DOCSLIB.ORG

Callan-Giddings-Harvey-Strominger Vacuum in Loop Quantum Gravity and Singularity Resolution

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Callan-Giddings-Harvey-Strominger Vacuum in Loop Quantum Gravity and Singularity Resolution Callan-Giddings-Harvey-Strominger vacuum in loop quantum gravity and singularity resolution Alejandro Corichi,1, 2, ∗ Javier Olmedo,3, 4, y and Saeed Rastgoo5, 1, z 1Centro de Ciencias Matemticás, Universidad Nacional Autónoma de México, Campus Morelia, Apartado Postal 61-3, Morelia, Michoacán 58090, Mexico 2Center for Fundamental Theory, Institute for Gravitation and the Cosmos, Pennsylvania State University, University Park, PA 16802, USA 3Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803-4001, USA 4Instituto de Física, Facultad de Ciencias, Iguá 4225, Montevideo, Uruguay 5Departamento de Física, Universidad Autónoma Metropolitana - Iztapalapa San Rafael Atlixco 186, México D.F. 09340, México (Dated: May 9, 2018) We study here a complete quantization of a Callan-Giddings-Harvey-Strominger (CGHS) vacuum model following loop quantum gravity techniques. Concretely, we adopt a formu- lation of the model in terms of a set of new variables that resemble the ones commonly employed in spherically symmetric loop quantum gravity. The classical theory consists of two pairs of canonical variables plus a scalar and diffeomorphism (first class) constraints. We consider a suitable redefinition of the Hamiltonian constraint such that the new constraint algebra (with structure constants) is well adapted to the Dirac quantization approach. For it, we adopt a polymeric representation for both the geometry and the dilaton field. On the one hand, we find a suitable invariant domain of the scalar constraint operator, and we construct explicitly its solution space. There, the eigenvalues of the dilaton and the metric operators cannot vanish locally, allowing us to conclude that singular geometries are ruled out in the quantum theory. On the other hand, the physical Hilbert space is constructed out of them, after group averaging the previous states with the diffeomorphism constraint. In turn, we identify the standard observable corresponding to the mass of the black hole at the boundary, in agreement with the classical theory. We also construct an additional observable on the bulk associated with the square of the dilaton field, with no direct classical analog. I. INTRODUCTION the old theory broke down. Owing to the fact that working with the full Since the early days of the search for a quan- theory is, so far, intractable, it has become stan- tum theory of gravity, there has always been the dard practice to work with lower dimensional expectation that one of the results that such a models or symmetry reduced ones, since gener- complete theory will yield, would be the resolu- ally this allows more control over the analysis. arXiv:1608.06246v2 [gr-qc] 29 Oct 2016 tion of the spacetime singularities. The first and One of these systems is the well known Callan- simplest reason for this argument is that singu- Giddings-Harvey-Strominger (CGHS) model [1]. larities are in a way, places where general relativ- It is a two dimensional dilatonic model that, in ity and the continuous description of spacetime spite of being simpler and classically solvable, break down. As in other instances in the history has nontrivial and interesting properties such as of physics, this is the regime where one should a black hole solution, Hawking radiation, etc. It look for a new theory. Obviously, any of those has been proven to be a very convenient model new theories should be able to produce the previ- for testing some of the quantum gravity ideas ously known results of the old theory and also be in the past, and it has been subject to many able to describe the physics in the regime where analyses over the past 20 years [2, 3] which has shed some light on the properties of the quantum ∗ [email protected] theory of the full 4D theory. In particular, addi- y [email protected] tional studies of the classical [4] and the semiclas- z [email protected] sical [5] regimes of this model, as well as several 2 studies of its quantization [6–8], have yielded a the geometry, together with a canonical trans- deeper understanding of some of the interesting formation in order to achieve a description as physical phenomena in this toy model that can similar as possible to the one of Ref. [22] in 3+1 be expected to be valid also in more realistic sit- at the kinematical level. Then, after consider- uations, like 4D black holes. However, there are ing some second class conditions and solving the still several questions that remain unanswered, Gauss constraint classically, one ends with a to- one of them being the way in which a quantum tally first class system with a Hamiltonian and a theory of gravity resolves the classical