Planar Yang-Mills 101 Nicholas R. Wright Natchitoches
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Universal Thermodynamics in the Context of Dynamical Black Hole
universe Article Universal Thermodynamics in the Context of Dynamical Black Hole Sudipto Bhattacharjee and Subenoy Chakraborty * Department of Mathematics, Jadavpur University, Kolkata 700032, West Bengal, India; [email protected] * Correspondence: [email protected] Received: 27 April 2018; Accepted: 22 June 2018; Published: 1 July 2018 Abstract: The present work is a brief review of the development of dynamical black holes from the geometric point view. Furthermore, in this context, universal thermodynamics in the FLRW model has been analyzed using the notion of the Kodama vector. Finally, some general conclusions have been drawn. Keywords: dynamical black hole; trapped surfaces; universal thermodynamics; unified first law 1. Introduction A black hole is a region of space-time from which all future directed null geodesics fail to reach the future null infinity I+. More specifically, the black hole region B of the space-time manifold M is the set of all events P that do not belong to the causal past of future null infinity, i.e., B = M − J−(I+). (1) Here, J−(I+) denotes the causal past of I+, i.e., it is the set of all points that causally precede I+. The boundary of the black hole region is termed as the event horizon (H), H = ¶B = ¶(J−(I+)). (2) A cross-section of the horizon is a 2D surface H(S) obtained by intersecting the event horizon with a space-like hypersurface S. As event the horizon is a causal boundary, it must be a null hypersurface generated by null geodesics that have no future end points. In the black hole region, there are trapped surfaces that are closed 2-surfaces (S) such that both ingoing and outgoing congruences of null geodesics are orthogonal to S, and the expansion scalar is negative everywhere on S. -
Dynamics of the Four Kinds of Trapping Horizons & Existence of Hawking
Dynamics of the four kinds of Trapping Horizons & Existence of Hawking Radiation Alexis Helou1 AstroParticule et Cosmologie, Universit´eParis Diderot, CNRS, CEA, Observatoire de Paris, Sorbonne Paris Cit´e Bˆatiment Condorcet, 10, rue Alice Domon et L´eonieDuquet, F-75205 Paris Cedex 13, France Abstract We work with the notion of apparent/trapping horizons for spherically symmetric, dynamical spacetimes: these are quasi-locally defined, simply based on the behaviour of congruence of light rays. We show that the sign of the dynamical Hayward-Kodama surface gravity is dictated by the in- ner/outer nature of the horizon. Using the tunneling method to compute Hawking Radiation, this surface gravity is then linked to a notion of temper- ature, up to a sign that is dictated by the future/past nature of the horizon. Therefore two sign effects are conspiring to give a positive temperature for the black hole case and the expanding cosmology, whereas the same quantity is negative for white holes and contracting cosmologies. This is consistent with the fact that, in the latter cases, the horizon does not act as a separating membrane, and Hawking emission should not occur. arXiv:1505.07371v1 [gr-qc] 27 May 2015 [email protected] Contents 1 Introduction 1 2 Foreword 2 3 Past Horizons: Retarded Eddington-Finkelstein metric 4 4 Future Horizons: Advanced Eddington-Finkelstein metric 10 5 Hawking Radiation from Tunneling 12 6 The four kinds of apparent/trapping horizons, and feasibility of Hawking radiation 14 6.1 Future-outer trapping horizon: black holes . 15 6.2 Past-inner trapping horizon: expanding cosmology . -
Stephen Hawking: 'There Are No Black Holes' Notion of an 'Event Horizon', from Which Nothing Can Escape, Is Incompatible with Quantum Theory, Physicist Claims
