear multipole traps
Mathieu Marciante; Caroline Champenois; J. Pedregosa-Gutierrez; Annette Calisti; Martina Knoop
2011-03-13T23:59:59.000Z
Additional radio-frequency (rf) potentials applied to linear multipole traps create extra field nodes in the radial plane which allow one to confine single ions, or strings of ions, in totally rf field-free regions. The number of nodes depends on the order of the applied multipole potentials and their relative distance can be easily tuned by the amplitude variation of the applied voltages. Simulations using molecular dynamics show that strings of ions can be laser cooled down to the Doppler limit in all directions of space. Once cooled, organized systems can be moved with very limited heating, even if the cooling process is turned off.
Cosmic strings: A problem or a solution
Bennett, D.P.; Bouchet, F.R.
1987-10-01T23:59:59.000Z
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.
Diffractive Scattering and Gauge/String Duality
Tan, Chung-I [Brown University, Providence, Rhode Island, United States
2009-09-01T23:59:59.000Z
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.
The Early Years of String Theory: A Personal Perspective
John H. Schwarz
2009-04-03T23:59:59.000Z
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.
Closed string field theory in a-gauge
Masako Asano; Mitsuhiro Kato
2012-09-09T23:59:59.000Z
We show that a-gauge, a class of covariant gauges developed for bosonic open string field theory, is consistently applied to the closed string field theory. A covariantly gauge-fixed action of massless fields can be systematically derived from a-gauge-fixed action of string field theory.
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
2013-06-13T23:59:59.000Z
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
2014-05-22T23:59:59.000Z
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...
D-branes and string field theory
Sigalov, Ilya
2006-01-01T23:59:59.000Z
In this thesis we study the D-brane physics in the context of Witten's cubic string field theory. We compute first few terms the low energy effective action for the non-abelian gauge field A, from Witten's action. We show ...
Abelian-Higgs strings in Rastall gravity
Eugenio R. Bezerra de Mello; Julio C. Fabris; Betti Hartmann
2015-04-02T23:59:59.000Z
In this paper we analyze Abelian-Higgs strings in a phenomenological model that takes quantum effects in curved space-time into account. This model, first introduced by Rastall, cannot be derived from an action principle. We formulate phenomenological equations of motion under the guiding principle of minimal possible deformation of the standard equations. We construct string solutions that asymptote to a flat space-time with a deficit angle by solving the set of coupled non-linear ordinary differential equations numerically. Decreasing the Rastall parameter from its Einstein gravity value we find that the deficit angle of the space-time increases and becomes equal to $2\\pi$ at some critical value of this parameter that depends on the remaining couplings in the model. For smaller values the resulting solutions are supermassive string solutions possessing a singularity at a finite distance from the string core. Assuming the Higgs boson mass to be on the order of the gauge boson mass we find that also in Rastall gravity this happens only when the symmetry breaking scale is on the order of the Planck mass. We also observe that for specific values of the parameters in the model the energy per unit length becomes proportional to the winding number, i.e. the degree of the map $S^1 \\rightarrow S^1$. Unlike in the BPS limit in Einstein gravity, this is, however, not connect to an underlying mathematical structure, but rather constitutes a would-be-BPS bound.
P. S. Howe; N. D. Lambert; P. C. West
1997-09-09T23:59:59.000Z
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.
Evidence for Non-perturbative String Symmetries
John H. Schwarz
1994-11-29T23:59:59.000Z
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.
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
String inspired effective Lagrangian and Inflationary Universe
E. Abdalla; A. C. V. V. de Siqueira
1993-01-26T23:59:59.000Z
We consider a string inspired effective Lagrangian for the graviton and dilaton, containing Einstein gravity at the zero slope limit. The numerical solution of the problem shows asymptotically an inflationary universe. The time is measured by the dilaton, as one expects. The result is independent of the introduction of ad-hoc self interactions for the dilaton field.
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journal Article) |govInstrumentsmfrirt DocumentationSitesWeather6Environmental1Grandson ofabout/jobs/HighlyHistoryArgonne'sHoisting &Food
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journal Article) |govInstrumentsmfrirt DocumentationSitesWeather6Environmental1Grandson ofabout/jobs/HighlyHistoryArgonne'sHoisting
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journal Article)41cloth Documentation DataDepartment of EnergyOn-Farm1 of 62.1 Print NationalFive-Month Extension ofTH StreetOFFICE
it looks bent at the place where it crosses the water surface. The reason is that light rays do not follow a straight line when they cross a boundary of two different
Open string amplitudes of closed topological vertex
Takasaki, Kanehisa
2015-01-01T23:59:59.000Z
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.
Signal connection for a downhole tool string
Hall, David R.; Hall, Jr., H. Tracy; Pixton, David S.; Bradford, Kline; Fox, Joe; Briscoe, Michael
2006-08-29T23:59:59.000Z
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.
Vacuum selection on the string landscape
Tetteh-Lartey, Edward [Department of Physics, Texas A and M University, College Station, Texas 77845 (United States)
2007-05-15T23:59:59.000Z
I examine some nonanthropic approaches to the string landscape. These approaches are based on finding the initial conditions of the universe using the wave function of the multiverse to select the most probable vacuum out of this landscape. All approaches tackled so far seem to have their own problems and there is no clear-cut alternative to anthropic reasoning. I suggest that finding the initial conditions may be irrelevant since all possible vacua on the landscape are possible initial state conditions and eternal inflation could generate all the other vacua. We are now left to reason out why we are observing the small value of the cosmological constant. I address this issue in the context of noncritical string theory in which all values of the cosmological constant on the landscape are departures from the critical equilibrium state.
Strings, vortex rings, and modes of instability
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Gubser, Steven S.; Nayar, Revant; Parikh, Sarthak
2015-03-01T23:59:59.000Z
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
Kanehisa Takasaki; Toshio Nakatsu
2015-07-25T23:59:59.000Z
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.
Jet fragmentation and gauge/string duality
Yoshitaka Hatta; Toshihiro Matsuo
2008-05-27T23:59:59.000Z
We consider an analog of e^+e^- annihilation in gauge theories which have a dual string description in asymptotically AdS_5 space and discuss the nature of jet fragmentation. We construct the timelike anomalous dimension which governs the scale dependence of the fragmentation function. In the limit of infinite 't Hooft coupling, the average multiplicity rises linearly with the energy and the inclusive spectrum is peaked at the kinematical boundary.
Traversable wormholes in a string cloud
Martin Richarte; Claudio Simeone
2007-11-14T23:59:59.000Z
We study spherically symmetric thin-shell wormholes in a string cloud background in (3+1)-dimensional spacetime. The amount of exotic matter required for the construction, the traversability and the stability under radial perturbations, are analyzed as functions of the parameters of the model. Besides, in the Appendices a non perturbative approach to the dynamics and a possible extension of the analysis to a related model are briefly discussed.
Two Dimensional QCD is a String Theory
David J. Gross; Washington Taylor
1993-01-18T23:59:59.000Z
The partition function of two dimensional QCD on a Riemann surface of area $A$ is expanded as a power series in $1/N$ and $A$. It is shown that the coefficients of this expansion are precisely determined by a sum over maps from a two dimensional surface onto the two dimensional target space. Thus two dimensional QCD has a simple interpretation as a closed string theory.
Non-perturbative String Theory from Water Waves
Ramakrishnan Iyer; Clifford V. Johnson; Jeffrey S. Pennington
2010-11-29T23:59:59.000Z
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.
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
Long-range correlation studies at the SPS energies in MC model with string fusion
Vladimir Kovalenko; Vladimir Vechernin
2015-02-05T23:59:59.000Z
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
2015-01-01T23:59:59.000Z
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...
A casing string model for the personal computer
Zuniga-Pflucker, Manuel Pablo
1988-01-01T23:59:59.000Z
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...
Open String Theory in 1+1 Dimensions
M. Bershadsky; D. Kutasov
1991-10-14T23:59:59.000Z
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.
N. Seiberg; L. Susskind; N. Toumbas
2000-05-04T23:59:59.000Z
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
2007-02-27T23:59:59.000Z
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
2000-10-31T23:59:59.000Z
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.
Efficient solutions for the Far From Most String Problem
Daniele Ferone,,,
niques for string selection and comparison problems in genomics. IEEE. Engineering in Medicine and Biology Magazine, 24(3):81–87, 2005. [29] C.A.S. Oliveira ...
Padgett, Miles [University of Glasgow, Glasgow, Scotland
2010-01-08T23:59:59.000Z
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?
New Light Sources for Tomorrow's Lighting Designs
Krailo, D. A.
NEW LIGHT SOURCES FOR TOMORROW'S LIGHTING DESIGNS David A. Krailo, GTE Products Corporation Sylvania Lighting Center, Danvers, MA. ABSTRACT The lighting industry is driven to provide light sources and light ing systems that, when properly..., and deciding which produce item to select for tonight's dinner. While energy efficiency is a major consideration in any new lighting system design, the sacrifice of lighting quality may cost more in terms oflost productivity and user dissatisfaction than...
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
CMB ISW-lensing bispectrum from cosmic strings
Daisuke Yamauchi; Yuuiti Sendouda; Keitaro Takahashi
2014-10-21T23:59:59.000Z
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 orderto 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, $G\\mu\\ll 10^{-7}$\\,, 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.
Gordon Chalmers
2006-10-13T23:59:59.000Z
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.
The viscosity bound in string theory
Aninda Sinha; Robert C. Myers
2009-09-11T23:59:59.000Z
The ratio of shear viscosity to entropy density $\\eta/s$ of any material in nature has been conjectured to have a lower bound of $1/4\\pi$, the famous KSS bound. We examine string theory models for evidence in favour of and against this conjecture. We show that in a broad class of models quantum corrections yield values of $\\eta/s$ just above the KSS bound. However, incorporating matter fields in the fundamental representation typically leads to violations of this bound. We also outline a program to extend AdS/CFT methods to RHIC phenomenology.
Lattice String Breaking and Heavy Meson Decays
I T Drummond; R R Horgan
1998-11-11T23:59:59.000Z
We show how string breaking on the lattice, treated as a mixing effect, can be related to decay rates for heavy quark systems. We use this to make a preliminary calculation of the energy split at maximum mixing for static quarks in QCD from the decay rate for $\\Upsilon(4S)\\to B{\\bar B}$. We extend the calculation to achieve rough estimates for the contributions of channels involving $B, B^*, B_s and B_s^*$ mesons to the width of the $\\Upsilon(5S)$.
Higher-Spin Geometry and String Theory
D. Francia; A. Sagnotti
2006-02-14T23:59:59.000Z
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.
Quantum string cosmology in the phase space
Ruben Cordero; Erik Diaz; Hugo Garcia-Compean; Francisco J. Turrubiates
2011-09-22T23:59:59.000Z
Deformation quantization is applied to quantize gravitational systems coupled with matter. This quantization procedure is performed explicitly for quantum cosmology of these systems in a flat minisuper(phase)space. The procedure is employed in a quantum string minisuperspace corresponding to an axion-dilaton system in an isotropic FRW Universe. The Wheeler-DeWitt-Moyal equation is obtained and its corresponding Wigner function is given analytically in terms of Meijer's functions. Finally, this Wigner functions is used to extract physical information of the system.
Dynamics of a self-gravitating thin cosmic string
B. Boisseau; C. Charmousis; B. Linet
1997-02-06T23:59:59.000Z
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.
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
Gravitational Radiation from Travelling Waves on D-Strings
Julie D. Blum
2003-08-21T23:59:59.000Z
Boundary states that preserve supersymmetry are constructed for fractional D-strings with travelling waves on a ${\\bf C}^3/ {{\\bf Z}_2\\times {\\bf Z}_2}$ orbifold. The gravitational radiation emitted between two D-strings with antiparallel travelling waves is calculated.
The M Theory Five-Brane and the Heterotic String
John H. Schwarz
1997-05-13T23:59:59.000Z
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.