singular- diffeomorphism constraint. Furthermore, based ity. on a proposal in Refs. [24, 25], a redefinition In this article, we study the quantization of of the scalar constraint is made, such that this the CGHS model in a new perspective, namely constraint admits the standard algebra with the within the framework of loop quantum gravity diffeomorphism constraint, while having a van- (LQG) [9–11]. This programme pursues a back- ishing brackets with itself. In this situation, we ground independent non-perturbative quantiza- can follow similar arguments to those in [20] to tion of gravity. It provides a robust kinemati- achieve a complete quantization of the CGHS cal framework [12], while the dynamics has not model, showing that the quantum theory pro- been completely implemented. The application vides a description where the singularity is re- of LQG quantization techniques to simpler mod- solved in a certain way. Additionally some new els, known as loop quantum cosmology (LQC), observable emerge in the quantum regime, which has dealt with the question of the resolution of have no classical analogue. the singularity at different levels in models sim- ilar to the one under study —see for instance Refs. [5, 13–20] among others—. In particular, we will pay special attention to Refs. [19, 20], where a complete quantization of a 3+1 vacuum spherically symmetric spacetime has been pro- vided, and the singularity of the model is re- The structure of this paper is as follows: in solved in a very specific manner. The concrete section II, we present a very brief review of the mechanisms are based on the requirement of self- CGHS model to show that it contains a black adjointness of some observables of the model, hole solution with a singularity. Section III is and on the fact that, at the early stages of the dedicated to recall how one can derive polar- quantization, there is a natural restriction to a type variables for the Hamiltonian formulation of subspace of the kinematical Hilbert space whose the CGHS and 3+1 spherically symmetric mod- states correspond to eigenstates of the triad oper- els from a generic 2D dilatonic action, and thus ators with non-vanishing eigenvalues, from which showing the underlying similarity between the the evolution is completely determined. two models in these variables. In section IV, The purpose of the present work is to put for- we illustrate a way to turn the Dirac algebra of ward a quantization of the CGHS model, by ex- the constraint in the CGHS into a Lie algebra, tending the methods of [20] to the case at hand. and thus preparing it for the Dirac quantization. A study of the dilatonic systems in the lines of Section V is about quantization: we first intro- Poisson sigma models in LQG was already car- duce the kinematical Hilbert space of the theory ried out in Ref. [21]. The feasibility of the in V A, we then represent the Hamiltonian con- project we are considering rests on a classical re- straint on this space in V B, and in subsection sult that allows to cast the CGHS model in the V C, we argue about the resolution of the singu- so-called polar-type variables [22], similar to the larity in CGHS. Then, we put forward a discus- ones used for the 3+1 spherically symmetric case. sion about the properties of the solutions to the These variables were introduced in [23, 24] and Hamiltonian constraint in section V D. Finally were further generalized in [25]. Concretely, one we note in section V E that the same observables introduces a triadic description of the model for first derived in [19] can also be introduced here. 3 II. BRIEF REVIEW OF THE CGHS to the CGHS model is writing the latter in polar- MODEL type variables [22]. This has been mainly done in [23–25]. Here, we give a brief review of this for- The CGHS model [1] is a 2D dilatonic model. mulation and its key similarities and differences It has a black hole solution, Hawking radiation, to the 3+1 spherically-symmetric gravity. and is classically solvable. This, together with Let us start by considering the most generic the fact that it is easier to handle than the full 4D 2D diffeomorphism-invariant action yielding sec- theory or many other models, makes it a power- ond order differential equations for the metric g ful test-bench for many of the ideas in quantum and a scalar (dilaton) field Φ [2] gravity. There has been an extensive previous 1 p work on this model in the literature in the clas- S = d2x −|gj G ˆ sical and the quantum/semiclassical regime. 2 2 The CGHS action is × Y (Φ)R(g) + V (rΦ) ; Φ : (3.1) 1 2 p −2φ Sg-CGHS = d x −|gje Within this class we choose a subclass [4, 26, 27] 2G2 ˆ that is generic enough for our purposes, ab 2 × R + 4g @aφ∂bφ + 4λ ; (2.1) 1 2 p Sg-dil = d x −|gj where G is the 2-dimensional Newton constant, G2 ˆ 2 φ is the dilaton field and λ the cosmological con- 1 ab × Y (Φ)R(g) + g @aΦ@bΦ + V (Φ) : stant.
