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Graviton J = 2
Citation: M. Tanabashi et al. (Particle Data Group), Phys. Rev. D 98, 030001 (2018) graviton J = 2 graviton MASS Van Dam and Veltman (VANDAM 70), Iwasaki (IWASAKI 70), and Za- kharov (ZAKHAROV 70) almost simultanously showed that “... there is a discrete difference between the theory with zero-mass and a theory with finite mass, no matter how small as compared to all external momenta.” The resolution of this ”vDVZ discontinuity” has to do with whether the linear approximation is valid. De Rham etal. (DE-RHAM 11) have shown that nonlinear effects not captured in their linear treatment can give rise to a screening mechanism, allowing for massive gravity theories. See also GOLDHABER 10 and DE-RHAM 17 and references therein. Experimental limits have been set based on a Yukawa potential or signal dispersion. h0 − − is the Hubble constant in units of 100 kms 1 Mpc 1. − The following conversions are useful: 1 eV = 1.783 × 10 33 g = 1.957 × −6 × −7 × 10 me ; λ¯C = (1.973 10 m) (1 eV/mg ). VALUE (eV) DOCUMENT ID TECN COMMENT − <6 × 10 32 1 CHOUDHURY 04 YUKA Weak gravitational lensing ••• We do not use the following data for averages, fits, limits, etc. ••• − <7 × 10 23 2 ABBOTT 17 DISP Combined dispersion limit from three BH mergers − <1.2 × 10 22 2 ABBOTT 16 DISP Combined dispersion limit from two BH mergers − <5 × 10 23 3 BRITO 13 Spinningblackholesbounds − <4 × 10 25 4 BASKARAN 08 Graviton phase velocity fluctua- − tions <6 × 10 32 5 GRUZINOV 05 YUKA Solar System observations − <9.0 × 10 34 6 GERSHTEIN 04 From Ω value assuming RTG − tot >6 × 10 34 7 DVALI 03 Horizon scales − <8 × 10 20 8,9 FINN 02 DISP Binary pulsar orbital period de- crease 9,10 DAMOUR 91 Binary pulsar PSR 1913+16 − <7 × 10 23 TALMADGE 88 YUKA Solar system planetary astrometric data − − < 2 × 10 29 h 1 GOLDHABER 74 Rich clusters − 0 <7 × 10 28 HARE 73 Galaxy <8 × 104 HARE 73 2γ decay 1 CHOUDHURY 04 concludes from a study of weak-lensing data that masses heavier than about the inverse of 100 Mpc seem to be ruled out if the gravitation field has the Yukawa form. -
Off-Shell Interactions for Closed-String Tachyons
Preprint typeset in JHEP style - PAPER VERSION hep-th/0403238 KIAS-P04017 SLAC-PUB-10384 SU-ITP-04-11 TIFR-04-04 Off-Shell Interactions for Closed-String Tachyons Atish Dabholkarb,c,d, Ashik Iqubald and Joris Raeymaekersa aSchool of Physics, Korea Institute for Advanced Study, 207-43, Cheongryangri-Dong, Dongdaemun-Gu, Seoul 130-722, Korea bStanford Linear Accelerator Center, Stanford University, Stanford, CA 94025, USA cInstitute for Theoretical Physics, Department of Physics, Stanford University, Stanford, CA 94305, USA dDepartment of Theoretical Physics, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India E-mail:[email protected], [email protected], [email protected] Abstract: Off-shell interactions for localized closed-string tachyons in C/ZN super- string backgrounds are analyzed and a conjecture for the effective height of the tachyon potential is elaborated. At large N, some of the relevant tachyons are nearly massless and their interactions can be deduced from the S-matrix. The cubic interactions be- tween these tachyons and the massless fields are computed in a closed form using orbifold CFT techniques. The cubic interaction between nearly-massless tachyons with different charges is shown to vanish and thus condensation of one tachyon does not source the others. It is shown that to leading order in N, the quartic contact in- teraction vanishes and the massless exchanges completely account for the four point scattering amplitude. This indicates that it is necessary to go beyond quartic inter- actions or to include other fields to test the conjecture for the height of the tachyon potential. Keywords: closed-string tachyons, orbifolds. -
Graviton J = 2
