Abstract
The relevance of gravitational boundary degrees of freedom and their dynamics in gravity quantization and black hole information has been explored in a series of recent works. In this work we further progress by focusing keenly on the genuine gravitational boundary degrees of freedom as the origin of black hole entropy. Wald’s entropy formula is scrutinized, and the reason that Wald’s formula correctly captures the entropy of a black hole examined. Afterwards, limitations of Wald’s method are discussed; a coherent view of entropy based on boundary dynamics is presented. The discrepancy observed in the literature between holographic and Wald’s entropies is addressed. We generalize the entropy definition so as to handle a time-dependent black hole. Large gauge symmetry plays a pivotal role. Non-Dirichlet boundary conditions and gravitational analogues of Coleman-De Luccia bounce solutions are central in identifying the microstates and differentiating the origins of entropies associated with different classes of solutions. The result in the present work leads to a view that black hole entropy is entanglement entropy in a thermodynamic setup.
Similar content being viewed by others
Notes
For how the worldvolume theory manifests, see sect. 3.3 of [5].
In this work we use the setup only at a conceptual level. See [25] for a recent analysis in which BHI was studied by employing the setup.
In some of the comments, replacing LGS by asymptotic symmetry would be more appropriate; we will not be concerned with this distinction.
In a Hartle-Hawking vacuum, for instance, the boundary degrees of freedom are excited. Since a Dirichlet boundary condition was always assumed, this raises a question on internal consistency of the analysis.
Indeed it is well known that it is Unruh vacuum that describes a decaying BH. The Unruh vacuum was obtained by carefully conducting perturbative analysis around a collapsing solution. Although it shuold be possible to consider a bounce solution associated with decay of Unruh vacuum, the analysis will enevitably be more complicated. To some degree, the simplification involved is analogous to the one achieved by examining an Unruh effect, instead of Unruh vacuum, for BH decay.
This is so in the component notation. In the coordinate-free notation, tensor types are preserved both by Lie and covariant derivatives (but not by a covariant differential) [47].
Another way to see this is through a path integral: the measure should ultimately be over the physical states, which have support on the boundary [40].
Strictly speaking, we believe that the degrees of freedom here should include those within the stretched horizon.
The singularity at the EH is usually referred to as a ‘coordinate singularity.’ All this means is that it is not a curvature singularity. To our view the term coordinate singularity is misleading at the quantum level in that it gives an impression that the singularity is not physical. If, for instance, a non-smooth EH turns out to be real, which we anticipate, the singularity will be very physical, though not a curvature singularity.
In general, this is not strictly true since \(\sqrt{-g}\) is a tensor density. However, with \(\nabla _\mu \xi ^\mu =0\), the quantities under consideration do transform as scalars.
Although the original Wald’s definition requires the presence of a Killing vector, the charge was also given in subsequent works by an expression based on a functional derivative with respect to the Riemann tensor. The present result implies that a formal entropy calculation based on such a definition will not reproduce the entropy based on an Euclidean action.
References
Hawking, S. W.: Particle Creation by Black Holes, Commun. Math. Phys. 43, 199 (1975) Erratum: [Commun. Math. Phys. 46, 206 (1976)]. https://doi.org/10.1007/BF02345020,https://doi.org/10.1007/BF01608497
Hawking, S.W.: Breakdown of predictability in gravitational collapse. Phys. Rev. D 14, 2460–2473 (1976). https://doi.org/10.1103/PhysRevD.14.2460