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
Resonant acoustic transducer system for a well drilling string
Kent, William H. (Westford, MA); Mitchell, Peter G. (Concord, MA)
1981-01-01T23:59:59.000Z
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.
Resonant acoustic transducer system for a well drilling string
Nardi, Anthony P. (Burlington, MA)
1981-01-01T23:59:59.000Z
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.
Quantum Fusion of Strings (Flux Tubes) and Domain Walls
S. Bolognesi; M. Shifman; M. B. Voloshin
2009-05-20T23:59:59.000Z
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.
Comment about UV regularization of basic commutators in string theories
A. Yu. Kamenshchik; I. M. Khalatnikov; M. Martellini
1998-06-24T23:59:59.000Z
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.
Tachyon condensation in boundary string field theory at one loop
K. Bardakci; A. Konechny
2001-08-21T23:59:59.000Z
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.
String stabilized ribbon growth a method for seeding same
Sachs, Emanuel M. (39 Harding Ave., Belmont, MA 02178)
1987-08-25T23:59:59.000Z
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.
Holger B. Nielsen; Masao Ninomiya
2015-03-10T23:59:59.000Z
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.
Strings, black holes, and quantum information
Kallosh, Renata; Linde, Andrei [Department of Physics, Stanford University, Stanford, California 94305 (United States)
2006-05-15T23:59:59.000Z
We find multiple relations between extremal black holes in string theory and 2- and 3-qubit systems in quantum information theory. We show that the entropy of the axion-dilaton extremal black hole is related to the concurrence of a 2-qubit state, whereas the entropy of the STU black holes, Bogomol'nyi-Prasad-Sommerfield (BPS) as well as non-BPS, is related to the 3-tangle of a 3-qubit state. We relate the 3-qubit states with the string theory states with some number of D-branes. We identify a set of large black holes with the maximally entangled Greenberger, Horne, Zeilinger (GHZ) class of states and small black holes with separable, bipartite, and W states. We sort out the relation between 3-qubit states, twistors, octonions, and black holes. We give a simple expression for the entropy and the area of stretched horizon of small black holes in terms of a norm and 2-tangles of a 3-qubit system. Finally, we show that the most general expression for the black hole and black ring entropy in N=8 supergravity/M theory, which is given by the famous quartic Cartan E{sub 7(7)} invariant, can be reduced to Cayley's hyperdeterminant describing the 3-tangle of a 3-qubit state.
Axion inflation in type II string theory
Grimm, Thomas W. [Physikalisches Institut der Universitaet Bonn, Nussallee 12, 53115 Bonn (Germany) and Department of Physics, University of Wisconsin, Madison, WI 53706 (United States)
2008-06-15T23:59:59.000Z
Inflationary models driven by a large number of axion fields are discussed in the context of type IIB compactifications with N=1 supersymmetry. The inflatons arise as the scalar modes of the R-R two-forms evaluated on vanishing two-cycles in the compact geometry. The vanishing cycles are resolved by small two-volumes or NS-NS B fields which sit together with the inflatons in the same supermultiplets. String world sheets wrapping the vanishing cycles correct the metric of the R-R inflatons. They can help to generate kinetic terms close to the Planck scale and a mass hierarchy between the axions and their nonaxionic partners during inflation. At small string coupling, D-brane corrections are subleading in the metric of the R-R inflatons. However, an axion potential can be generated by D1 instantons or gaugino condensates on D5-branes. Models with a sufficiently large number of axions admit regions of chaotic inflation which can stretch over the whole axion field range for potentials from gaugino condensates. These models could allow for a possibly detectable amount of gravitational waves with tensor to scalar ratio as high as r<0.14.
Lighting Inventory Lighting Theatre and Drama
Indiana University
Lighting Inventory Lighting Theatre and Drama Description Totals R.Halls Wells- Metz Light ERS ETC SourceFour 25 25 50 degree ERS Strand Lighting 64 14 24 12 14 36 degree ERS ETC Source Four 15 15 36 degree ERS Strand Lighting 124 60 58 2 4 26 degree ERS ETC SourceFour 2 2 26 degree ERS Strand
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
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5(Million Cubic Feet) Oregon (Including Vehicle Fuel) (Million CubicRefiners Switch toDepartmentquestionnairesU.S. EnergyLighting Sign In About |
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journal Article)41clothThe Bonneville PowerTariff Pages default Sign In AboutIsrelocatesLaserPhotovoltaicDepartmentLiekoLift Forces inLight9
Broader source: Energy.gov [DOE]
Light-Emitting diodes (LEDs) efficiently produce light in a fundamentally different way than any legacy or traditional source of light.
Dynamics of a global string with large Higgs boson mass
C. Charmousis; B. Boisseau; B. Linet
1998-01-12T23:59:59.000Z
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.
First Structure Formation: II. Cosmic String + Hot Dark Matter Models
Tom Abel; Albert Stebbins; Peter Anninos; Michael L. Norman
1997-06-26T23:59:59.000Z
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.
Accretion onto a black hole in a string cloud background
Apratim Ganguly; Sushant G. Ghosh; Sunil D. Maharaj
2014-09-28T23:59:59.000Z
We examine the accretion process onto the black hole with a string cloud background, where the horizon of the black hole has an enlarged radius $r_H=2 M/(1-\\alpha)$, due to the string cloud parameter $\\alpha\\; (0 \\leq \\alpha cloud parameter $\\alpha$. We also find the gas compression ratios and temperature profiles below the accretion radius and at the event horizon. It is shown that the mass accretion rate, for both the relativistic and the non-relativistic fluid by a black hole in the string cloud model, increases with increase in $\\alpha$.
Modified Dispersion Relations from Closed Strings in Toroidal Cosmology
Mar Bastero-Gil; Paul H. Frampton; Laura Mersini
2002-02-13T23:59:59.000Z
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.
Fitting the Galaxy Rotation Curves: Strings versus NFW profile
Yeuk-Kwan E. Cheung; Feng Xu
2008-10-14T23:59:59.000Z
Remarkable fit of galaxy rotation curves is achieved using a simple model from string theory. The rotation curves of the same group of galaxies are also fit using dark matter model with the generalized Navarro-Frenk-White profile for comparison. String model utilizes three free parameters vs five in the dark matter model. The average chi-squared of the string model fit is 1.649 while that of the dark matter model is 1.513. The generalized NFW profile fits marginally better at a price of two more free parameters.
Self-Dual Supergravity from N = 2 Strings
de Boer, J.; Skenderis, K.
1997-09-24T23:59:59.000Z
A new heterotic N = 2 string with manifest target space supersymmetry is constructed by combining a conventional N = 2 string in the right-moving sector and a Green-Schwarz-Berkovits type string in the left-moving sector. The corresponding sigma model is then obtained by turning on background fields for the massless excitations. We compute the beta functions and we partially check the OPE's of the superconformal algebra perturbatively in {alpha}{prime}, all in superspace. The resulting field equations describe N = 1 self-dual supergravity.
A note on string size evolution in phantom cosmology
Soon-Tae Hong
2015-04-05T23:59:59.000Z
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.
String Theory, Supersymmetry, Unification, and All That
John H. Schwarz; Nathan Seiberg
1998-04-22T23:59:59.000Z
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.
Dark Energy Generated by Warped Cosmic Strings
Reinoud Jan Slagter
2014-07-29T23:59:59.000Z
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.
Renewal Strings for Cleaning Astronomical Databases
Storkey, Amos J; Williams, Christopher K I; Mann, Robert G
2014-01-01T23:59:59.000Z
Large astronomical databases obtained from sky surveys such as the SuperCOSMOS Sky Surveys (SSS) invariably suffer from a small number of spurious records coming from artefactual effects of the telescope, satellites and junk objects in orbit around earth and physical defects on the photographic plate or CCD. Though relatively small in number these spurious records present a significant problem in many situations where they can become a large proportion of the records potentially of interest to a given astronomer. In this paper we focus on the four most common causes of unwanted records in the SSS: satellite or aeroplane tracks, scratches fibres and other linear phenomena introduced to the plate, circular halos around bright stars due to internal reflections within the telescope and diffraction spikes near to bright stars. Accurate and robust techniques are needed for locating and flagging such spurious objects. We have developed renewal strings, a probabilistic technique combining the Hough transform, renewal...
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)
2007-08-28T23:59:59.000Z
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.
Duality Symmetric String and M-Theory
David S. Berman; Daniel C. Thompson
2014-12-09T23:59:59.000Z
We review recent developments in duality symmetric string theory. We begin with the world sheet doubled formalism which describes strings in an extended space time with extra coordinates conjugate to winding modes. This formalism is T-duality symmetric and can accommodate non-geometric T-fold backgrounds which are beyond the scope of Riemannian geometry. Vanishing of the conformal anomaly of this theory can be interpreted as a set of spacetime equations for the background fields. These equations follow from an action principle that has been dubbed Double Field Theory (DFT). We review the aspects of generalised geometry relevant for DFT. We outline recent extensions of DFT and explain how, by relaxing the so-called strong constraint with a Scherk Schwarz ansatz, one can obtain backgrounds that simultaneously depend on both the regular and T-dual coordinates. This provides a purely geometric higher dimensional origin to gauged supergravities that arise from non-geometric compactification. We then turn to M-theory and describe recent progress in formulating an E_{n(n)} U-duality covariant description of the dynamics. We describe how spacetime may be extended to accommodate coordinates conjugate to brane wrapping modes and the construction of generalised metrics in this extend space that unite the bosonic fields of supergravity into a single object. We review the action principles for these theories and their novel gauge symmetries. We also describe how a Scherk Schwarz reduction can be applied in the M-theory context and the resulting relationship to the embedding tensor formulation of maximal gauged supergravities.
Exploring the string axiverse with precision black hole physics
Arvanitaki, Asimina [Berkeley Center for Theoretical Physics, University of California, Berkeley, California, 94720 (United States); Theoretical Physics Group, Lawrence Berkeley National Laboratory, Berkeley, California, 94720 (United States); Dubovsky, Sergei [Department of Physics, Stanford University, Stanford, California, 94305 (United States); Institute for Nuclear Research of the Russian Academy of Sciences, 60th October Anniversary Prospect, 7a, 117312 Moscow (Russian Federation)
2011-02-15T23:59:59.000Z
It has recently been suggested that the presence of a plenitude of light axions, an Axiverse, is evidence for the extra dimensions of string theory. We discuss the observational consequences of these axions on astrophysical black holes through the Penrose superradiance process. When an axion Compton wavelength is comparable to the size of a black hole, the axion binds to the black hole ''nucleus'' forming a gravitational atom in the sky. The occupation number of superradiant atomic levels, fed by the energy and angular momentum of the black hole, grows exponentially. The black hole spins down and an axion Bose-Einstein condensate cloud forms around it. When the attractive axion self-interactions become stronger than the gravitational binding energy, the axion cloud collapses, a phenomenon known in condensed matter physics as 'bosenova'. The existence of axions is first diagnosed by gaps in the mass vs spin plot of astrophysical black holes. For young black holes the allowed values of spin are quantized, giving rise to ''Regge trajectories'' inside the gap region. The axion cloud can also be observed directly either through precision mapping of the near-horizon geometry or through gravitational waves coming from the bosenova explosion, as well as axion transitions and annihilations in the gravitational atom. Our estimates suggest that these signals are detectable in upcoming experiments, such as Advanced LIGO, AGIS, and LISA. Current black hole spin measurements imply an upper bound on the QCD axion decay constant of 2x10{sup 17} GeV, while Advanced LIGO can detect signals from a QCD axion cloud with a decay constant as low as the GUT scale. We finally discuss the possibility of observing the {gamma}-rays associated with the bosenova explosion and, perhaps, the radio waves from axion-to-photon conversion for the QCD axion.
Towards a metamaterial simulation of a spinning cosmic string
Tom G. Mackay; Akhlesh Lakhtakia
2009-11-21T23:59:59.000Z
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.