Citation: P.A. Zyla et al. (Particle Data Group), Prog. Theor. Exp. Phys. 2020, 083C01 (2020) graviton J = 2 graviton MASS Van Dam and Veltman (VANDAM 70), Iwasaki (IWASAKI 70), and Za- kharov (ZAKHAROV 70) almost simultanously showed that “... there is a discrete difference between the theory with zero-mass and a theory with finite mass, no matter how small as compared to all external momenta.” The resolution of this ”vDVZ discontinuity” has to do with whether the linear approximation is valid. De Rham etal. (DE-RHAM 11) have shown that nonlinear effects not captured in their linear treatment can give rise to a screening mechanism, allowing for massive gravity theories. See also GOLDHABER 10 and DE-RHAM 17 and references therein. Experimental limits have been set based on a Yukawa potential or signal dispersion. h0 − − is the Hubble constant in units of 100 kms 1 Mpc 1. − The following conversions are useful: 1 eV = 1.783 × 10 33 g = 1.957 × −6 × −7 × 10 me ; λ¯C = (1.973 10 m) (1 eV/mg ). VALUE (eV) DOCUMENT ID TECN COMMENT − <6 × 10 32 1 CHOUDHURY 04 YUKA Weak gravitational lensing • • • We do not use the following data for averages, fits, limits, etc. • • • − <6.8 × 10 23 BERNUS 19 YUKA Planetary ephemeris INPOP17b − <1.4 × 10 29 2 DESAI 18 YUKA Gal cluster Abell 1689 − <5 × 10 30 3 GUPTA 18 YUKA SPT-SZ − <3 × 10 30 3 GUPTA 18 YUKA Planck all-sky SZ − <1.3 × 10 29 3 GUPTA 18 YUKA redMaPPer SDSS-DR8 − <6 × 10 30 4 RANA 18 YUKA Weak lensing in massive clusters − <8 × 10 30 5 RANA 18 YUKA SZ effect in massive clusters − <7 × 10 23 6 ABBOTT -
Beyond the Cosmological Standard Model
Beyond the Cosmological Standard Model a;b; b; b; b; Austin Joyce, ∗ Bhuvnesh Jain, y Justin Khoury z and Mark Trodden x aEnrico Fermi Institute and Kavli Institute for Cosmological Physics University of Chicago, Chicago, IL 60637 bCenter for Particle Cosmology, Department of Physics and Astronomy University of Pennsylvania, Philadelphia, PA 19104 Abstract After a decade and a half of research motivated by the accelerating universe, theory and experi- ment have a reached a certain level of maturity. The development of theoretical models beyond Λ or smooth dark energy, often called modified gravity, has led to broader insights into a path forward, and a host of observational and experimental tests have been developed. In this review we present the current state of the field and describe a framework for anticipating developments in the next decade. We identify the guiding principles for rigorous and consistent modifications of the standard model, and discuss the prospects for empirical tests. We begin by reviewing recent attempts to consistently modify Einstein gravity in the in- frared, focusing on the notion that additional degrees of freedom introduced by the modification must \screen" themselves from local tests of gravity. We categorize screening mechanisms into three broad classes: mechanisms which become active in regions of high Newtonian potential, those in which first derivatives of the field become important, and those for which second deriva- tives of the field are important. Examples of the first class, such as f(R) gravity, employ the familiar chameleon or symmetron mechanisms, whereas examples of the last class are galileon and massive gravity theories, employing the Vainshtein mechanism. -
Exploring Cosmic Strings: Observable Effects and Cosmological Constraints
EXPLORING COSMIC STRINGS: OBSERVABLE EFFECTS AND COSMOLOGICAL CONSTRAINTS A dissertation submitted by Eray Sabancilar In partial fulfilment of the requirements for the degree of Doctor of Philosophy in Physics TUFTS UNIVERSITY May 2011 ADVISOR: Prof. Alexander Vilenkin To my parents Afife and Erdal, and to the memory of my grandmother Fadime ii Abstract Observation of cosmic (super)strings can serve as a useful hint to understand the fundamental theories of physics, such as grand unified theories (GUTs) and/or superstring theory. In this regard, I present new mechanisms to pro- duce particles from cosmic (super)strings, and discuss their cosmological and observational effects in this dissertation. The first chapter is devoted to a review of the standard cosmology, cosmic (super)strings and cosmic rays. The second chapter discusses the cosmological effects of moduli. Moduli are relatively light, weakly coupled scalar fields, predicted in supersymmetric particle theories including string theory. They can be emitted from cosmic (super)string loops in the early universe. Abundance of such moduli is con- strained by diffuse gamma ray background, dark matter, and primordial ele- ment abundances. These constraints put an upper bound on the string tension 28 as strong as Gµ . 10− for a wide range of modulus mass m. If the modulus coupling constant is stronger than gravitational strength, modulus radiation can be the dominant energy loss mechanism for the loops. Furthermore, mod- ulus lifetimes become shorter for stronger coupling. Hence, the constraints on string tension Gµ and modulus mass m are significantly relaxed for strongly coupled moduli predicted in superstring theory. Thermal production of these particles and their possible effects are also considered. -