Load more

Recommended publications
  • Models of Phase Stability in Jackiw-Teitelboim Gravity
    PHYSICAL REVIEW D 100, 124061 (2019) Models of phase stability in Jackiw-Teitelboim gravity Arindam Lala* Instituto de Física, Pontificia Universidad Católica de Valparaíso, Casilla, 4059 Valparaiso, Chile † Dibakar Roychowdhury Department of Physics, Indian Institute of Technology Roorkee, Roorkee, 247667 Uttarakhand, India (Received 4 October 2019; published 31 December 2019) We construct solutions within Jackiw-Teitelboim (JT) gravity in the presence of nontrivial couplings between the dilaton and the Abelian 1-form where we analyze the asymptotic structure as well as the phase stability corresponding to charged black hole solutions in 1 þ 1 D. We consider the Almheiri-Polchinski model as a specific example within 1 þ 1 D JT gravity which plays a pivotal role in the study of Sachdev-Ye- Kitaev (SYK)/anti–de Sitter (AdS) duality. The corresponding vacuum solutions exhibit a rather different asymptotic structure than their uncharged counterpart. We find interpolating vacuum solutions with AdS2 in the IR and Lifshitz2 in the UV with dynamical exponent zdyn ¼ 3=2. Interestingly, the presence of charge also modifies the black hole geometry from asymptotically AdS to asymptotically Lifshitz with the same value of the dynamical exponent. We consider specific examples, where we compute the corresponding free energy and explore the thermodynamic phase stability associated with charged black hole solutions in 1 þ 1 D. Our analysis reveals the existence of a universal thermodynamic feature that is expected to reveal its immediate consequences on the dual SYK physics at finite density and strong coupling. DOI: 10.1103/PhysRevD.100.124061 I. INTRODUCTION AND MOTIVATIONS For the last couple of years, there has been a systematic For the last couple of decades, there had been consid- effort toward unveiling the dual gravitational counterpart erable efforts toward a profound understanding of the of the SYK model.
    [Show full text]
  • Exact Solutions and Critical Chaos in Dilaton Gravity with a Boundary
    Prepared for submission to JHEP INR-TH-2017-002 Exact solutions and critical chaos in dilaton gravity with a boundary Maxim Fitkevicha;b Dmitry Levkova Yegor Zenkevich1c;d;e aInstitute for Nuclear Research of the Russian Academy of Sciences, 60th October An- niversary Prospect 7a, Moscow 117312, Russia bMoscow Institute of Physics and Technology, Institutskii per. 9, Dolgoprudny 141700, Moscow Region, Russia cDipartimento di Fisica, Universit`adi Milano-Bicocca, Piazza della Scienza 3, I-20126 Milano, Italy dINFN, sezione di Milano-Bicocca, I-20126 Milano, Italy eNational Research Nuclear University MEPhI, Moscow 115409, Russia E-mail: [email protected], [email protected], [email protected] Abstract: We consider (1 + 1)-dimensional dilaton gravity with a reflecting dy- namical boundary. The boundary cuts off the region of strong coupling and makes our model causally similar to the spherically-symmetric sector of multidimensional gravity. We demonstrate that this model is exactly solvable at the classical level and possesses an on-shell SL(2; R) symmetry. After introducing general classical solution of the model, we study a large subset of soliton solutions. The latter describe reflec- tion of matter waves off the boundary at low energies and formation of black holes at energies above critical. They can be related to the eigenstates of the auxiliary inte- grable system, the Gaudin spin chain. We argue that despite being exactly solvable, the model in the critical regime, i.e. at the verge of black hole formation, displays arXiv:1702.02576v2 [hep-th] 17 Apr 2017 dynamical instabilities specific to chaotic systems. We believe that this model will be useful for studying black holes and gravitational scattering.