The Fourier-Mukai Transform in String Theory
Bjorn Andreas
2005-05-30T23:59:59.000Z
The article surveys aspects of the Fourier-Mukai transform, its relative version and some of its applications in string theory. To appear in Encyclopedia of Mathematical Physics, published by Elsevier in early 2006. Comments/corrections welcome.
Efficient Solutions for the Far From Most String Problem
Paola Festa
2011-04-07T23:59:59.000Z
Apr 7, 2011 ... Efficient Solutions for the Far From Most String Problem. Paola Festa(paola.festa ***at*** unina.it) Panos M. Pardalos(pardalos ***at*** ufl.edu).
Lovelock black holes in a string cloud background
Tae-Hun Lee; Dharmanand Baboolal; Sushant G. Ghosh
2015-06-11T23:59:59.000Z
We present an exact static, spherically symmetric black hole solution to the third order Lovelock gravity with a string cloud background in seven dimensions for the special case when the second and third order Lovelock coefficients are related via $\\tilde{\\alpha}^2_2=3\\tilde{\\alpha}_3\\;(\\equiv\\alpha^2)$. Further, we examine thermodynamic properties of this black hole to obtain exact expressions for mass, temperature, entropy and also perform the thermodynamic stability analysis. We see that a string cloud background makes a profound influence on horizon structure, thermodynamic properties and the stability of black holes. Interestingly the entropy of the black hole is unaffected due to a string cloud background. However, the critical solution for thermodynamic stability is being affected by a string cloud background.
TASI Lectures on Supergravity and String Vacua in Various Dimensions
Washington Taylor
2011-04-14T23:59:59.000Z
These lectures aim to provide a global picture of the spaces of consistent quantum supergravity theories and string vacua in higher dimensions. The lectures focus on theories in the even dimensions 10, 8, and 6. Supersymmetry, along with with anomaly cancellation and other quantum constraints, places strong limitations on the set of physical theories which can be consistently coupled to gravity in higher-dimensional space-times. As the dimensionality of space-time decreases, the range of possible supergravity theories and the set of known string vacuum constructions expand. These lectures develop the basic technology for describing a variety of string vacua, including heterotic, intersecting brane, and F-theory compactifications. In particular, a systematic presentation is given of the basic elements of F-theory. In each dimension, we summarize the current state of knowledge regarding the extent to which supergravity theories not realized in string theory can be shown to be inconsistent.
Vortex scattering and intercommuting cosmic strings on a noncommutative spacetime
Joseph, Anosh; Trodden, Mark [Department of Physics, Syracuse University, Syracuse, New York 13244 (United States); Center for Particle Cosmology, Department of Physics and Astronomy, University of Pennsylvania, Pennsylvania 19104 (United States)
2010-02-15T23:59:59.000Z
We study the scattering of noncommutative vortices, based on the noncommutative field theory developed in [A. P. Balachandran, T. R. Govindarajan, G. Mangano, A. Pinzul, B. A. Qureshi, and ?>S. Vaidya, Phys. Rev. D 75, 045009 (2007).], as a way to understand the interaction of cosmic strings. In the center-of-mass frame, the effects of noncommutativity vanish, and therefore the reconnection of cosmic strings occurs in an identical manner to the commutative case. However, when scattering occurs in a frame other than the center-of-mass frame, strings still reconnect but the well-known 90 deg. scattering no longer need correspond to the head-on collision of the strings, due to the breakdown of Lorentz invariance in the underlying noncommutative field theory.
Closed tachyon solitons in type II string theory
Iñaki García-Etxebarria; Miguel Montero; Angel M. Uranga
2015-05-20T23:59:59.000Z
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.
Cloud of strings for radiating black holes in Lovelock gravity
Sushant G. Ghosh; Sunil D. Maharaj
2014-09-28T23:59:59.000Z
We present exact spherically symmetric null dust solutions in the third order Lovelock gravity with a string cloud background in arbitrary $N$ dimensions,. This represents radiating black holes and generalizes the well known Vaidya solution to Lovelock gravity with a string cloud in the background. We also discuss the energy conditions and horizon structures, and explicitly bring out the effect of the string clouds on the horizon structure of black hole solutions for the higher dimensional general relativity and Einstein-Gauss-Bonnet theories. It turns out that the presence of the coupling constant of the Gauss-Bonnet terms and/or background string clouds completely changes the structure of the horizon and this may lead to a naked singularity. We recover known spherically symmetric radiating models as well as static black holes in the appropriate limits.
N=2 String as a Topological Conformal Algebra
J. Gomis; H. Suzuki
1991-11-28T23:59:59.000Z
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.
Effective software testing with a string-constraint solver
Kie?un, Adam
2009-01-01T23:59:59.000Z
This dissertation presents techniques and tools for improving software reliability, by using an expressive string-constraint solver to make implementation-based testing more effective and more applicable. Concolic testing ...
LHC Olympics Workshop and String Phenomenology 2006 Conference
David Gross
2006-10-01T23:59:59.000Z
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.
Regge behavior saves String Theory from causality violations
D'Appollonio, Giuseppe; Russo, Rodolfo; Veneziano, Gabriele
2015-01-01T23:59:59.000Z
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
2015-05-12T23:59:59.000Z
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.
EK101 Engineering Light Smart Lighting
Bifano, Thomas
EK101 Engineering Light Smart Lighting Homework for 9/10 1. Make an estimate (using quantitative data) of the number of lights used on your floor of your dorm. Justify your estimate. What is the approximate total power usage (make reasonable assumptions about the relative amount of time each light is on
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
Decay of False Vacuum via Fuzzy Monopole in String Theory
Aya Kasai; Yutaka Ookouchi
2015-02-05T23:59:59.000Z
We investigate dielectric branes in false vacua in Type IIB string theory. The dielectric branes are supported against collapsing by lower energy vacua inside spherical or tube-like branes. We claim that such branes can be seeds for semi-classical (or quantum mechanical) decay of the false vacua, which makes the life-time of the false vacua shorter. Also, we discuss a topology change of a bubble corresponding to the fuzzy monopole triggered by dissolving fundamental strings.
Gauged Nambu-Jona-Lasinio model and axionic QCD string
Chi Xiong
2014-12-30T23:59:59.000Z
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.
Mellin-Barnes Representation of the Topological String
Krefl, Daniel
2015-01-01T23:59:59.000Z
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.
Non-Abelian String of a Finite Length
Monin, Sergey; Yung, Alexei
2015-01-01T23:59:59.000Z
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
2015-05-28T23:59:59.000Z
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 \
D-brane effective field theory from string field theory
Washington Taylor
2000-02-15T23:59:59.000Z
Open string field theory is considered as a tool for deriving the effective action for the massless or tachyonic fields living on D-branes. Some simple calculations are performed in open bosonic string field theory which validate this approach. The level truncation method is used to calculate successive approximations to the quartic terms \\phi^4, (A^\\mu A_\\mu)^2 and [A_\\mu, A_\
The squashed fuzzy sphere, fuzzy strings and the Landau problem
Andronache, Stefan
2015-01-01T23:59:59.000Z
We discuss the squashed fuzzy sphere, which is a projection of the fuzzy sphere onto the equatorial plane, and use it to illustrate the stringy aspects of noncommutative field theory. We elaborate explicitly how strings linking its two coincident sheets arise in terms of fuzzy spherical harmonics. In the large N limit, the matrix-model Laplacian is shown to correctly reproduce the semi-classical dynamics of these charged strings, as given by the Landau problem.
High-Energy Scattering vs Static QCD Strings
V. A. Petrov; R. A. Ryutin
2014-09-30T23:59:59.000Z
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.
Self-avoiding effective strings in lattice gauge theories
M. Caselle; F. Gliozzi
1991-11-28T23:59:59.000Z
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.
Counting Strings and Phase Transitions in 2D QCD
W. Taylor
1994-05-03T23:59:59.000Z
Several string theories related to QCD in two dimensions are studied. For each of these theories the large $N$ free energy on a (target) sphere of area $A$ is calculated. By considering theories with different subsets of the geometrical structures involved in the full QCD${}_2$ string theory, the different contributions of these structures to the string free energy are calculated using both analytic and numerical methods. The equivalence between the leading terms in the $SU(N)$ and $U(N)$ free energies is simply demonstrated from the string formulation. It is shown that when $\\Omega$-points are removed from the theory, the free energy is convergent for small and large values of $A$ but divergent in an intermediate range. Numerical results indicate that the free energy for the full QCD${}_2$ string fails to converge at the Douglas-Kazakov phase transition point. Similar results for a single chiral sector of the theory, such as has recently been studied by Cordes, Moore, and Ramgoolam, indicate that there are three distinct phases in that theory. These results indicate that from the point of view of the strong coupling phase, the phase transition in the full QCD${}_2$ string arises from the entropy of branch-point singularities.
The Wavelet Trie: Maintaining an Indexed Sequence of Strings in Compressed Space
Grossi, Roberto
2012-01-01T23:59:59.000Z
An indexed sequence of strings is a data structure for storing a string sequence that supports random access, searching, range counting and analytics operations, both for exact matches and prefix search. String sequences lie at the core of column-oriented databases, log processing, and other storage and query tasks. In these applications each string can appear several times and the order of the strings in the sequence is relevant. The prefix structure of the strings is relevant as well: common prefixes are sought in strings to extract interesting features from the sequence. Moreover, space-efficiency is highly desirable as it translates directly into higher performance, since more data can fit in fast memory. We introduce and study the problem of compressed indexed sequence of strings, representing indexed sequences of strings in nearly-optimal compressed space, both in the static and dynamic settings, while preserving provably good performance for the supported operations. We present a new data structure for...
String GUT scenarios with stabilized moduli
Blumenhagen, Ralph; Moster, Sebastian; Plauschinn, Erik [Max-Planck-Institut fuer Physik, Foehringer Ring 6, 80805 Muenchen (Germany)
2008-09-15T23:59:59.000Z
Taking into account the recently proposed poly-instanton corrections to the superpotential and combining the racetrack with a Kachru-Kallosh-Linde-Trivedi, respectively, large volume scenario in an intricate manner, we show that we gain exponential control over the parameters in an effective superpotential. This allows us to dynamically stabilize moduli such that a conventional minimal supersymmetric standard model scenario with the string scale lowered to the grand unified theory scale is realized. Depending on the cycles wrapped by the minimal supersymmetric standard model branes, two different scenarios for the hierarchy of soft masses arise. The first one is a supergravity mediated model with M{sub 3/2}{approx_equal}1 TeV while the second one features mixed anomaly supergravity mediation with M{sub 3/2}{approx_equal}10{sup 10} GeV and split supersymmetry. We also comment on dynamically lowering the scales such that the tree level cosmological constant is of the order {lambda}=(10{sup -3} eV){sup 4}.
Integrable Deformations of Strings on Symmetric Spaces
Timothy J. Hollowood; J. Luis Miramontes; David M. Schmidtt
2014-07-16T23:59:59.000Z
A general class of deformations of integrable sigma-models with symmetric space F/G target-spaces are found. These deformations involve defining the non-abelian T dual of the sigma-model and then replacing the coupling of the Lagrange multiplier imposing flatness with a gauged F/F WZW model. The original sigma-model is obtained in the limit of large level. The resulting deformed theories are shown to preserve both integrability and the equations-of-motion, but involve a deformation of the symplectic structure. It is shown that this deformed symplectic structure involves a linear combination of the original Poisson bracket and a generalization of the Faddeev-Reshetikhin Poisson bracket which we show can be re-expressed as two decoupled F current algebras. It is then shown that the deformation can be incorporated into the classical model of strings on R x F/G via a generalization of the Pohlmeyer reduction. In this case, in the limit of large sigma-model coupling it is shown that the theory becomes the relativistic symmetric space sine-Gordon theory. These results point to the existence of a deformation of this kind for the full Green-Schwarz superstring on AdS5 x S5.