Curriculum Vitae Markus Amadeus Luty
Curriculum Vitae Markus Amadeus Luty University of Maryland Department of Physics College Park, Maryland 20742 301-405-6018 e-mail: [email protected] Education Ph.D. in physics, University of Chicago, 1991 Honors B.S. in physics, B.S. in mathematics, University of Utah, 1987 Academic Honors Alfred P. Sloan Fellow (1997–1998) National Science Foundation Graduate Fellowship (1988–1991) Phi Beta Kappa, Phi Kappa Phi (1987) Kenneth Browning Memorial Scholarship (1986) National Merit Scholarship (1982–1986) Academic Positions 2001–present tenured associate professor, University of Maryland 1996–2001 assistant professor, University of Maryland 1994–1995 post-doctoral researcher, Massachusetts Institute of Technology 1991–1994 post-doctoral researcher, Lawrence Berkeley National Laboratory 1988–1991 graduate research assistant (with Y. Nambu), University of Chicago 1987–1988 graduate teaching assistant, University of Chicago 1985–1986 undergraduate teaching assistant, University of Utah 1 Recent Invited Conference/Workshop Talks • June 2003, SUSY 2003 (Tuscon) plenary talk: “Supersymmetry without Super- gravity.” • January 2003, PASCOS (Mumbai, India) plenary talk: “New ideas in super- symmetry breaking” • October 2002, Workshop on Frontiers Beyond the Standard Model (Mineapolis): “Supersymmetry without supergravity.” • August 2002, Santa Fe Workshop on Extra Dimensions and Beyond: “Super- symmetry without Supergravity.” • January 2002, ITP Brane World Workshop: “Anomaly Mediated Supersymme- try Breaking.” • April 2001, APS Division of Particles -
Generalised Velocity-Dependent One-Scale Model for Current-Carrying Strings
Generalised velocity-dependent one-scale model for current-carrying strings C. J. A. P. Martins,1, 2, ∗ Patrick Peter,3, 4, y I. Yu. Rybak,1, 2, z and E. P. S. Shellard4, x 1Centro de Astrofísica da Universidade do Porto, Rua das Estrelas, 4150-762 Porto, Portugal 2Instituto de Astrofísica e Ciências do Espaço, CAUP, Rua das Estrelas, 4150-762 Porto, Portugal 3 GR"CO – Institut d’Astrophysique de Paris, CNRS & Sorbonne Université, UMR 7095 98 bis boulevard Arago, 75014 Paris, France 4Centre for Theoretical Cosmology, Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA, United Kingdom (Dated: November 20, 2020) We develop an analytic model to quantitatively describe the evolution of superconducting cosmic string networks. Specifically, we extend the velocity-dependent one-scale (VOS) model to incorpo- rate arbitrary currents and charges on cosmic string worldsheets under two main assumptions, the validity of which we also discuss. We derive equations that describe the string network evolution in terms of four macroscopic parameters: the mean string separation (or alternatively the string correlation length) and the root mean square (RMS) velocity which are the cornerstones of the VOS model, together with parameters describing the averaged timelike and spacelike current contribu- tions. We show that our extended description reproduces the particular cases of wiggly and chiral cosmic strings, previously studied in the literature. This VOS model enables investigation of the evolution and possible observational signatures of superconducting cosmic string networks for more general equations of state, and these opportunities will be exploited in a companion paper. -
Classical and Quantum Consistency of the DGP Model