Buoninfante, L., Di Filippo, F., Mukohyama, S.: On the assumptions leading to the information loss paradox. J. High Energy Phys. 2021(10), 1–26 (2021). https://doi.org/10.1007/JHEP10(2021)081
Solodukhin, S.N.: Entanglement entropy of black holes. Living Rev. Rel. 14, 8 (2011). https://doi.org/10.12942/lrr-2011-8
Hatefi, E., Nurmagambetov, A.J., Park, I.Y.: ADM reduction of IIB on \(mathcal H ^{p, q}\) to dS braneworld. JHEP 04, 170 (2013). https://doi.org/10.1007/JHEP04(2013)170
Park, I.Y.: Foliation-based quantization and black hole information. Class. Quant. Grav. 34(24), 245005 (2017). https://doi.org/10.1088/1361-6382/aa9602
Park, I.Y.: Boundary dynamics in gravitational theories. JHEP 07, 128 (2019). https://doi.org/10.1007/JHEP07(2019)128
Park, I.Y.: Black hole evolution in a quantum-gravitational framework. PTEP 2021(6), 063B03 (2021). https://doi.org/10.1093/ptep/ptab045
Coleman, S.R., De Luccia, F.: Gravitational effects on and of vacuum decay. Phys. Rev. D 21, 3305 (1980). https://doi.org/10.1103/PhysRevD.21.3305
Ambrus, M., Hajicek, P.: Quantum superposition principle and gravitational collapse: scattering times for spherical shells. Phys. Rev. D 72, 064025 (2005). https://doi.org/10.1103/PhysRevD.72.064025
Haggard, H.M., Rovelli, C.: Quantum-gravity effects outside the horizon spark black to white hole tunneling. Phys. Rev. D 92(10), 104020 (2015). https://doi.org/10.1103/PhysRevD.92.104020
Christodoulou, M., Rovelli, C., Speziale, S., Vilensky, I.: Planck star tunneling time: an astrophysically relevant observable from background-free quantum gravity. Phys. Rev. D 94(8), 084035 (2016). https://doi.org/10.1103/PhysRevD.94.084035
Bianchi, E., Christodoulou, M., D’Ambrosio, F., Haggard, H.M., Rovelli, C.: White holes as remnants: a surprising scenario for the end of a black hole. Class. Quant. Grav. 35(22), 225003 (2018). https://doi.org/10.1088/1361-6382/aae550
Ben, Achour J., Uzan, J.P.: Bouncing compact objects. Part II: effective theory of a pulsating planck star. Phys. Rev. D 102, 124041 (2020). https://doi.org/10.1103/PhysRevD.102.124041
Ben Achour, J., Brahma, S., Mukohyama, S., Uzan, J.P.: Towards consistent black-to-white hole bounces from matter collapse. JCAP 09, 020 (2020). https://doi.org/10.1088/1475-7516/2020/09/020
Malafarina, D.: Classical collapse to black holes and quantum bounces: a review. Universe 3(2), 48 (2017). https://doi.org/10.3390/universe3020048
Park, I.Y.: Fundamental versus solitonic description of D3-branes. Phys. Lett. B 468, 213–218 (1999). https://doi.org/10.1016/S0370-2693(99)01216-2
Higuchi, A.: Quantum linearization instabilities of de sitter space-time 1. Class. Quant. Grav. 8, 1961–1981 (1991). https://doi.org/10.1088/0264-9381/8/11/009
Page, D.N.: Information in black hole radiation. Phys. Rev. Lett. 71, 3743–3746 (1993). https://doi.org/10.1103/PhysRevLett.71.3743
Kay, B.S.: Matter-gravity entanglement entropy and the information loss puzzle. High Energy Phys Theory (2022). https://doi.org/10.48550/arXiv.2206.07445
Kay, B.S.: Entropy defined, entropy increase and decoherence understood, and some black hole puzzles solved. High Energy Phys Theory (1998). https://doi.org/10.48550/arXiv.hep-th/980217
Kay, B.S.: Decoherence of macroscopic closed systems within Newtonian quantum gravity. Class. Quant. Grav. 15, L89–L98 (1998). https://doi.org/10.1088/0264-9381/15/12/003
Kay, B.S.: Modern foundations for thermodynamics and the stringy limit of black hole equilibria. High Energy Phys Theory (2012). https://doi.org/10.48550/arXiv.1209.5110
Kay, B.S.: On the origin of thermality. Stat. Mech. (2012). https://doi.org/10.48550/arXiv.1209.5215
Saini, A., Stojkovic, D.: Radiation from a collapsing object is manifestly unitary. Phys. Rev. Lett. 114(11), 111301 (2015). https://doi.org/10.1103/PhysRevLett.114.11130
Wald, R.M.: Black hole entropy is the noether charge. Phys. Rev. D 48(8), R3427–R3431 (1993). https://doi.org/10.1103/PhysRevD.48.R3427