    [Show full text]
  • A New Look at the RST Model Jian-Ge Zhoua, F. Zimmerschieda, J
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by CERN Document Server A new lo ok at the RST mo del a a a,b Jian-Ge Zhou , F. Zimmerschied , J.{Q. Liang and a H. J. W. Muller{Ki rsten a Department of Physics, University of Kaiserslautern, P. O. Box 3049, D{67653 Kaiserslautern, Germany b Institute of Theoretical Physics, Shanxi University Taiyuan, Shanxi 030006, P. R. China and Institute of Physics, Academia Sinica, Beijing 100080, P. R. China Abstract The RST mo del is augmented by the addition of a scalar eld and a b oundary term so that it is well-p osed and lo cal. Expressing the RST action in terms of the ADM formulation, the constraint structure can b e analysed completely.It is shown that from the view p oint of lo cal eld theories, there exists a hidden dynamical eld in the RST mo del. Thanks to the presence of this hidden 1 dynamical eld, we can reconstruct the closed algebra of the constraints which guarantee the general invariance of the RST action. The resulting stress tensors T are recovered to b e true tensor quantities. Esp ecially, the part of the stress tensors for the hidden dynamical eld gives the precise expression for t . 1 At the quantum level, the cancellation condition for the total central charge is reexamined. Finally, with the help of the hidden dynamical eld , the fact 1 that the semi-classical static solution of the RST mo del has two indep endent parameters (P,M), whereas for the classical CGHS mo del there is only one, can b e explained.
    [Show full text]
  • Fourth Meeting on Constrained Dynamics and Quantum Gravity
    Fourth Meeting on Constrained Dynamics and Quantum Gravity Sardinia | September 2005 Mass and entropy of the exact string black hole speaker: Daniel Grumiller (DG) affiliation: Institute for Theoretical Physics, University of Leipzig, Augustusplatz 10-11, D-04109 Leipzig, Germany supported by an Erwin-Schr¨odinger fellowship, project J-2330-N08 of the Austrian Science Foundation (FWF) Based upon: DG, hep-th/0501208, hep-th/0506175 Outline 1. Motivation/Actions 2. The exact string black hole (ESBH) 3. Action for the ESBH 4. Mass and entropy of the ESBH 5. Loose ends 1 1. Motivation Why 2D? 2 1. Motivation Why 2D? dimensionally reduced models (spherical • symmetry) strings (2D target space) • integrable models (PSM) • models for BH physics (information loss) • study important conceptual problems with- out encountering insurmountable technical ones 2D gravity: useful toy model(s) for classi- ! cal and quantum gravity most prominent member not just a toy model: Schwarzschild Black Hole (\Hydrogen atom of General Relativity") 2-a Actions (2D dilaton gravity) EH: S = dDxp gR + surface Z − R: Ricci scalar g: determinant of metric gµν Physical degrees of freedom: D(D 3)=2 − JBD/scalar-tensor theories/low energy strings: S(2) = dDxp g XR U(X)( X)2 + 2V (X) − − r Z X: \dilaton field” U; V : (arbitrary) potentials \dilaton gravity in D dimensions" Often exponential representation: 2φ X = e− Extremely useful: First order action! In 2D: (1) a a S = XaT +XR+ (XaX U(X) + V (X)) ; Z Review: DG, W. Kummer, D. Vassilevich, hep-th/0204253 3 3. The exact string BH µ NLSM (target space metric: gµν, coordinates: x ) σ 2 ij µ ν S d ξp h gµνh @ x @ x + α φ + tachyon / − i j 0 R Z set B-field zero.