IFT-UAM/CSIC-04-13 CERN-PH-TH/2004-063 Classical and Quantum Consistency of the DGP Model Alberto Nicolis a and Riccardo Rattazzi b aInstituto de F´ısica Te´orica, C–XVI, UAM, 28049 Madrid, Spain bPhysics Department, Theory Division, CERN, CH–1211 Geneva 23, Switzerland Abstract We study the Dvali-Gabadadze-Porrati model by the method of the boundary effective action. The truncation of this action to the bending mode π consistently describes physics in a wide range of regimes both at the classical and at the quantum level. The Vainshtein effect, which restores agreement with precise tests of general relativity, follows straightforwardly. We give a simple and general proof of stability, i.e. absence of ghosts in the fluctuations, valid for most of the relevant cases, like for instance the spherical source in asymptotically flat space. However we confirm that around certain interesting self-accelerating cosmological solutions there is a ghost. We consider the issue of quantum corrections. Around flat space π becomes strongly coupled below a macroscopic length of 1000 km, thus impairing the predictivity of the model. Indeed the tower of higher dimensional operators which is expected by a generic UV completion of the model limits predictivity at even larger length scales. We outline a non-generic but consistent choice of counterterms for which this disaster does not happen and for which the model remains calculable and successful in all the astrophysical situations of interest. By this choice, the extrinsic curvature Kµν acts roughly like a dilaton field controlling the strength of the interaction and the cut-off scale at each space-time point. -
Cosmic Strings and Primordial Black Holes
Journal of Cosmology and Astroparticle Physics Cosmic strings and primordial black holes Recent citations - Extended thermodynamics of self- gravitating skyrmions To cite this article: Alexander Vilenkin et al JCAP11(2018)008 Daniel Flores-Alfonso and Hernando Quevedo View the article online for updates and enhancements. This content was downloaded from IP address 130.64.25.60 on 13/07/2019 at 23:53 ournal of Cosmology and Astroparticle Physics JAn IOP and SISSA journal Cosmic strings and primordial black holes JCAP11(2018)008 Alexander Vilenkin,a Yuri Levinb and Andrei Gruzinovc aDepartment of Physics and Astronomy, Tufts University, 574 Boston Avenue, Medford, MA 02155, U.S.A. bDepartment of Physics, Columbia University, 538 West 120th street, New York, NY 10027, U.S.A. cDepartment of Physics, New York University, 726 Broadway, New York, NY 10003, U.S.A. E-mail: [email protected], [email protected], [email protected] Received September 10, 2018 Accepted October 10, 2018 Published November 7, 2018 Abstract. Cosmic strings and primordial black holes (PBHs) commonly and naturally form in many scenarios describing the early universe. Here we show that if both cosmic strings and PBHs are present, their interaction leads to a range of interesting consequences. At the time of their formation, the PBHs get attached to the strings and influence their evolution, leading to the formation of black-hole-string networks and commonly to the suppression of loop production in a range of redshifts. Subsequently, reconnections within the network give rise to small nets made of several black holes and connecting strings. -
Cosmological Implications of Modified Gravity: Spherical Collapse and Higher Order Correlations
University of Pennsylvania ScholarlyCommons Publicly Accessible Penn Dissertations Fall 2009 COSMOLOGICAL IMPLICATIONS OF MODIFIED GRAVITY: SPHERICAL COLLAPSE AND HIGHER ORDER CORRELATIONS Alexander Borisov University of Pennsylvania, [email protected] Follow this and additional works at: https://repository.upenn.edu/edissertations Part of the Cosmology, Relativity, and Gravity Commons Recommended Citation Borisov, Alexander, "COSMOLOGICAL IMPLICATIONS OF MODIFIED GRAVITY: SPHERICAL COLLAPSE AND HIGHER ORDER CORRELATIONS" (2009). Publicly Accessible Penn Dissertations. 47. https://repository.upenn.edu/edissertations/47 This paper is posted at ScholarlyCommons. https://repository.upenn.edu/edissertations/47 For more information, please contact [email protected]. COSMOLOGICAL IMPLICATIONS OF MODIFIED GRAVITY: SPHERICAL COLLAPSE AND HIGHER ORDER CORRELATIONS Abstract In the Standard Model of Cosmology the nature of the Dark Energy has become one of the most significant and conceptual challenges ot be resolved. One of the possible approaches to solving it is to introduce modifications ot General Relativity, that include Chameleon effects, which allow for a change in the strength of gravity based on the environment. This can provide for a consistent explanation of both large-scale observations and Solar system experiments. In the task to distinguish them from the LCDM model of gravity, or any other competing explanation, we need to study the consequences of these modifications for the growth of perturbations. In this thesis a recently developed Chameleon f(R) modification ot gravity is explored. We study its consequences for the distribution of matter on large scale using the Bispectrum. Using 1D simulations we examine the formation of galaxy and cluster halos and its observational effects. Finally we present an investigation of a method for studying gravitational lensing. -