Streched String with Self-Interaction at the Hagedorn Point: Spatial Sizes and Black Hole
Qian, Yachao
2015-01-01T23:59:59.000Z
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
2015-08-15T23:59:59.000Z
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.
Baker, W.S.
1991-04-01T23:59:59.000Z
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)
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
2013-05-14T23:59:59.000Z
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.
Light disappears rapidly (exponentially)
Kudela, Raphael M.
#12;#12;#12;#12;Light disappears rapidly (exponentially) with depth At the same time, the color of the light shifts #12;#12;#12;#12;· Euphotic zone plentiful light 0-100 m (about) · Dysphotic zone very, very little light 100-1000 m (about) · Aphotic zone no light below 1000 m #12;Sunlight in Water
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
Practical image based lighting
Lee, Jaemin
2003-01-01T23:59:59.000Z
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...
Tumber, A. J.
1981-01-01T23:59:59.000Z
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
1961-01-01T23:59:59.000Z
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...
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...
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.
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
A New Lorentz Violating Nonlocal Field Theory From String-Theory
Ganor, Ori J.
2009-01-01T23:59:59.000Z
hep-th/9908019]. [29] J. Polchinski, “String theory. Vol.2: Superstring theory and beyond,” [30] S. Chakravarty, K.Violating Nonlocal Field Theory From String-Theory Ori J.
Jet signals for low mass strings at the LHC
Luis A. Anchordoqui; Haim Goldberg; Satoshi Nawata; Tomasz R. Taylor
2008-04-22T23:59:59.000Z
The mass scale M_s of superstring theory is an arbitrary parameter that can be as low as few TeVs if the Universe contains large extra dimensions. We propose a search for the effects of Regge excitations of fundamental strings at LHC, in the process p p \\to \\gamma jet. The underlying parton process is dominantly the single photon production in gluon fusion, g g \\to \\gamma g, with open string states propagating in intermediate channels. If the photon mixes with the gauge boson of the baryon number, which is a common feature of D-brane quivers, the amplitude appears already at the string disk level. It is completely determined by the mixing parameter -- and it is otherwise model-(compactification-) independent. Even for relatively small mixing, 100 fb^{-1} of LHC data could probe deviations from standard model physics, at a 5\\sigma significance, for M_s as large as 3.3 TeV.
Solution of the string equations for asymmetric potentials
Patrick Waters
2015-06-22T23:59:59.000Z
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.
Clouds of strings in third-order Lovelock gravity
Sushant G. Ghosh; Uma Papnoi; Sunil D. Maharaj
2014-08-20T23:59:59.000Z
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.
Axion inflation and gravity waves in string theory
Kallosh, Renata; Sivanandam, Navin; Soroush, Masoud [Institute for Theoretical Physics, Department of Physics, Stanford University, Stanford, California 94305-4060 (United States)
2008-02-15T23:59:59.000Z
The majority of models of inflation in string theory predict an absence of measurable gravitational waves, r<<10{sup -3}. The most promising proposals for making string theoretic models that yield measurable tensor fluctuations involve axion fields with slightly broken shift symmetry. We consider such models in detail, with a particular focus on the N-flation scenario and on axion valley/natural inflation models. We find that in Calabi-Yau threefold compactifications with logarithmic Kaehler potentials K it appears to be difficult to meet the conditions required for axion inflation in the supergravity regime. However, in supergravities with an (approximately) quadratic shift-symmetric K, axion inflation may be viable. Such Kaehler potentials do arise in some string models, in specific limits of the moduli space. We describe the most promising classes of models; more detailed study will be required before one can conclude that working models exist.
Post-Holiday Holiday Shopping | 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 DeliciousPlasmaP a g e OctoberEnergyEnergy Portsmouth Notre Dame competes at NationalSiteof Energy
Theoretical Research in Cosmology, High-Energy Physics and String Theory
Ng, Y Jack; Dolan, Louise; Mersini-Houghton, Laura; Frampton, Paul
2013-07-29T23:59:59.000Z
The research was in the area of Theoretical Physics: Cosmology, High-Energy Physics and String Theory
Instability of Axions and Photons In The Presence of Cosmic Strings
Eduardo I. Guendelman; Idan Shilon
2008-10-26T23:59:59.000Z
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.
BUSCH, M.S.
2000-02-02T23:59:59.000Z
NFPA 101, section 5-9 mandates that, where required by building classification, all designated emergency egress routes be provided with adequate emergency lighting in the event of a normal lighting outage. Emergency lighting is to be arranged so that egress routes are illuminated to an average of 1.0 footcandle with a minimum at any point of 0.1 footcandle, as measured at floor level. These levels are permitted to drop to 60% of their original value over the required 90 minute emergency lighting duration after a power outage. The Plutonium Finishing Plant (PFP) has two designations for battery powered egress lights ''Emergency Lights'' are those battery powered lights required by NFPA 101 to provide lighting along officially designated egress routes in those buildings meeting the correct occupancy requirements. Emergency Lights are maintained on a monthly basis by procedure ZSR-12N-001. ''Backup Lights'' are battery powered lights not required by NFPA, but installed in areas where additional light may be needed. The Backup Light locations were identified by PFP Safety and Engineering based on several factors. (1) General occupancy and type of work in the area. Areas occupied briefly during a shiftly surveillance do not require backup lighting while a room occupied fairly frequently or for significant lengths of time will need one or two Backup lights to provide general illumination of the egress points. (2) Complexity of the egress routes. Office spaces with a standard hallway/room configuration will not require Backup Lights while a large room with several subdivisions or irregularly placed rooms, doors, and equipment will require Backup Lights to make egress safer. (3) Reasonable balance between the safety benefits of additional lighting and the man-hours/exposure required for periodic light maintenance. In some plant areas such as building 236-Z, the additional maintenance time and risk of contamination do not warrant having Backup Lights installed in all rooms. Sufficient light for egress is provided by existing lights located in the hallways.
Generalized dilaton-Maxwell cosmic string and wall solutions
John Morris
2006-08-15T23:59:59.000Z
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.
Note on Structure Formation from Cosmic String Wakes
Duplessis, Francis
2013-01-01T23:59:59.000Z
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.
A note on the string spectrum at the Hagedorn temperature
J. D. Madrigal; P. Talavera
2009-05-21T23:59:59.000Z
We discuss semi-classical string configurations at finite temperature. We find that those soliton solution in the background describing type IIA strings disappear or become divergent when we approach the Hagedorn temperature in the strong coupling regime. These findings together with a semi-classical analysis for the Hawking radiation let us to think that Hawking radiation is mainly driven by the existence of highly excited states. As by side, we check that beside the thermodynamical instability the system is dynamical unstable before reaching the Hagedorn temperature.
Coset Symmetries in Dimensionally Reduced Bosonic String Theory
N. D. Lambert; P. C. West
2001-08-02T23:59:59.000Z
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
2015-01-01T23:59:59.000Z
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.
Physical Interpretation of the 26 Dimensions of Bosonic String Theory
Frank D. Smith Jr
2002-07-15T23:59:59.000Z
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.
Kerr-NUT-AdS metrics and string theory
Chen, Wei
2008-10-10T23:59:59.000Z
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...
Kerr-NUT-AdS metrics and string theory
Chen, Wei
2009-05-15T23:59:59.000Z
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...
Sister trajectories and locality in multiloop string scattering
Carbon, S.L. (ACTA Inc., 505 N. Orlando Avenue, Mez 3, Cocoa Beach, Florida 32931 (United States))
1995-04-15T23:59:59.000Z
The multiloop corrections to the high energy behavior of four-tachyon scattering are studied in string theory. In the limit of high center-of-mass energy, [ital s][r arrow][infinity], for fixed transfer momentum squared, [ital t], we obtain the Regge behavior of the first sister'' trajectory in two-loop scattering. The multiloop-generated sisters are found to be independent of propagator twists, which are necessary for exposing tree-level sisters. The presence of these trajectories in higher order loop diagrams may be sufficient for string theory to be consistent nonperturbatively with locality.
Power Towers of String Instantons for N=1 Vacua
Ralph Blumenhagen; Maximilian Schmidt-Sommerfeld
2008-03-11T23:59:59.000Z
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.
Kerr-NUT-AdS metrics and string theory
Chen, Wei
2009-05-15T23:59:59.000Z
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...
Kerr-NUT-AdS metrics and string theory
Chen, Wei
2008-10-10T23:59:59.000Z
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...
Quantum Charged Non-Linear Nano-String and Quantum Vacuum
F. Kheirandish; M. Amooshahi
2005-07-20T23:59:59.000Z
The classical and quantum dynamic of a nonlinear chareged vibrating string and its interaction with quantum vacuum field is investigated. Some probability amplitudes for transitions between vacuum field and quantum states of the string are obtained. The effect of nonlinearity on some probability amplitudes is investigated and finally the corect equation for string containing the vacuum and radiation reaction field is obtained.
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
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
Quantization of Dyon Charge and Electric-Magnetic Duality in String Theory
Ashoke Sen
1992-09-05T23:59:59.000Z
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.
On the short string limit of the folded spinning string in AdS5 x S5
M. Beccaria; A. Tirziu
2008-10-23T23:59:59.000Z
In this paper we generalize the results of arXiv:0806.4758 to non-zero value J of angular momentum in S^5. We compute the 1-loop correction to the energy of the folded spinning string in AdS_5 x S^5 in the particular limit of slow short string approximation. In this limit the string is moving in a near-flat central region of AdS_5 slowly rotating in both AdS_5 and S^5. The one-loop correction should represent the first subleading correction to strong coupling expansion of the anomalous dimension of short gauge theory operators of the form Tr D^S Z^J in the SL(2) sector.
Holiday Plants with Toxic Misconceptions
Evens, Zabrina N; Stellpflug, Samuel J
2012-01-01T23:59:59.000Z
1999;41:394-7. the American Association of Poison ControlCenters’ National Poison 21. Kramer R. BittersweetMinnesota Hennepin Regional Poison Center, Minneapolis,
Helping make the holidays happier
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journal Article)41clothThe Bonneville Power AdministrationHawaiiEnergyFloridaOutlookOctoberHeavy Element ChemistryStartupHe!HelpHelping Make
Museum Closed for Christmas Holiday
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journal Article) |govInstrumentsmfrirtA Journey Inside the Complex andFOUR Los Phase 1MillerYi LiuAmericanMoreTowardMultiscaleMuseum
Museum Closed for Thanksgiving Holiday
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journal Article) |govInstrumentsmfrirtA Journey Inside the Complex andFOUR Los Phase 1MillerYi
Holiday Plants with Toxic Misconceptions
Evens, Zabrina N; Stellpflug, Samuel J
2012-01-01T23:59:59.000Z
the induction of emesis, decontamination, and the use oft coincide with current decontamination recommendations. 16by gastrointestinal decontamination, as 96.2% of treated
Aspects of grand unified and string phenomenology
Walker, Joel Wesley
2005-11-01T23:59:59.000Z
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...
EK101 Engineering Light Project: Evaluate Residential Lighting
Bifano, Thomas
EK101 Engineering Light Project: Evaluate Residential Lighting Compare technical and economic characteristics of three sources of residential light. Two teams of four complete the same project Engineering Light Project: Evaluate Residential Lighting Project Assignment: Evaluate current options
Scalar Perturbations in a String Inspired Inflationary Scenario
C. E. M. Batista; J. C. Fabris
1996-02-28T23:59:59.000Z
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.
The vacuum state functional of interacting string field theory
A. Ilderton
2005-06-21T23:59:59.000Z
We show that the vacuum state functional for both open and closed string field theories can be constructed from the vacuum expectation values it must generate. The method also applies to quantum field theory and as an application we give a diagrammatic description of the equivalance between Schrodinger and covariant repreresentations of field theory.