    [Show full text]
  • Black Holes and Thermodynamics-The First Half Century
    Black holes and thermodynamics — The first half century Daniel Grumiller, Robert McNees and Jakob Salzer Abstract Black hole thermodynamics emerged from the classical general relativis- tic laws of black hole mechanics, summarized by Bardeen–Carter–Hawking, to- gether with the physical insights by Bekenstein about black hole entropy and the semi-classical derivation by Hawking of black hole evaporation. The black hole entropy law inspired the formulation of the holographic principle by ’t Hooft and Susskind, which is famously realized in the gauge/gravity correspondence by Mal- dacena, Gubser–Klebanov–Polaykov and Witten within string theory. Moreover, the microscopic derivation of black hole entropy, pioneered by Strominger–Vafa within string theory, often serves as a consistency check for putative theories of quantum gravity. In this book chapter we review these developments over five decades, start- ing in the 1960ies. Introduction and Prehistory Introductory remarks. The history of black hole thermodynamics is intertwined with the history of quantum gravity. In the absence of experimental data capable of probing Planck scale physics the best we can do is to subject putative theories of quantum gravity to stringent consistency checks. Black hole thermodynamics pro- vides a number of highly non-trivial consistency checks. Perhaps most famously, arXiv:1402.5127v3 [gr-qc] 17 Mar 2014 Daniel Grumiller Institute for Theoretical Physics, Vienna University of Technology, Wiedner Hauptstrasse 8-10, A-1040 Vienna, Austria e-mail: [email protected]
    [Show full text]
  • Semi-Classical Black Hole Holography
    Dissertation for the degree of Doctor of Philosophy Semi-Classical Black Hole Holography Lukas Schneiderbauer School of Engineering and Natural Sciences Faculty of Physical Sciences Reykjavík, September 2020 A dissertation presented to the University of Iceland, School of Engineering and Natural Sciences, in candidacy for the degree of Doctor of Philosophy. Doctoral committee Prof. Lárus Thorlacius, advisor Faculty of Physical Sciences, University of Iceland Prof. Þórður Jónsson Faculty of Physical Sciences, University of Iceland Prof. Valentina Giangreco M. Puletti Faculty of Physical Sciences, University of Iceland Prof. Bo Sundborg Department of Physics, Stockholm University Opponents Prof. Veronika Hubeny University of California, Davis Prof. Mukund Rangamani University of California, Davis Semi-classical Black Hole Holography Copyright © 2020 Lukas Schneiderbauer. ISBN: 978-9935-9452-9-7 Author ORCID: 0000-0002-0975-6803 Printed in Iceland by Háskólaprent, Reykjavík, Iceland, September 2020. Contents Abstractv Ágrip (in Icelandic) vii Acknowledgementsx 1 Introduction1 2 Black Hole Model7 2.1 The Polyakov term . .8 2.2 The stress tensor . 11 2.3 Coherent matter states . 14 2.4 The RST term . 15 2.5 Equations of motion . 15 2.6 Black hole thermodynamics . 17 3 Page Curve 21 3.1 Generalized entropy . 24 4 Quantum Complexity 27 4.1 Complexity of black holes . 29 4.2 The geometric dual of complexity . 32 5 Conclusion 35 Bibliography 37 Articles 47 Article I ..................................... 49 iii Article II .................................... 67 Article III .................................... 99 iv Abstract This thesis discusses two aspects of semi-classical black holes. First, a recently improved semi-classical formula for the entanglement entropy of black hole radiation is examined.
    [Show full text]
  • Information Loss in the CGHS Model Fethi Mubin¨ Ramazanoglu˘
    Information Loss in the CGHS Model Fethi Mubin¨ Ramazanoglu˘ PRINCETON UNIVERSITY DEPARTMENT of PHYSICS ILQGS, 03/09/2010 collaborators Abhay Ashtekar, PennState Frans Pretorius, Princeton Information Loss in the CGHS Model Outline 1 A Quick Look at Informaton Loss 2 CGHS Model 3 Numerical Solution 4 Results: Macroscopic BH Finiteness of y− Bondi Mass and Hawking Radiation Diminishing of the Bondi Mass 5 Results: Planck Scale BH 6 Recent 7 Conclusions and Future 2 / 30 MFA Quantum Gravity Information Loss in the CGHS Model A Quick Look at Informaton Loss A Quick Overview of Information Loss I+ I+ L − R y 3 / 30 z− − − IL IR Fixed Background MFA Information Loss in the CGHS Model A Quick Look at Informaton Loss A Quick Overview of Information Loss I+ I+ L − R y 4 / 30 z− − − IL IR Fixed Background Quantum Gravity Information Loss in the CGHS Model A Quick Look at Informaton Loss A Quick Overview of Information Loss I+ I+ L − R y 5 / 30 z− − − IL IR Fixed Background MFA Quantum Gravity Information Loss in the CGHS Model CGHS Model Why CGHS Why 1+1 D? Conformal flatness Easy calculation at 1-loop: Trace anomaly ) Local action More manageable numerics Qualitatively similar to reduced 3+1 D, yet analytical solutions. 6 / 30 Information Loss in the CGHS Model CGHS Model Action and Classical Equations of Motion S(g; φ, f ) = 1 Z d2Ve−2φ R + 4gabr φr φ + 4κ2 G a b N 1 X Z − d2Vgabr f r f 2 a i b i i=1 S(4)(g; φ, f )= 1 Z d2Ve−2φ R + 2gabr φr φ + 2e−2φκ2 G a b N 1 X Z − d2Ve−φgabr f r f 2 a i b i i=1 Callan, Giddings,Harvey, Strominger, Phys.