NATURE | NEWS Stephen Hawking: 'There are no black holes' Notion of an 'event horizon', from which nothing can escape, is incompatible with quantum theory, physicist claims. Zeeya Merali 24 January 2014 Artist's impression VICTOR HABBICK VISIONS/SPL/Getty The defining characteristic of a black hole may have to give, if the two pillars of modern physics — general relativity and quantum theory — are both correct. Most physicists foolhardy enough to write a paper claiming that “there are no black holes” — at least not in the sense we usually imagine — would probably be dismissed as cranks. But when the call to redefine these cosmic crunchers comes from Stephen Hawking, it’s worth taking notice. In a paper posted online, the physicist, based at the University of Cambridge, UK, and one of the creators of modern black-hole theory, does away with the notion of an event horizon, the invisible boundary thought to shroud every black hole, beyond which nothing, not even light, can escape. In its stead, Hawking’s radical proposal is a much more benign “apparent horizon”, “There is no escape from which only temporarily holds matter and energy prisoner before eventually a black hole in classical releasing them, albeit in a more garbled form. theory, but quantum theory enables energy “There is no escape from a black hole in classical theory,” Hawking told Nature. Peter van den Berg/Photoshot and information to Quantum theory, however, “enables energy and information to escape from a escape.” black hole”. A full explanation of the process, the physicist admits, would require a theory that successfully merges gravity with the other fundamental forces of nature. -
The Negative Energy in Generalized Vaidya Spacetime
universe Communication The Negative Energy in Generalized Vaidya Spacetime Vitalii Vertogradov 1,2 1 Department of the Theoretical Physics and Astronomy, Herzen State Pedagogical University, 191186 St. Petersburg, Russia; [email protected] 2 The SAO RAS, Pulkovskoe Shosse 65, 196140 St. Petersburg, Russia Received: 17 August 2020; Accepted: 17 September 2020; Published: 22 September 2020 Abstract: In this paper we consider the negative energy problem in generalized Vaidya spacetime. We consider several models where we have the naked singularity as a result of the gravitational collapse. In these models we investigate the geodesics for particles with negative energy when the II type of the matter field satisfies the equation of the state P = ar (a 2 [0 , 1]). Keywords: generalized Vaidya spacetime; naked singularity; black hole; negative energy 1. Introduction In 1969 R. Penrose theoretically predicted the effect of the negative energy formation in the Kerr metric during the process of the decay or the collision. Furthermore, the nature of the geodesics for particles with negative energy was investigated [1,2]. It was shown that in the ergosphere of a rotating black hole closed orbits for such particles are absent. This geodesics must appear from the region inside the gravitational radius. Moreover, there was research devoted to the particles with negative energy in Schwarzschild spacetime which was conducted by A. A. Grib and Yu. V. Pavlov [3]. They showed that the particles with negative energy can exist only in the region inside of the event horizon. However, the Schwarzschild black hole is the eternal one and we must consider the gravitational collapse to speak about the past of the geodesics for particles with negative energy. -
Radiative Corrections in Curved Spacetime and Physical Implications to the Power Spectrum and Trispectrum for Different Inflationary Models
Radiative Corrections in Curved Spacetime and Physical Implications to the Power Spectrum and Trispectrum for different Inflationary Models Dissertation zur Erlangung des mathematisch-naturwissenschaftlichen Doktorgrades Doctor rerum naturalium der Georg-August-Universit¨atG¨ottingen Im Promotionsprogramm PROPHYS der Georg-August University School of Science (GAUSS) vorgelegt von Simone Dresti aus Locarno G¨ottingen,2018 Betreuungsausschuss: Prof. Dr. Laura Covi, Institut f¨urTheoretische Physik, Universit¨atG¨ottingen Prof. Dr. Karl-Henning Rehren, Institut f¨urTheoretische Physik, Universit¨atG¨ottingen Prof. Dr. Dorothea Bahns, Mathematisches Institut, Universit¨atG¨ottingen Miglieder der Prufungskommission:¨ Referentin: Prof. Dr. Laura Covi, Institut f¨urTheoretische Physik, Universit¨atG¨ottingen Korreferentin: Prof. Dr. Dorothea Bahns, Mathematisches Institut, Universit¨atG¨ottingen Weitere Mitglieder der Prufungskommission:¨ Prof. Dr. Karl-Henning Rehren, Institut f¨urTheoretische Physik, Universit¨atG¨ottingen Prof. Dr. Stefan Kehrein, Institut f¨urTheoretische Physik, Universit¨atG¨ottingen Prof. Dr. Jens Niemeyer, Institut f¨urAstrophysik, Universit¨atG¨ottingen Prof. Dr. Ariane Frey, II. Physikalisches Institut, Universit¨atG¨ottingen Tag der mundlichen¨ Prufung:¨ Mittwoch, 23. Mai 2018 Ai miei nonni Marina, Palmira e Pierino iv ABSTRACT In a quantum field theory with a time-dependent background, as in an expanding uni- verse, the time-translational symmetry is broken. We therefore expect loop corrections to cosmological observables to be time-dependent after renormalization for interacting fields. In this thesis we compute and discuss such radiative corrections to the primordial spectrum and higher order spectra in simple inflationary models. We investigate both massless and massive virtual fields, and we disentangle the time dependence caused by the background and by the initial state that is set to the Bunch-Davies vacuum at the beginning of inflation. -