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
Renewal Strings for Cleaning Astronomical Databases Amos J. Storkey School of Informatics 5 Forrest- portion of the records potentially of inter- est to a given astronomer. We have devel- oped renewal- veys are carried out in all wavelength ranges, from high energy gamma rays to the longest wavelength ra
Renewal Strings for Cleaning Astronomical Databases Amos J. Storkey #
Storkey, Amos
Renewal Strings for Cleaning Astronomical Databases Amos J. Storkey # School of Informatics 5 portion of the records potentially of inter est to a given astronomer. We have devel oped renewal veys are carried out in all wavelength ranges, from high energy gamma rays to the longest wavelength ra
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
String Organization of Field Theories: Duality and Gauge Invariance
Y. J. Feng; C. S. Lam
1994-09-14T23:59:59.000Z
String theories should reduce to ordinary four-dimensional field theories at low energies. Yet the formulation of the two are so different that such a connection, if it exists, is not immediately obvious. With the Schwinger proper-time representation, and the spinor helicity technique, it has been shown that field theories can indeed be written in a string-like manner, thus resulting in simplifications in practical calculations, and providing novel insights into gauge and gravitational theories. This paper continues the study of string organization of field theories by focusing on the question of local duality. It is shown that a single expression for the sum of many diagrams can indeed be written for QED, thereby simulating the duality property in strings. The relation between a single diagram and the dual sum is somewhat analogous to the relation between a old- fashioned perturbation diagram and a Feynman diagram. Dual expressions are particularly significant for gauge theories because they are gauge invariant while expressions for single diagrams are not.
Grand Unification as a Bridge Between String Theory and Phenomenology
Pati, Jogesh C.
2006-06-09T23:59:59.000Z
In the first part of the talk, I explain what empirical evidence points to the need for having an effective grand unification-like symmetry possessing the symmetry SU(4)-color in 4D. If one assumes the premises of a future predictive theory including gravity--be it string/M theory or a reincarnation--this evidence then suggests that such a theory should lead to an effective grand unification-like symmetry as above in 4D, near the string-GUT-scale, rather than the standard model symmetry. Advantages of an effective supersymmetric G(224) = SU(2){sub L} x SU(2){sub R} x SU(4){sup c} or SO(10) symmetry in 4D in explaining (1) observed neutrino oscillations, (2) baryogenesis via leptogenesis, and (3) certain fermion mass-relations are noted. And certain distinguishing tests of a SUSY G(224) or SO(10)-framework involving CP and flavor violations (as in {mu} {yields} e{gamma}, {tau} {yields} {mu}{gamma}, edm's of the neutron and the electron) as well as proton decay are briefly mentioned. Recalling some of the successes we have had in our understanding of nature so far, and the current difficulties of string/M theory as regards the large multiplicity of string vacua, some comments are made on the traditional goal of understanding vis a vis the recently evolved view of landscape and anthropism.
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
Effective string theory description of the interface free energy
M. Billo; M. Caselle; L. Ferro; M. Hasenbusch; M. Panero
2007-10-09T23:59:59.000Z
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
Brane cosmic string compactification in Brans-Dicke theory
Abdalla, M. C. B.; Hoff da Silva, J. M. [Instituto de Fisica Teorica, Universidade Estadual Paulista, Rua Pamplona 145 01405-900 Sao Paulo, SP (Brazil); Guimaraes, M. E. X. [Departamento de Matematica, Universidade de Brasilia, Asa Norte 70910-900, Brasilia-DF (Brazil)
2007-04-15T23:59:59.000Z
We investigate an alternative compactification of extra dimensions using local cosmic string in the Brans-Dicke gravity framework. In the context of dynamical systems it is possible to show that there exist a stable field configuration for the Einstein-Brans-Dicke equations. We explore the analogies between this particular model and the Randall-Sundrum scenario.
Introduction to conformal field theory and string theory
Dixon, L.J.
1989-12-01T23:59:59.000Z
These lectures are meant to provide a brief introduction to conformal field theory (CFT) and string theory for those with no prior exposure to the subjects. There are many excellent reviews already available, and most of these go in to much more detail than I will be able to here. 52 refs., 11 figs.
Kazuyuki Furuuchi
2008-06-30T23:59:59.000Z
Closed string field theory is constructed by stochastically quantizing a matrix model for Polyakov loops that describes phases of a large N gauge theory at finite temperature. Coherent states in this string field theory describes winding string condensation which has been expected to cause a topology change from thermal AdS geometry to AdS-Schwarzschild black hole geometry. D-branes in this closed string field theory is also discussed. Slightly extended version of a talk given at CosPA 2007, Nov.13-15, Taipei, Taiwan.
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
Kevin Cahill
2011-10-10T23:59:59.000Z
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.
Automatic lighting controls demonstration
Rubinstein, F.; Verderber, R.
1990-03-01T23:59:59.000Z
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.
CONNECTED LIGHTING SYSTEMS MEETING
Broader source: Energy.gov [DOE]
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...
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
Shaw-Meadow, N.
2011-01-01T23:59:59.000Z
? 1 ? ?The cheapest 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... consumption ? ENTER LED ? Current LED technology is ready for the main event; Let?s Play, Too! Roadway Lighting: Goals ESL-KT-11-11-57 CATEE 2011, Dallas, Texas, Nov. 7 ? 9, 2011 ? 3 ? White LED: Debuted in the mid 90s Shuji Nakamura, Nichia...
Lighting and Daylight Harvesting
Bos, J.
2011-01-01T23:59:59.000Z
glazings are allowing more opportunities for light without losing as much in added HVAC load. Daylight Harvesting Parts and Pieces 2. Dimmable light source i.e. Incandescent, Fluorescent and LED commonly. Metal Halide is not appropriate because...The firm was founded 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...
Shaw-Meadow, N.
2011-01-01T23:59:59.000Z
? 1 ? ?The cheapest 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... consumption ? ENTER LED ? Current LED technology is ready for the main event; Let?s Play, Too! Roadway Lighting: Goals ESL-KT-11-11-57 CATEE 2011, Dallas, Texas, Nov. 7 ? 9, 2011 ? 3 ? White LED: Debuted in the mid 90s Shuji Nakamura, Nichia...
AIRPORT LIGHTING Session Highlights
Minnesota, University of
AIRPORT LIGHTING Session Highlights In May 2002, the Airport Technical Assistance Program, also known as AirTAP, sponsored three airport-lighting training sessions at different locations in Minnesota information on airport lighting and navigational aid equipment selection, funding, maintenance, and operation
Light Rail Transit Strengthening
Minnesota, University of
Light Rail Transit Improving mobility Easing congestion Strengthening our communities Central Corridor Communicating to the Public During Major Construction May 25, 2011 #12;2 Light Rail Transit;Light Rail Transit Central Corridor Route and Stations 3 · 18 new stations · 9.8 miles of new double
Light emitting device comprising phosphorescent materials for white light generation
Thompson, Mark E.; Dapkus, P. Daniel
2014-07-22T23:59:59.000Z
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...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
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.......
Gauge field, strings, solitons, anomalies and the speed of life
Niemi, Antti J
2014-01-01T23:59:59.000Z
It's been said that "mathematics is biology's next microscope, only better; biology is mathematics' next physics, only better". Here we aim for something even better. We try to combine mathematical physics and biology into a picoscope of life. For this we merge techniques which have been introduced and developed in modern mathematical physics, largely by Ludvig Faddeev to describe objects such as solitons and Higgs and to explain phenomena such as anomalies in gauge fields. We propose a synthesis that can help to resolve the protein folding problem, one of the most important conundrums in all of science. We apply the concept of gauge invariance to scrutinize the extrinsic geometry of strings in three dimensional space. We evoke general principles of symmetry in combination with Wilsonian universality and derive an essentially unique Landau-Ginzburg energy that describes the dynamics of a generic string-like configuration in the far infrared. We observe that the energy supports topological solitons, that perta...
Aspects of noncommutativity in field theory, strings and membranes
Kuldeep Kumar
2008-12-30T23:59:59.000Z
We study certain aspects of noncommutativity in field theory, strings and membranes. We analyse the dynamics of an open membrane whose boundary is attached to p-branes. Noncommutative features of the boundary string coordinates are revealed by algebraic consistency arguments. Next, we derive Seiberg-Witten-type maps relating currents and their divergences in nonabelian U(N) noncommutative gauge theory with the corresponding expressions in the ordinary (commutative) description. We then exploit these maps to obtain the O(\\theta) structure of the commutator anomalies in noncommutative electrodynamics. Finally, we discuss the issue of violation of Lorentz invariance in noncommutative gauge theories by explicitly deriving, following a Noether-like approach, the criteria for preserving Poincare invariance. We also study general (deformed) conformal-Poincare (Galilean) symmetries consistent with relativistic (nonrelativistic) canonical noncommutative spaces.
Generalized Duality and Singular Strings in Higher Dimensions
I. Bars; K. Sfetsos
1991-10-24T23:59:59.000Z
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.
Gamma-ray bursts, axion emission and string theory dilaton
O. Bertolami
1999-01-14T23:59:59.000Z
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.
Light and Energy -Daylight measurements
Light and Energy - Daylight measurements #12;Light and Energy - Daylight measurements Authors: Jens;3 Title Light and Energy Subtitle Daylight measurements Authors Jens Christoffersen, Ásta Logadóttir
Stability of false vacuum in supersymmetric theories with cosmic strings
Kumar, Brijesh; Yajnik, Urjit A. [Department of Physics, Indian Institute of Technology, Bombay, Mumbai - 400076 (India)
2009-03-15T23:59:59.000Z
We study the stability of supersymmetry breaking vacuum in the presence of cosmic strings arising in the messenger sector. For certain ranges of the couplings, the desired supersymmetry breaking vacua become unstable against decay into phenomenologically unacceptable vacua. This sets constraints on the range of allowed values of the coupling constants appearing in the models and more generally on the chosen dynamics of gauge symmetry breaking.
Boundary String Field Theory of the DDbar System
Kraus, P; Kraus, Per; Larsen, Finn
2001-01-01T23:59:59.000Z
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.
Effective Supergravity from the Weakly Coupled HeteroticString
Gaillard, Mary K.
2005-05-01T23:59:59.000Z
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.
Vacuum Polarization on the Schwarzschild Metric with a Cosmic String
Adrian C. Ottewill; Peter Taylor
2010-06-30T23:59:59.000Z
We consider the problem of the renormalization of the vacuum polarization in a symmetry space-time with axial but not spherical symmetry, Schwarzschild space-time threaded by an infinite straight cosmic string. Unlike previous calculations, our framework to compute the renormalized vacuum polarization does not rely on special properties of Legendre functions, but rather has been developed in a way that we expect to be applicable to Kerr space-time.
Hamilton-Jacobi formalism for string gas thermodynamics
Anosh Joseph; S. G. Rajeev
2009-03-27T23:59:59.000Z
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.
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
Using QECBs for Street Lighting Upgrades: Lighting the Way to...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
QECBs for Street Lighting Upgrades: Lighting the Way to Lower Energy Bills in San Diego Using QECBs for Street Lighting Upgrades: Lighting the Way to Lower Energy Bills in San...
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...
Thermal duality and gravitational collapse in heterotic string theories
Michael Hewitt
2015-07-04T23:59:59.000Z
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.
Gauge field, strings, solitons, anomalies and the speed of life
Antti J. Niemi
2014-07-05T23:59:59.000Z
It's been said that "mathematics is biology's next microscope, only better; biology is mathematics' next physics, only better". Here we aim for something even better. We try to combine mathematical physics and biology into a picoscope of life. For this we merge techniques which have been introduced and developed in modern mathematical physics, largely by Ludvig Faddeev to describe objects such as solitons and Higgs and to explain phenomena such as anomalies in gauge fields. We propose a synthesis that can help to resolve the protein folding problem, one of the most important conundrums in all of science. We apply the concept of gauge invariance to scrutinize the extrinsic geometry of strings in three dimensional space. We evoke general principles of symmetry in combination with Wilsonian universality and derive an essentially unique Landau-Ginzburg energy that describes the dynamics of a generic string-like configuration in the far infrared. We observe that the energy supports topological solitons, that pertain to an anomaly in the manner how a string is framed around its inflection points. We explain how the solitons operate as modular building blocks from which folded proteins are composed. We describe crystallographic protein structures by multi-solitons with experimental precision, and investigate the non-equilibrium dynamics of proteins under varying temperature. We simulate the folding process of a protein at in vivo speed and with close to pico-scale accuracy using a standard laptop computer: With pico-biology as mathematical physics' next pursuit, things can only get better.