Arxiv:Hep-Th/0207119V4 8 Oct 2002
Rolling Tachyon in Brane World Cosmology from Superstring Field Theory Gary Shiu1, S.-H. Henry Tye2, and Ira Wasserman3 1 Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104 2 Laboratory for Elementary Particle Physics, Cornell University, Ithaca, NY 14853 3 Center for Radiophysics and Space Research, Cornell University, Ithaca, NY 14853 (November 12, 2018) The pressureless tachyonic matter recently found in superstring field theory has an over-abundance problem in cosmology. We argue that this problem is naturally solved in the brane inflationary scenario if almost all of the tachyon energy is drained (via coupling to the inflaton and matter fields) to heating the Universe, while the rest of the tachyon energy goes to a network of cosmic strings (lower-dimensional BPS D-branes) produced during the tachyon rolling at the end of inflation. PACS numbers: 11.25.-q, 11.27.+d, 98.80.Cq In superstring theory, starting with a non-BPS brane still give detectable signatures in the cosmic microwave or a brane-anti-brane pair, a tachyon is always present. background and the gravitational wave spectral density This tachyon rolls down its potential and tachyon matter [9,10]. To summarize, the over-abundance of the tachyon appears as energy density without pressure, as pointed matter density problem can be solved rather naturally out by Sen [1]. In the cosmological context [2], it is by draining the tachyon potential energy to (re-)heating easy to estimate that the pressureless tachyonic matter and to the cosmic string production. Below, we discuss density is generically many orders of magnitude too big these two mechanisms. -
Quantum Gravity and Gravitational-Wave Astronomy
4 July 2019 Quantum gravity and gravitational-wave astronomy Gianluca Calcagni,a Sachiko Kuroyanagi,b;c Sylvain Marsat,d Mairi Sakellariadou,e Nicola Tamanini,f Gianmassimo Tasinatog aInstituto de Estructura de la Materia, CSIC, Serrano 121, 28006 Madrid, Spain bDepartment of Physics, Nagoya University, Chikusa, Nagoya 464-8602, Japan cInstituto de F´ısicaTe´oricaUAM-CSIC, Universidad Auton´omade Madrid, Cantoblanco, 28049 Madrid, Spain dAPC, AstroParticule et Cosmologie, Universit´eParis Diderot, CNRS/IN2P3, CEA/Irfu, Observatoire de Paris, Sorbonne Paris Cit´e,10, rue Alice Domon et L´eonieDuquet 75205 PARIS Cedex 13, France eTheoretical Particle Physics and Cosmology Group, Physics Department, King's College London, University of London, Strand, London WC2R 2LS, United Kingdom f Max-Planck-Institut f¨urGravitationsphysik, Albert-Einstein-Institut, Am M¨uhlenberg 1, 14476 Potsdam-Golm, Germany gDepartment of Physics, Swansea University, Swansea, SA2 8PP, UK E-mail: [email protected], [email protected], [email protected], [email protected], [email protected], g.tasinato2208gmail.com Abstract. We investigate possible signatures of quantum gravity which could be tested with current and future gravitational-wave (GW) observations. In particular, we analyze how quantum gravity can influence the GW luminosity distance, the time dependence of the effective Planck mass and the instrumental strain noise of interferometers. Using both model-dependent and model-independent formulæ, we show that these quantities can encode a non-perturbative effect typical of all quantum-gravity theories, namely the way the dimen- sion of spacetime changes with the probed scale. Effects associated with such dimensional arXiv:1907.02489v1 [gr-qc] 4 Jul 2019 flow might be tested with GW observations and constrained significantly in theories with a microscopically discrete spacetime geometry, more strongly than from propagation-speed constraints.