Scalar Quantum Electrodynamics
A complex system that works is invariably found to have evolved from a simple system that works. John Gall 17 Scalar Quantum Electrodynamics In nature, there exist scalar particles which are charged and are therefore coupled to the electromagnetic field. In three spatial dimensions, an important nonrelativistic example is provided by superconductors. The phenomenon of zero resistance at low temperature can be explained by the formation of so-called Cooper pairs of electrons of opposite momentum and spin. These behave like bosons of spin zero and charge q =2e, which are held together in some metals by the electron-phonon interaction. Many important predictions of experimental data can be derived from the Ginzburg- Landau theory of superconductivity [1]. The relativistic generalization of this theory to four spacetime dimensions is of great importance in elementary particle physics. In that form it is known as scalar quantum electrodynamics (scalar QED). 17.1 Action and Generating Functional The Ginzburg-Landau theory is a three-dimensional euclidean quantum field theory containing a complex scalar field ϕ(x)= ϕ1(x)+ iϕ2(x) (17.1) coupled to a magnetic vector potential A. The scalar field describes bound states of pairs of electrons, which arise in a superconductor at low temperatures due to an attraction coming from elastic forces. The detailed mechanism will not be of interest here; we only note that the pairs are bound in an s-wave and a spin singlet state of charge q =2e. Ignoring for a moment the magnetic interactions, the ensemble of these bound states may be described, in the neighborhood of the superconductive 4 transition temperature Tc, by a complex scalar field theory of the ϕ -type, by a euclidean action 2 3 1 m g 2 E = d x ∇ϕ∗∇ϕ + ϕ∗ϕ + (ϕ∗ϕ) . -
Asymptotically Flat, Spherical, Self-Interacting Scalar, Dirac and Proca Stars
S S symmetry Article Asymptotically Flat, Spherical, Self-Interacting Scalar, Dirac and Proca Stars Carlos A. R. Herdeiro and Eugen Radu * Departamento de Matemática da Universidade de Aveiro and Centre for Research and Development in Mathematics and Applications (CIDMA), Campus de Santiago, 3810-183 Aveiro, Portugal; [email protected] * Correspondence: [email protected] Received: 14 November 2020; Accepted: 1 December 2020; Published: 8 December 2020 Abstract: We present a comparative analysis of the self-gravitating solitons that arise in the Einstein–Klein–Gordon, Einstein–Dirac, and Einstein–Proca models, for the particular case of static, spherically symmetric spacetimes. Differently from the previous study by Herdeiro, Pombo and Radu in 2017, the matter fields possess suitable self-interacting terms in the Lagrangians, which allow for the existence of Q-ball-type solutions for these models in the flat spacetime limit. In spite of this important difference, our analysis shows that the high degree of universality that was observed by Herdeiro, Pombo and Radu remains, and various spin-independent common patterns are observed. Keywords: solitons; boson stars; Dirac stars 1. Introduction and Motivation 1.1. General Remarks The (modern) idea of solitons, as extended particle-like configurations, can be traced back (at least) to Lord Kelvin, around one and half centuries ago, who proposed that atoms are made of vortex knots [1]. However, the first explicit example of solitons in a relativistic field theory was found by Skyrme [2,3], (almost) one hundred years later. The latter, dubbed Skyrmions, exist in a model with four (real) scalars that are subject to a constraint. -
A Solvable Tensor Field Theory Arxiv:1903.02907V2 [Math-Ph]