Interpolating the Coulomb Phase of Little String Theory
Ying-Hsuan Lin; Shu-Heng Shao; Yifan Wang; Xi Yin
2015-02-05T23:59:59.000Z
We study up to 8-derivative terms in the Coulomb branch effective action of (1,1) little string theory, by collecting results of 4-gluon scattering amplitudes from both perturbative 6D super-Yang-Mills theory up to 4-loop order, and tree-level double scaled little string theory (DSLST). In previous work we have matched the 6-derivative term from the 6D gauge theory to DSLST, indicating that this term is protected on the entire Coulomb branch. The 8-derivative term, on the other hand, is unprotected. In this paper we compute the 8-derivative term by interpolating from the two limits, near the origin and near the infinity on the Coulomb branch, numerically from SU(k) SYM and DSLST respectively, for k=2,3,4,5. We discuss the implication of this result on the UV completion of 6D SYM as well as the strong coupling completion of DSLST. We also comment on analogous interpolating functions in the Coulomb phase of circle-compactified (2,0) little string theory.
Experiences with string matching on the Fermi Architecture
Tumeo, Antonino; Secchi, Simone; Villa, Oreste
2011-02-25T23:59:59.000Z
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.
Field Definitions, Spectrum and Universality in Effective String Theories
N. D. Hari Dass; Peter Matlock
2006-12-28T23:59:59.000Z
It is shown, by explicit calculation, that the third-order terms in inverse string length in the spectrum of the effective string theories of Polchinski and Strominger are also the same as in Nambu-Goto theory, in addition to the universal Luescher terms. While the Nambu-Goto theory is inconsistent outside the critical dimension, the Polchinski-Strominger theory is by construction consistent for any space-time dimension. In the analysis of the spectrum, care is taken not to use any field redefinition, as it is felt that this has the potential to obscure important points. Nevertheless, as field redefinition is an important tool and the definition of the field should be made precise, a careful analysis of the choice of field definition leading to the terms in the action is also presented. Further, it is shown how a choice of field definition can be made in a systematic way at higher orders. To this end the transformation of measure involved is calculated, in the context of effective string theory, and thereby a quantum evaluation made of equivalence of theories related by a field redefinition. It is found that there are interesting possibilities resulting from a redefinition of fluctuation field.
Dangerous Angular KK/Glueball Relics in String Theory Cosmology
J. F. Dufaux; L. Kofman; M. Peloso
2008-07-07T23:59:59.000Z
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.
CERN Winter School on Supergravity, Strings, and Gauge Theory 2010
None
2011-10-06T23:59:59.000Z
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
Spiky strings and giant magnons on S5
M. Kruczenski; J. Russo; A. A. Tseytlin
2006-07-14T23:59:59.000Z
Recently, classical solutions for strings moving in AdS5 x S5 have played an important role in understanding the AdS/CFT correspondence. A large set of them were shown to follow from an ansatz that reduces the solution of the string equations of motion to the study of a well-known integrable 1-d system known as the Neumann-Rosochatius (NR) system. However, other simple solutions such as spiky strings or giant magnons in S5 were not included in the NR ansatz. We show that, when considered in the conformal gauge, these solutions can be also accomodated by a version of the NR-system. This allows us to describe in detail a giant magnon solution with two additional angular momenta and show that it can be interpreted as a superposition of two magnons moving with the same speed. In addition, we consider the spin chain side and describe the corresponding state as that of two bound states in the infinite SU(3) spin chain. We construct the Bethe ansatz wave function for such bound state.
Conformal Transformations and Strings for an Accelerating Quark-Antiquark Pair in AdS3
Shijong Ryang
2014-12-08T23:59:59.000Z
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.
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
2013-01-01T23:59:59.000Z
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
2014-04-07T23:59:59.000Z
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.
Lighting the Night: Technology, Urban Life and the Evolution of Street Lighting [Light in Place
Holden, Alfred
1992-01-01T23:59:59.000Z
Electrical 16. "Highway Lighting by So dium Vapor Lamps,"Possibilities of Street: Lighting Improve ments," TheLaunches Broad Street Lighting Promotion Campaign," The
Foundations and Light Compass Foundations and Light Compass
Wong, Jennifer L.
Foundations and Light Compass Case Study Foundations and Light Compass Case Study Jennifer L. WongQuantitative Sensor--centric Designcentric Design Light CompassLight Compass Models and Abstractions Contaminant Transport Marine Microorganisms Ecosystems, Biocomplexity What is a Light Compass?What is a Light
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
Resonant acoustic transducer and driver system for a well drilling string communication system
Chanson, Gary J. (Weston, MA); Nicolson, Alexander M. (Concord, MA)
1981-01-01T23:59:59.000Z
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.
On Rotating and Oscillating Four-Spin Strings in AdS5 X S5
Kamal L. Panigrahi; Pabitra M. Pradhan
2012-10-26T23:59:59.000Z
We study rigidly rotating strings in AdS5 X S5 background with one spin along AdS5 and three angular momenta along S5. We find dispersion relations among various charges and interpret them as giant magnon and spiky string solutions in various limits. Further we present an example of oscillating string which oscillates in the radial direction of the AdS5 and at the same time rotates in S5.
On Rotating and Oscillating Four-Spin Strings in AdS5 X S5
Panigrahi, Kamal L
2012-01-01T23:59:59.000Z
We study rigidly rotating strings in AdS5 X S5 background with one spin along AdS5 and three angular momenta along S5. We find dispersion relations among various charges and interpret them as giant magnon and spiky string solutions in various limits. Further we present an example of oscillating string which oscillates in the radial direction of the AdS5 and at the same time rotates in S5.
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
B polarization of the cosmic microwave background as a tracer of strings
Seljak, Uros [Department of Physics, Princeton University, Princeton New Jersey 08544 (United States); International Center for Theoretical Physics, Trieste (Italy); Slosar, Anze [Faculty of Mathematics and Physics, University of Ljubljana (Slovenia)
2006-09-15T23:59:59.000Z
String models can produce successful inflationary scenarios in the context of brane collisions, and in many of these models cosmic strings may also be produced. In scenarios such as Kachru-Kallosh-Linde-Maldacena-McAllister-Trivedi (KKLMMT) scenario the string contribution is naturally predicted to be well below the inflationary signal for cosmic microwave background (CMB) temperature anisotropies, in agreement with the existing limits. We find that for B type polarization of CMB the situation is reversed and the dominant signal comes from vector modes generated by cosmic strings, which exceeds the gravity wave signal from both inflation and strings. The signal can be detected for a broad range of parameter space; future polarization experiments may be able to detect the string signal down to the string tension G{mu}=10{sup -9}, although foregrounds and lensing are likely to worsen these limits. We argue that the optimal scale to search for the string signature is at l{approx}1000, but in models with high optical depth the signal from reionization peak at large scales is also significant. The shape of the power spectrum allows one to distinguish the string signature from the gravity waves from inflation, but only with a sufficiently high angular resolution experiment.
Lectures on D-branes, tachyon condensation, and string field theory
Washington Taylor
2003-01-15T23:59:59.000Z
These lectures provide an introduction to the subject of tachyon condensation in the open bosonic string. The problem of tachyon condensation is first described in the context of the low-energy Yang-Mills description of a system of multiple D-branes, and then using the language of string field theory. An introduction is given to Witten's cubic open bosonic string field theory. The Sen conjectures on tachyon condensation in open bosonic string field theory are introduced, and evidence confirming these conjectures is reviewed.
Energy Distribution of a Black Hole Solution in Heterotic String Theory
I. Radinschi
2003-02-12T23:59:59.000Z
We calculate the energy distribution of a charged black hole solution in heterotic string theory in the M{\\o}ller prescription.
National Synchrotron Light Source
BNL
2009-09-01T23:59:59.000Z
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.
High efficiency incandescent lighting
Bermel, Peter; Ilic, Ognjen; Chan, Walker R.; Musabeyoglu, Ahmet; Cukierman, Aviv Ruben; Harradon, Michael Robert; Celanovic, Ivan; Soljacic, Marin
2014-09-02T23:59:59.000Z
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.
New Light Sources for Tomorrow's Lighting Designs
Krailo, D. A.
1986-01-01T23:59:59.000Z
for headlam~for the automotive industry, has led to the development of halo en capsule lamps for general lighting. The original90-watt family PAR 38 lamps using tungsten halogen capsules produces the sa amount of useful light in the beam as a I50-watt PAR... with similar benefi . Each of these tungsten halogen capsule PAR wattages are av ilable in narrow spot, spot, and flood beam patterns. The most recent developments in the PAR halogen psule family include two entirely new lamp designs: PAR 20 od PAR 30...
Maxey, L Curt [ORNL
2008-01-01T23:59:59.000Z
Hybrid solar lighting systems focus highly concentrated sunlight into a fiber optic bundle to provide sunlight in rooms without windows or conventional skylights.
Robert Geroch
2010-05-10T23:59:59.000Z
It is argued that special relativity remains a viable physical theory even when there is permitted signals traveling faster than light.
Broader source: Energy.gov [DOE]
Presentation covers total light management, and is given at the Spring 2010 Federal Utility Partnership Working Group (FUPWG) meeting in Providence, Rhode Island.
Broader source: Energy.gov [DOE]
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.
Broader source: Energy.gov [DOE]
Presentation covers the Lighting Technology Panel for the Federal Utility Partnership Working Group (FUPWG) meeting, held on November 18-19, 2009.
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
Explosively pumped laser light
Piltch, Martin S. (Los Alamos, NM); Michelotti, Roy A. (Los Alamos, NM)
1991-01-01T23:59:59.000Z
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.
Efficient Aho-Corasick String Matching on Emerging Multicore Architectures
Tumeo, Antonino; Villa, Oreste; Secchi, Simone; Chavarría-Miranda, Daniel
2013-12-12T23:59:59.000Z
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.
Size scaling of self gravitating polymers and strings
Shoichi Kawamoto; Toshihiro Matsuo
2015-06-03T23:59:59.000Z
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.
String black hole: Can it be a particle accelerator ?
Sharmanthie Fernando
2014-08-21T23:59:59.000Z
In this paper we have studied the possibility of the center-of-mass energy of two particles colliding near the horizon of a static charged black hole in string theory. Various cases corresponding to the electric charge and the angular momentum of the particles were considered. The studies were done for the general black hole as well as for the extreme black hole. There were two scenarios where the center-of-mass energy reach very large values if the appropriate properties of the particles are chosen.
Size scaling of self gravitating polymers and strings
Kawamoto, Shoichi
2015-01-01T23:59:59.000Z
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.
System and method for damping vibration in a drill string
Wassell, Mark Ellsworth; Turner, William Evans; Burgess, Daniel E; Perry, Carl Allison
2014-03-04T23:59:59.000Z
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)
2008-05-27T23:59:59.000Z
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)
2007-05-22T23:59:59.000Z
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)
2011-08-16T23:59:59.000Z
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)
2012-08-14T23:59:59.000Z
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.
Exact results on ABJ theory and the refined topological string
Masazumi Honda; Kazumi Okuyama
2014-07-22T23:59:59.000Z
We study the partition function of the ABJ theory, which is the N=6 superconformal Chern-Simons matter theory with gauge group U(N)xU(N+M) and Chern-Simons levels (k,-k). We exactly compute the ABJ partition function on a three sphere for various k, M and N via the Fermi gas approach. By using these exact data, we show that the ABJ partition function is completely determined by the refined topological string on local P^1 x P^1, including membrane instanton effects in the M-theory dual.