    [Show full text]
  • Xavier Calmet Editor Quantum Aspects of Black Holes Fundamental Theories of Physics
    Fundamental Theories of Physics 178 Xavier Calmet Editor Quantum Aspects of Black Holes Fundamental Theories of Physics Volume 178 Series editors Henk van Beijeren Philippe Blanchard Paul Busch Bob Coecke Dennis Dieks Detlef Dürr Roman Frigg Christopher Fuchs Giancarlo Ghirardi Domenico J.W. Giulini Gregg Jaeger Claus Kiefer Nicolaas P. Landsman Christian Maes Hermann Nicolai Vesselin Petkov Alwyn van der Merwe Rainer Verch R.F. Werner Christian Wuthrich More information about this series at http://www.springer.com/series/6001 Xavier Calmet Editor Quantum Aspects of Black Holes 123 Editor Xavier Calmet Department of Physics and Astronomy University of Sussex Brighton UK ISBN 978-3-319-10851-3 ISBN 978-3-319-10852-0 (eBook) DOI 10.1007/978-3-319-10852-0 Library of Congress Control Number: 2014951685 Springer Cham Heidelberg New York Dordrecht London © Springer International Publishing Switzerland 2015 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. Exempted from this legal reservation are brief excerpts in connection with reviews or scholarly analysis or material supplied specifically for the purpose of being entered and executed on a computer system, for exclusive use by the purchaser of the work. Duplication of this publication or parts thereof is permitted only under the provisions of the Copyright Law of the Publisher’s location, in its current version, and permission for use must always be obtained from Springer.
    [Show full text]
  • The Factorization Problem in Jackiw-Teitelboim Gravity
    The factorization problem in Jackiw-Teitelboim gravity The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. Citation Harlow, Daniel and Daniel Jafferis. "The factorization problem in Jackiw-Teitelboim gravity." Journal of High Energy Physics 2020, 2 (February 2020): 177 © 2020 The Authors As Published https://doi.org/10.1007/JHEP02(2020)177 Publisher Springer Science and Business Media LLC Version Final published version Citable link https://hdl.handle.net/1721.1/128911 Terms of Use Creative Commons Attribution Detailed Terms https://creativecommons.org/licenses/by/4.0/ Published for SISSA by Springer Received: November 14, 2019 Accepted: February 12, 2020 Published: February 27, 2020 The factorization problem in Jackiw-Teitelboim gravity JHEP02(2020)177 Daniel Harlowa and Daniel Jafferisb aCenter for Theoretical Physics, Massachusetts Institute of Technology, Cambridge, MA 02138, U.S.A. bCenter for the Fundamental Laws of Nature, Harvard University, Cambridge, MA 02138, U.S.A. E-mail: [email protected], [email protected] Abstract: In this note we study the 1 + 1 dimensional Jackiw-Teitelboim gravity in Lorentzian signature, explicitly constructing the gauge-invariant classical phase space and the quantum Hilbert space and Hamiltonian. We also semiclassically compute the Hartle- Hawking wave function in two different bases of this Hilbert space. We then use these results to illustrate the gravitational version of the factorization problem of AdS/CFT: the Hilbert space of the two-boundary system tensor-factorizes on the CFT side, which appears to be in tension with the existence of gauge constraints in the bulk.