A Solvable Tensor Field Theory R. Pascalie∗ Universit´ede Bordeaux, LaBRI, CNRS UMR 5800, Talence, France, EU Mathematisches Institut der Westf¨alischen Wilhelms-Universit¨at,M¨unster,Germany, EU August 3, 2020 Abstract We solve the closed Schwinger-Dyson equation for the 2-point function of a tensor field theory with a quartic melonic interaction, in terms of Lambert's W-function, using a perturbative expansion and Lagrange-B¨urmannresummation. Higher-point functions are then obtained recursively. 1 Introduction Tensor models have regained a considerable interest since the discovery of their large N limit (see [1], [2], [3] or the book [4]). Recently, tensor models have been related in [5] and [6], to the Sachdev-Ye-Kitaev model [7], [8], [9], [10], which is a promising toy-model for understanding black holes through holography (see also [11], [12], the lectures [13] and the review [14]). In this paper we study a specific type of tensor field theory (TFT) 1. More precisely, we consider a U(N)-invariant tensor models whose kinetic part is modified to include a Laplacian- like operator (this operator is a discrete Laplacian in the Fourier transformed space of the tensor index space). This type of tensor model has originally been used to implement renormalization techniques for tensor models (see [16], the review [17] or the thesis [18] and references within) and has also been studied as an SYK-like TFT [19]. Recently, the functional Renormalization Group (FRG) as been used in [20] to investigate the existence of a universal continuum limit in tensor models, see also the review [21]. -
On Dark Energy Models of Single Scalar Field
Home Search Collections Journals About Contact us My IOPscience On dark energy models of single scalar field This content has been downloaded from IOPscience. Please scroll down to see the full text. JCAP04(2012)003 (http://iopscience.iop.org/1475-7516/2012/04/003) View the table of contents for this issue, or go to the journal homepage for more Download details: IP Address: 140.112.101.4 This content was downloaded on 06/11/2014 at 07:57 Please note that terms and conditions apply. ournal of Cosmology and Astroparticle Physics JAn IOP and SISSA journal On dark energy models of single scalar field JCAP04(2012)003 Mingzhe Li,a,f Taotao Qiu,b,c Yifu Caid and Xinmin Zhange aDepartment of Physics, Nanjing University, Nanjing 210093, P.R. China bDepartment of Physics and Center for Theoretical Sciences, National Taiwan University, Taipei 10617, Taiwan cLeung Center for Cosmology and Particle Astrophysics, National Taiwan University, Taipei 106, Taiwan dDepartment of Physics, Arizona State University, Tempe, AZ 85287, U.S.A. eInstitute of High Energy Physics, Chinese Academy of Sciences, P.O. Box 918-4, Beijing 100049, P.R. China f Joint Center for Particle, Nuclear Physics and Cosmology, Nanjing University — Purple Mountain Observatory, Nanjing 210093, P.R. China E-mail: [email protected], [email protected], [email protected], [email protected] Received January 2, 2012 Accepted March 7, 2012 Published April 2, 2012 Abstract. In this paper we revisit the dynamical dark energy model building based on single scalar field involving higher derivative terms. By imposing a degenerate condition on the higher derivatives in curved spacetime, one can select the models which are free from the ghost mode and the equation of state is able to cross the cosmological constant boundary smoothly, dynamically violate the null energy condition. -
Cosmología De Tiempo Tardío Para Un Campo Escalar Con
Cosmolog´ıa de Tiempo Tard´ıo para un Campo Escalar con Acoplamientos Cinetico´ y de Gauss-Bonnet Edwin Loaiza Acuna˜ Tesis doctoral presentada como requisito parcial para optar al t´ıtulo de Doctor en Ciencias - F´ısica Director: Luis Norberto Granda Velasquez´ Universidad del Valle Facultad de Ciencias Naturales y Exactas Programa Academico´ de postgrado en F´ısica Julio 2016 Abstract In this thesis we study late-time cosmological solutions for a scalar field model with kinetic coupling to curvature and the scalar field coupled to the Gauss-Bonnet inva- riant, in order to explain the late-time accelerated expansion of the universe. Initially, exact cosmological solutions that show the phases of decelerated expansion, accelera- ted expansion and transition to the phantom phase have been found. These phases are necessary for the satisfactory explanation of the early inflation, and the current acce- lerated (super accelerated) expansion of the universe. These solutions have been found by imposing appropriate restrictions on the Gauss-Bonnet and kinetic couplings, ba- sed on the asimptotic limits of the Friedmann