On higher spins and the tensionless limit of String Theory
A. Sagnotti; M. Tsulaia
2004-01-09T23:59:59.000Z
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.
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
Fisher, Kathleen
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
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
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 versus cost - Power Electronic Drives for CFL and LED light sources to achieve dimmable operation - Basic
The anomaly-free quantization of two-dimensional relativistic string. I
S. N. Vergeles
1998-12-21T23:59:59.000Z
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.
An Efficient Index Structure for String Databases Tamer Kahveci Ambuj K. Singh
Kahveci, Tamer
are genetic data, web data, and event se- quences. Since the size of such databases grows exponentially online access and search capabilities. String data applications generally involve very large databasesAn Efficient Index Structure for String Databases Tamer Kahveci Ambuj K. Singh Department
DRILL-STRING NONLINEAR DYNAMICS ACCOUNTING FOR DRILLING FLUID T. G. Ritto
Boyer, Edmond
;1. INTRODUCTION A drill-string is a slender structure used in oil wells to penetrate the soil in search of oilDRILL-STRING NONLINEAR DYNAMICS ACCOUNTING FOR DRILLING FLUID T. G. Ritto R. Sampaio thiagoritto Descartes, 77454 Marne-la-Vallée, France Abstract. The influence of the drilling fluid (or mud) on the drill
Wavelet domain Bayesian denoising of string signal in the cosmic microwave background
D. K. Hammond; Y. Wiaux; P. Vandergheynst
2009-04-27T23:59:59.000Z
An algorithm is proposed for denoising the signal induced by cosmic strings in the cosmic microwave background (CMB). A Bayesian approach is taken, based on modeling the string signal in the wavelet domain with generalized Gaussian distributions. Good performance of the algorithm is demonstrated by simulated experiments at arcminute resolution under noise conditions including primary and secondary CMB anisotropies, as well as instrumental noise.
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
Kalb-Ramond axion production in anisotropic string cosmologies Ruth Durrer1
Durrer, Ruth
Kalb-Ramond axion production in anisotropic string cosmologies Ruth Durrer1 and Mairi Sakellariadou the energy spectra for massless Kalb-Ramond axions in four-dimensional anisotropic string cosmological models). In contrast, the axion energy spectra were found to be diverging at large scales, red spectra, leading to very
White light velocity interferometer
Erskine, D.J.
1999-06-08T23:59:59.000Z
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)
1998-11-03T23:59:59.000Z
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.
Demonstration Assessment of Light-Emitting Diode (LED) Roadway Lighting
None
2009-11-01T23:59:59.000Z
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.
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...
Gauge/String-Gravity Duality and Froissart Bound
Kyungsik Kang
2004-10-16T23:59:59.000Z
The gauge/string-gravity duality correspondence opened renewed hope and possibility to address some of the fundamental and non-perturbative QCD problems in particle physics, such as hadron spectrum and Regge behavior of the scattering amplitude at high energies. One of the most fundamental and long-standing problem is the high energy behavior of total cross-sections. According to a series of exhaustive tests by the COMPETE group, (1). total cross-sections have a universal Heisenberg behavior in energy corresponding to the maximal energy behavior allowed by the Froissart bound, i.e., $A + B ln^2 (s/s_0)$ with $B \\sim 0.32 mb$ and $s_0 \\sim 34.41 GeV^2$ for all reactions, and (2). the factorization relation among $\\sigma_{pp, even}, \\sigma_{\\gamma p}, and \\sigma_{\\gamma \\gamma}$ is well satisfied by experiments. I discuss the recent interesting application of the gauge/string-gravity duality of $AdS/CFT$ correspondence with a deformed background metric so as to break the conformal symmetry that can lead to the Heisenberg behavior of rising total cross-sections, and present some preliminary results on the high energy QCD from Planckian scattering in $AdS$ and black-hole production.
String Theory clues for the low-$\\ell$ CMB ?
N. Kitazawa; A. Sagnotti
2014-12-01T23:59:59.000Z
"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
2011-06-28T23:59:59.000Z
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
2015-01-01T23:59:59.000Z
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.
Columbia Water and Light- HVAC and Lighting Efficiency Rebates
Broader source: Energy.gov [DOE]
Columbia Water and Light (CWL) offers rebates to its commercial and industrial customers for the purchase of high efficiency HVAC installations and efficient lighting. Incentives for certain...
Reading Municipal Light Department- Business Lighting Rebate Program
Broader source: Energy.gov [DOE]
Reading Municipal Light Department (RMLD) offers incentives for non-residential customers to install energy efficient lights and sensors in existing facilities. In addition to rebates for the...
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....
Sandia Energy - (Lighting and) Solid-State Lighting: Science...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
on the third and upcoming revolution (illumination). Topics cover the basics of light-emitting diode (LED) operation; a 200-year history of lighting technology; the importance of...
Sandia National Laboratories: (Lighting and) Solid-State Lighting...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
on the third and upcoming revolution (illumination). Topics cover the basics of light-emitting diode (LED) operation; a 200-year history of lighting technology; the importance of...
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...
Alexander Milov
2008-12-21T23:59:59.000Z
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)
Engineering Society says that illumination of 30 to 50 footcandles is adequate for most home, office, and school work. Efficacy: the ratio of light output from a lamp to the...
National Synchrotron Light Source
None
2010-01-08T23:59:59.000Z
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
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 ...
Broader source: Energy.gov [DOE]
SSL technology is evolving from sources focused on a one-dimensional commodity (i.e. producing light) into multi-function devices that also produce and exchange data. SSL’s microelectronic nature...
Lighting and Daylight Harvesting
Bos, J.
2011-01-01T23:59:59.000Z
is cost, lack of flexibility Market is trending away from these. The ballasts are higher cost without returning information. Lutron, Advance, Tridonics all make systems using these Daylight Harvesting Parts and Pieces 4. Smart Protocol.... Currently Walmart, Home Depot, Sam?s Club all use a switching variant with multitube fluorescent hi bay fixtures Control of Electric Light 1. First and foremost windows, skylights, and clerestories. Maximize all potential for free light. New...
Solid state lighting component
Yuan, Thomas; Keller, Bernd; Ibbetson, James; Tarsa, Eric; Negley, Gerald
2010-10-26T23:59:59.000Z
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
2012-07-10T23:59:59.000Z
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
Christensen, M.
1981-01-01T23:59:59.000Z
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...
Lingampalli, Nithya
2013-01-01T23:59:59.000Z
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
Higher order light propagation volumes
Martin, Timothy Ly; Martin, Timothy Ly
2012-01-01T23:59:59.000Z
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
Hartman, C W; Reisman, D B; McLean, H S; Thomas, J
2007-05-30T23:59:59.000Z
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.
July 18, 2012 Using QECBs for Street Lighting Upgrades
lighting technologies (e.g. light-emitting diodes, induction lighting) can reduce street light energy
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.
GATEWAY Demonstrations: LED Street Lighting
None
2008-12-01T23:59:59.000Z
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.
CONSTRAINING THE STRING GAUGE FIELD BY GALAXY ROTATION CURVES AND PERIHELION PRECESSION OF PLANETS
Cheung, Yeuk-Kwan E.; Xu Feng, E-mail: cheung@nju.edu.cn [Department of Physics, Nanjing University, 22 Hankou Road, Nanjing 210093 (China)
2013-09-01T23:59:59.000Z
We discuss a cosmological model in which the string gauge field coupled universally to matter gives rise to an extra centripetal force and will have observable signatures on cosmological and astronomical observations. Several tests are performed using data including galaxy rotation curves of 22 spiral galaxies of varied luminosities and sizes and perihelion precessions of planets in the solar system. The rotation curves of the same group of galaxies are independently fit using a dark matter model with the generalized Navarro-Frenk-White (NFW) profile and the string model. A remarkable fit of galaxy rotation curves is achieved using the one-parameter string model as compared to the three-parameter dark matter model with the NFW profile. The average {chi}{sup 2} value of the NFW fit is 9% better than that of the string model at a price of two more free parameters. Furthermore, from the string model, we can give a dynamical explanation for the phenomenological Tully-Fisher relation. We are able to derive a relation between field strength, galaxy size, and luminosity, which can be verified with data from the 22 galaxies. To further test the hypothesis of the universal existence of the string gauge field, we apply our string model to the solar system. Constraint on the magnitude of the string field in the solar system is deduced from the current ranges for any anomalous perihelion precession of planets allowed by the latest observations. The field distribution resembles a dipole field originating from the Sun. The string field strength deduced from the solar system observations is of a similar magnitude as the field strength needed to sustain the rotational speed of the Sun inside the Milky Way. This hypothesis can be tested further by future observations with higher precision.
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...
Sandia Energy - White Light Creation Architectures
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
White Light Creation Architectures Home Energy Research EFRCs Solid-State Lighting Science EFRC White Light Creation Architectures White Light Creation ArchitecturesAlyssa...
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
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
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
Smart Lighting: A Second Wave in Solid State Lighting?
Salama, Khaled
Smart Lighting: A Second Wave in Solid State Lighting? OIDA Conference on Green Photonics Bob Karlicek Director, Smart Lighting Engineering Research Center Rensselaer Polytechnic Institute June 2010 #12;2 Outline · The First Wave of Solid State Lighting · Complex Dynamics in the Supply Chain · What
Qi Liu; Norman H. Christ; Chulwoo Jung
2012-06-01T23:59:59.000Z
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.
C. Pajares; D. Sousa; R. A. Vázquez
2000-05-31T23:59:59.000Z
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.
Sustainability of multi-field inflation and bound on string scale
Jinn-Ouk Gong
2009-02-11T23:59:59.000Z
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
2007-09-28T23:59:59.000Z
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.
Z2 electric strings and center vortices in SU(2) lattice gauge theory
M. I. Polikarpov; P. V. Buividovich
2008-01-01T23:59:59.000Z
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.
Airy Equation for the Topological String Partition Function in a Scaling Limit
Alim, Murad; Zhou, Jie
2015-01-01T23:59:59.000Z
We use the polynomial formulation of the holomorphic anomaly equations governing perturbative topological string theory to derive the free energies in a scaling limit to all orders in perturbation theory for any Calabi-Yau threefold. The partition function in this limit satisfies an Airy differential equation in a rescaled topological string coupling. One of the two solutions of this equation gives the perturbative expansion and the other solution provides geometric hints of the non-perturbative structure of topological string theory. Both solutions can be expanded naturally around strong coupling.
Wave and quantum properties of peptide strings: defining a helix in spacetime
Razvan Tudor Radulescu
2009-04-25T23:59:59.000Z
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.
CP Violation and Dilaton Stabilization in Heterotic String Models
S. Khalil; O. Lebedev; S. Morris
2002-04-26T23:59:59.000Z
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
2002-01-01T23:59:59.000Z
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.
Nonreciprocal wave scattering on nonlinear string-coupled oscillators
Lepri, Stefano, E-mail: stefano.lepri@isc.cnr.it [Consiglio Nazionale delle Ricerche, Istituto dei Sistemi Complessi, via Madonna del Piano 10, I-50019 Sesto Fiorentino (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino (Italy); Pikovsky, Arkady [Department of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Str 24/25, Potsdam (Germany); Department of Control Theory, Nizhni Novgorod State University, Gagarin Av. 23, 606950, Nizhni Novgorod (Russian Federation)
2014-12-01T23:59:59.000Z
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.
Size scaling of self gravitating polymers and strings
Shoichi Kawamoto; Toshihiro Matsuo
2015-08-04T23:59:59.000Z
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.
Birth of the Universe from the Landscape of String Theory
Archil Kobakhidze; Laura Mersini-Houghton
2004-10-20T23:59:59.000Z
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 $\\Lambda_s \\simeq (\\frac{s \\pi}{l_p N})^2$, $s = 1,2,..$.