    [Show full text]
  • GR20/Amaldi10 — Abstract Book
    GR20/Amaldi10 | Abstract Book Local Organising Committee July 6, 2013 Contents A1 - Exact solutions and their interpretation3 Oral session...............................................3 Poster session.............................................. 12 A2 - Mathematical relativity and other progress in classical gravity theory 17 Oral session............................................... 17 Poster session.............................................. 24 A3 - Modified gravity theories 35 Oral session............................................... 35 Poster session.............................................. 43 A4 - Complex and conformal methods in classical and quantum gravity 51 Oral session............................................... 51 Poster session.............................................. 57 B1 - Relativistic astrophysics 59 Oral session............................................... 59 Poster session.............................................. 66 Joint session B2 and B4: Approximate solutions to Einstein equations, Methods and Applications' 74 Oral session............................................... 74 B2 - Numerical relativity and astrophysical applications 78 Oral session............................................... 78 Poster session.............................................. 86 B3 - Numerical relativity : methods, theoretical gravity and high energy applications 88 Oral session............................................... 88 Poster session.............................................. 94 B4 - Analytic approximations,
    [Show full text]
  • From Black Holes to Baby Universes in CGHS Gravity Arxiv:2103.13422V2
    From black holes to baby universes in CGHS gravity Victor Godeta and Charles Marteaub a International Centre for Theoretical Sciences (ICTS-TIFR), Tata Institute of Fundamental Research, Shivakote, Hesaraghatta, Bangalore 560089, India e-mail: [email protected] b Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 0C2, Canada e-mail: [email protected] ABSTRACT. We study CGHS\ gravity, a variant of the matterless Callan-Giddings- Harvey-Strominger model. We show that it describes a universal sector of the near hori- zon perturbations of non-extremal black holes in higher dimensions. In many respects this theory can be viewed as a flat space analog of Jackiw-Teitelboim gravity. The result for the Euclidean path integral implies that CGHS\ is dual to a Gaussian ensemble that we describe in detail. The simplicity of this theory allows us to compute exact quantities such as the quenched free energy and provides a useful playground to study baby universes, averages and factorization. In particular we derive a “wormhole = diagonal” identity. We also give evidence for the existence of a non-perturbative completion in terms of a matrix arXiv:2103.13422v2 [hep-th] 28 Jun 2021 model. Finally, flat wormhole solutions in this model are discussed. 2 1 Introduction3 1.1 Black hole near horizon dynamics . .3 1.2 Euclidean path integral in gravity . .5 1.3 Summary . .7 2 The CGHSd model8 2.1 Review of the model . .8 2.2 Boundary action . .9 2.3 Euclidean path integral . 13 3 Near horizon dynamics of non-extremal black holes 16 3.1 BTZ black hole .
    [Show full text]
  • Field-To-Particle Transition and Nonminimal Particles in Sigma Model, Dilaton Gravity and Gauged Supergravity
    25 October 2001 Physics Letters B 519 (2001) 111–120 www.elsevier.com/locate/npe Field-to-particle transition and nonminimal particles in sigma model, dilaton gravity and gauged supergravity Konstantin G. Zloshchastiev Department of Physics, National University of Singapore, Singapore 117542, Republic of Singapore and Department of Theoretical Physics, Dnepropetrovsk State University, Dnepropetrovsk 49050, Ukraine Received 19 July 2001; received in revised form 19 August 2001; accepted 28 August 2001 Editor: T. Yanagida Abstract The field-to-particle transition formalism is applied to the sigma model, and then to the 2D dilaton gravity and gauged supergravity 0-brane solutions. This approach yields the method of the consistent quantization in the vicinity of the nontrivial vacuum induced by a field solution, as well as the recipe of the nontrivial dynamical dimensional reduction which takes into account field fluctuations. It is explicitly shown that in all cases the end product is the so-called nonminimal point particle—an object whose action depends on the world-line curvature. Such objects are suspected to be common at early stages of evolution of the Universe. 2001 Elsevier Science B.V. All rights reserved. PACS: 04.60.Kz; 04.65.+e; 11.25.Sq; 11.27.+d; 12.60.Jv 1. Introduction plain bosonic string in the N-dimensional space–time. The remainder of that section is devoted to quantiza- The studies of the field-to-particle transition grew tion of the obtained effective action as a constrained up from the old program of constructing a theory mechanics with higher derivatives. There we discuss which does not contain matter as an external postu- the recent state of the theory and calculate the quantum lated entity but consider fields as sources of matter corrections to the mass of such a field/string-induced and the particles as special field configurations.
    [Show full text]