equations. Solutions with Big Rip and without Big Rip singularities have been studied. An especific choice of the Gauss- Bonnet coupling, where the squared of the Hubble parameter is proportional to the kinetic term, allows the reconstruction of the model for an appropriate cosmological evolution. The new found solution can describe the three cosmological phases that go from the power-law expansion, that describes a matter dominated universe, to the scalar field dominated phantom phase. For this solution and according to the values of the equation of state parameter during di↵erent epochs, the parameters of the solution can be adjusted in order to obtain di↵erent scenarios with and without Big Rip singularities. -
Arxiv:2003.01034V1 [Hep-Th] 2 Mar 2020 Im Oe.Frta Esntelna Oe a Etogta Ge a Large As the Thought in Be Solved Be Can Can Model Models Linear These the One
Inhomogeneous states in two dimensional linear sigma model at large N A. Pikalov1,2∗ 1Moscow Institute of Physics and Technology, Dolgoprudny 141700, Russia 2Institute for Theoretical and Experimental Physics, Moscow, Russia (Dated: March 3, 2020) In this note we consider inhomogeneous solutions of two-dimensional linear sigma model in the large N limit. These solutions are similar to the ones found recently in two-dimensional CP N sigma model. The solution exists only for some range of coupling constant. We calculate energy of the solutions as function of parameters of the model and show that at some value of the coupling constant it changes sign signaling a possible phase transition. The case of the nonlinear model at finite temperature is also discussed. The free energy of the inhomogeneous solution is shown to change sign at some critical temperature. I. INTRODUCTION Two-dimensional linear sigma model is a theory of N real scalar fields and quartic O(N) symmetric interaction. The model has two dimensionful parameters: mass of the particles and coupling constant. In the limit of infinite coupling one can obtain the nonlinear O(N) arXiv:2003.01034v1 [hep-th] 2 Mar 2020 sigma model. For that reason the linear model can be thought as a generalization of the nonlinear one. These models can be solved in the large N limit, see [1] for a review. In turn O(N) sigma model is quite similar to the CP N sigma model. Recently the large N CP N sigma model was considered on a finite interval with various boundary conditions [2–8] and on circle [9–12]. -
Physics 215C: Particles and Fields Spring 2019
Physics 215C: Particles and Fields Spring 2019 Lecturer: McGreevy These lecture notes live here. Please email corrections to mcgreevy at physics dot ucsd dot edu. Last updated: 2021/04/20, 14:28:40 1 Contents 0.1 Introductory remarks for the third quarter................4 0.2 Sources and acknowledgement.......................7 0.3 Conventions.................................8 1 Anomalies9 2 Effective field theory 20 2.1 A parable on integrating out degrees of freedom............. 20 2.2 Introduction to effective field theory.................... 25 2.3 The color of the sky............................. 30 2.4 Fermi theory of Weak Interactions..................... 32 2.5 Loops in EFT................................ 33 2.6 The Standard Model as an EFT...................... 39 2.7 Superconductors.............................. 42 2.8 Effective field theory of Fermi surfaces.................. 47 3 Geometric and topological terms in field theory actions 58 3.1 Coherent state path integrals for bosons................. 58 3.2 Coherent state path integral for fermions................. 66 3.3 Path integrals for spin systems....................... 73 3.4 Topological terms from integrating out fermions............. 86 3.5 Pions..................................... 89 4 Field theory of spin systems 99 4.1 Transverse-Field Ising Model........................ 99 4.2 Ferromagnets and antiferromagnets..................... 131 4.3 The beta function for 2d non-linear sigma models............ 136 4.4 CP1 representation and large-N ...................... 138 5 Duality 148 5.1 XY transition from superfluid to Mott insulator, and T-duality..... 148 6 Conformal field theory 158 6.1 The stress tensor and conformal invariance (abstract CFT)....... 160 6.2 Radial quantization............................. 166 6.3 Back to general dimensions......................... 172 7 Duality, part 2 179 7.1 (2+1)-d XY is dual to (2+1)d electrodynamics.............