Anthropic reasoning in multiverse cosmology and string theory
Steven Weinstein
2006-06-08T23:59:59.000Z
Anthropic arguments in multiverse cosmology and string theory rely on the weak anthropic principle (WAP). We show that the principle, though ultimately a tautology, is nevertheless ambiguous. It can be reformulated in one of two unambiguous ways, which we refer to as WAP_1 and WAP_2. We show that WAP_2, the version most commonly used in anthropic reasoning, makes no physical predictions unless supplemented by a further assumption of "typicality", and we argue that this assumption is both misguided and unjustified. WAP_1, however, requires no such supplementation; it directly implies that any theory that assigns a non-zero probability to our universe predicts that we will observe our universe with probability one. We argue, therefore, that WAP_1 is preferable, and note that it has the benefit of avoiding the inductive overreach characteristic of much anthropic reasoning.
String compactification, QCD axion and axion-photon-photon coupling
Kang-Sin Choi; Ian-Woo Kim; Jihn E. Kim
2007-01-13T23:59:59.000Z
It is pointed out that there exist a few problems to be overcome toward an observable sub-eV QCD axion in superstring compactification. We give a general expression for the axion decay constant. For a large domain wall number $N_{DW}$, the axion decay constant can be substantially lowered from a generic value of a scalar singlet VEV. The Yukawa coupling structure in the recent $Z_{12-I}$ model is studied completely, including the needed nonrenormalizable terms toward realistic quark and lepton masses. In this model we find an approximate global symmetry and vacuum so that a QCD axion results but its decay constant is at the GUT scale. The axion-photon-photon coupling is calculated for a realistic vacuum satisfying the quark and lepton mass matrix conditions. It is the first time calculation of $c_{a\\gamma\\gamma}$ in realistic string compactifications: $c_{a\\gamma\\gamma}={5/3}-1.93\\simeq -0.26$.
Nonreciprocal wave scattering on nonlinear string-coupled oscillators
Stefano Lepri; Arkady Pikovsky
2014-10-29T23:59:59.000Z
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.
Strings on AdS Wormholes and Nonsingular Black Holes
H. Lu; Justin F. Vazquez-Poritz; Zhibai Zhang
2014-10-22T23:59:59.000Z
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.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Eifert, Till; Nachman, Benjamin
2015-04-01T23:59:59.000Z
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
Pupillary efficient lighting system
Berman, Samuel M. (San Francisco, CA); Jewett, Don L. (Mill Valley, CA)
1991-01-01T23:59:59.000Z
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.
Lindsey, Jonathan S. (Raleigh, NC)
2002-01-01T23:59:59.000Z
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).
Glennys R. Farrar
1997-07-25T23:59:59.000Z
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.
Valentine, Paul; Edwards, Doreen D.; Walker, Jr., William John; Slack, Lyle H.; Brown, Wayne Douglas; Osborne, Cathy; Norton, Michael; Begley, Richard
2010-05-18T23:59:59.000Z
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
1990-01-01T23:59:59.000Z
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)
LIGHTING 101 1. Common terminology
California at Davis, University of
SECTION 3 LIGHTING 101 1. Common terminology 2. Sources & luminaires 3. Controls #12;SECTION 3SECTION 3 DISCUSSION: COMMON LIGHTING TERMINOLOGY 1. What are the definitions of the following lighting terms? 2. Do you use these terms in professional practice? 3. What other lighting terminology do you use
LIGHTING 101 1. Common terminology
California at Davis, University of
LIGHTING 101 1. Common terminology 2. Sources and luminaires 3. Controls #12;SECTION 2 DISCUSSION: COMMON LIGHTING TERMINOLOGY 1. What are the definitions of the following lighting terms? 2. Do you use these terms in professional practice? 3. What other lighting terminology do you use on the job? SLIDE 14
Hart, A. L.
1982-01-01T23:59:59.000Z
. The mean light output of an I-Line lamp is about 50% greater than the corresponding wattage mercury lamp. A "Watt-Miser RlI I-Line Multi-Vapor lamp is also available (MV 325/1/) saving about 70 watts when operated only on a 400 w CW/CWA mercury ballast... on proper MV and HPS ballasts. High Pressure Sodium First introduced in 1965, Lucalox R high pres sure sodium lamps have proven themselves an excel lent source for a broad range of industrial r,nd i exterior lighting applications. They are the high...
van der Mark, M B
2015-01-01T23:59:59.000Z
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.
Splitting of Folded Strings in AdS_4*CP^3
Jun-Bao Wu
2012-08-04T23:59:59.000Z
We study classically splitting of two kinds of folded string solutions in AdS_4*CP^3. Conserved charges of the produced fragments are computed for each case. We find interesting patterns among these conserved charges.
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 ...
Young, Diana S. (Diana Santos), 1975-
2007-01-01T23:59:59.000Z
Virtuosic bowed string performance in many ways exemplifies the incredible potential of human physical performance and expression. Today, a great deal is known about the physics of the violin family and those factors ...
Three-Charge Black Holes and Quarter BPS States in Little String Theory
Giveon, Amit; Kutasov, David; Lee, Sungjay
2015-01-01T23:59:59.000Z
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.
Mechanism of the Cassie-Wenzel transition via the atomistic and continuum string methods
Alberto Giacomello; Simone Meloni; Marcus Mueller; Carlo Massimo Casciola
2014-11-17T23:59:59.000Z
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.
High-Energy String Scattering Amplitudes and Signless Stirling Number Identity
Jen-Chi Lee; Catherine H. Yan; Yi Yang
2012-07-18T23:59:59.000Z
We give a complete proof of a set of identities (7) proposed recently from calculation of high-energy string scattering amplitudes. These identities allow one to extract ratios among high-energy string scattering amplitudes in the fixed angle regime from high-energy amplitudes in the Regge regime. The proof is based on a signless Stirling number identity in combinatorial theory. The results are valid for arbitrary real values $L$ rather than only for $L=0,1$ proved previously. The identities for non-integer real value $L$ were recently shown to be realized in high-energy compactified string scattering amplitudes [He S., Lee J.C., Yang Y., arXiv:1012.3158]. The parameter $L$ is related to the mass level of an excited string state and can take non-integer values for Kaluza-Klein modes.
The Effective String of 3D Gauge Systems at the Deconfining Transition
M. Caselle; F. Gliozzi
1991-10-01T23:59:59.000Z
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.
Dilaton and axion bremsstrahlung from collisions of cosmic (super)strings
E. Yu. Melkumova; D. V. Gal'tsov; K. Salehi
2006-12-26T23:59:59.000Z
We calculate dilaton and axion radiation generated in the collision of two straight initially unexcited strings and give a rough cosmological estimate of dilaton and axion densities produced via this mechanism in the early universe.
Hastbacka, Mildred; Dieckmann, John; Bouza, Antonio
2013-03-30T23:59:59.000Z
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.
Craig, Katie
2014-07-03T23:59:59.000Z
1. Sweetness and Light. A novel. Judi lives in a nice, clean house with her seventeen year old stepson, who won’t talk to her in anything but monosyllables. His father, Nelson, and she are struggling to relate to each ...
Hacker, Randi; Tsutsui, William
2008-03-12T23:59:59.000Z
that you have only 17, no 16, no 15 seconds left to get to the other side before the light changes and the impatient American drivers put the pedal to the metal and it's road kill time. Talk about stress! In Tokyo, crossing the street is a leisurely...
Can a self-gravitating thin cosmic string obey the Nambu-Goto dynamics ?
B. Boisseau; C. Charmousis; B. Linet
1997-10-14T23:59:59.000Z
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.
Methods and systems for determining angular orientation of a drill string
Cobern, Martin E. (Cheshire, CT)
2010-03-23T23:59:59.000Z
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.
Semiclassical circular strings in AdS{sub 5} and 'long' gauge field strength operators
Park, I.Y.; Tirziu, A.; Tseytlin, A.A. [Department of Physics, Ohio State University, Columbus, Ohio 43210 (United States)
2005-06-15T23:59:59.000Z
We consider circular strings rotating with equal spins S{sub 1}=S{sub 2}=S in two orthogonal planes in AdS{sub 5} and suggest that they may be dual to long gauge-theory operators built out of self-dual components of gauge field strength. As was found in hep-th/0404187, the one-loop anomalous dimensions of the such gauge-theory operators are described by an antiferromagnetic XXX{sub 1} spin chain and scale linearly with length L>>1. We find that in the case of rigid rotating string both the classical energy E{sub 0} and the 1-loop string correction E{sub 1} depend linearly on the spin S (within the stability region of the solution). This supports the identification of the rigid rotating string with the gauge-theory operator corresponding to the maximal-spin (ferromagnetic) state of the XXX{sub 1} spin chain. The energy of more general rotating and pulsating strings also happens to scale linearly with both the spin and the oscillation number. Such solutions should be dual to other lower-spin states of the spin chain, with the antiferromagnetic ground state presumably corresponding to the string pulsating in two planes with no rotation.
TeV Scale Strings and Scattering Amplitudes at the LHC
Dean Carmi
2015-08-16T23:59:59.000Z
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.
Semiclassical Strings in Electric and Magnetic Fields Deformed $AdS_5 \\times S^5$ Spacetimes
Wung-Hong Huang
2006-01-06T23:59:59.000Z
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.
Cosmic strings in $f\\left(R,L_m\\right)$ gravity
Tiberiu Harko; Matthew J. Lake
2015-01-17T23:59:59.000Z
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.
Energy Production in the Formation of a Finite Thickness Cosmic String
I. Brevik; A. G. Frøseth
1999-09-29T23:59:59.000Z
The classical electromagnetic modes outside a long, straight, superconducting cosmic string are calculated, assuming the string to be surrounded by a superconducting cylindric surface of radius R. Thereafter, by use of a Bogoliubov-type argument, the electromagnetic energy W produced per unit length in the lowest two modes is calculated when the string is formed "suddenly". The essential new element in the present analysis as compared with prior work of Parker [Phys. Rev. Lett. {\\bf 59}, 1369 (1987)] and Brevik and Toverud [Phys. Rev. D {\\bf 51}, 691 (1995)], is that the radius {\\it a} of the string is assumed finite, thus necessitating Neumann functions to be included in the fundamental modes. We find that the theory is changed significantly: W is now strongly concentrated in the lowest mode $(m,s)=(0,1)$, whereas the proportionality $W \\propto (G\\mu /t)^2$ that is characteristic for zero-width strings is found in the next mode (1,1). Here G is the gravitational constant, $\\mu$ the string mass per unit length, and t the GUT time.
Superposed Coherent and Squeezed Light
Fesseha Kassahun
2012-01-18T23:59:59.000Z
We first calculate the mean photon number and quadrature variance of superposed coherent and squeezed light, following a procedure of analysis based on combining the Hamiltonians and using the usual definition for the quadrature variance of superposed light beams. This procedure of analysis leads to physically unjustifiable mean photon number of the coherent light and quadrature variance of the superposed light. We then determine both of these properties employing a procedure of analysis based on superposing the Q functions and applying a slightly modified definition for the quadrature variance of a pair of superposed light beams. We find the expected mean photon number of the coherent light and the quadrature variance of the superposed light. Moreover, the quadrature squeezing of the superposed output light turns out to be equal to that of the superposed cavity light.
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...
Types of Lighting in Commercial Buildings - Lighting Characteristics
U.S. Energy Information Administration (EIA) Indexed Site
Characteristics of Lighting Types Efficacy Efficacy is the amount of light produced per unit of energy consumed, expressed in lumens per watt (lmW). Lamps with a higher efficacy...
Quaglioni, S; Navratil, P; Roth, R
2009-12-15T23:59:59.000Z
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.
Pappas, Daniel S. (Los Alamos, NM)
1989-01-01T23:59:59.000Z
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.
Anil Duggal; Don Foust; Chris Heller; Bill Nealon; Larry Turner; Joe Shiang; Nick Baynes; Tim Butler; Nalin Patel
2004-02-29T23:59:59.000Z
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.