Gibbons, G.W., Hawking, S.W.: Action integrals and partition functions in quantum gravity. Phys. Rev. D 15, 2752–2756 (1977). https://doi.org/10.1103/PhysRevD.15.2752
Almheiri, A., Marolf, D., Polchinski, J., Sully, J.: Black holes: complementarity or firewalls? JHEP 02, 062 (2013). https://doi.org/10.1007/JHEP02(2013)062
Hung, L.Y., Myers, R.C., Smolkin, M.: On holographic entanglement entropy and higher curvature gravity. JHEP 04, 025 (2011). https://doi.org/10.1007/JHEP04(2011)025
Astaneh, A.F., Patrushev, A., Solodukhin, S.N.: Entropy vs gravitational action: do total derivatives matter? High Energy Phys. Theory (2014). https://doi.org/10.48550/arXiv.1411.0926
Faraji Astaneh, A., Patrushev, A., Solodukhin, S.N.: Entropy discrepancy and total derivatives in trace anomaly. Phys. Lett. B 751, 227–232 (2015). https://doi.org/10.1016/j.physletb.2015.10.036
Faraji Astaneh, A., Solodukhin, S.N.: The wald entropy and 6d conformal anomaly. Phys. Lett. B 749, 272–277 (2015). https://doi.org/10.1016/j.physletb.2015.07.077
Park, I.Y.: Hypersurface foliation approach to renormalization of ADM formulation of gravity. Eur. Phys. J. C 75(9), 459 (2015). https://doi.org/10.1140/epjc/s10052-015-3660-x
Park, I.: Foliation-based approach to quantum gravity and applications to astrophysics. Universe 5(3), 71 (2019). https://doi.org/10.3390/universe5030071
Burda, P., Gregory, R., Moss, I.: Vacuum metastability with black holes. JHEP 08, 114 (2015). https://doi.org/10.1007/JHEP08(2015)114
Braunstein, S.L., Pirandola, S., Życzkowski, K.: Better late than never: information retrieval from black holes. Phys. Rev. Lett. 110(10), 101301 (2013). https://doi.org/10.1103/PhysRevLett.110.101301
Mathur, S.D.: The information paradox: a pedagogical introduction. Class. Quant. Grav. 26, 224001 (2009). https://doi.org/10.1088/0264-9381/26/22/224001
Nurmagambetov, A.J., Park, I.Y.: Quantum-induced trans-Planckian energy near horizon. JHEP 05, 167 (2018). https://doi.org/10.1007/JHEP05(2018)167
Nurmagambetov, A.J., Park, I.Y.: Quantum-gravitational trans-Planckian radiation by a rotating black hole. Fortsch. Phys. 69, 10 (2021). https://doi.org/10.1002/prop.202100064
Park, I.Y.: Lagrangian constraints and renormalization of 4D gravity. JHEP 04, 053 (2015). https://doi.org/10.1007/JHEP04(2015)053
Park, I.Y.: One-loop renormalization of a gravity-scalar system. Eur. Phys. J. C 77(5), 337 (2017). https://doi.org/10.1140/epjc/s10052-017-4896-4
Park, I.Y.: Revisit of renormalization of Einstein-Maxwell theory at one-loop. PTEP 2021(1), 013B03 (2021). https://doi.org/10.1093/ptep/ptaa167
Nishioka, T., Ryu, S., Takayanagi, T.: Holographic entanglement entropy: an overview. J. Phys. A 42, 504008 (2009). https://doi.org/10.1088/1751-8113/42/50/504008
Azeyanagi, T., Compere, G., Ogawa, N., Tachikawa, Y., Terashima, S.: Higher-derivative corrections to the asymptotic virasoro symmetry of 4d Extremal black holes. Prog. Theor. Phys. 122, 355–384 (2009). https://doi.org/10.1143/PTP.122.355
Liu, H.S., Lu, H.: A note on Kerr/CFT and Wald entropy discrepancy in high derivative gravities. JHEP 07, 213 (2021). https://doi.org/10.1007/JHEP07(2021)213
Ma, L., Pang, Y., Lu, H.: Improved wald formalism and first law of dyonic black strings with mixed Chern-Simons terms. J. High Energy Phys. 2022(10), 1–25 (2022)
Kobayashi, S., Nomizu, K.: Foundations of differential geometry. Interscience Publisher, Hoboken (1963)
Krishnan, C., Kumar, K.V.P., Raju, A.: An alternative path integral for quantum gravity. JHEP 10, 043 (2016). https://doi.org/10.1007/JHEP10(2016)043
Sakurai, J.J.: Modern Quantum Mechanics. The Benjamin/Cummings Publishing Company, San Francisco (1985)
Hawking, S.W., Horowitz, G.T.: The gravitational Hamiltonian, action, entropy and surface terms. Class. Quant. Grav. 13, 1487–1498 (1996). https://doi.org/10.1088/0264-9381/13/6/017
Kabat, D.N.: Black hole entropy and entropy of entanglement. Nucl. Phys. B 453, 281–299 (1995). https://doi.org/10.1016/0550-3213(95)00443-V
Solodukhin, S.N.: Newton constant, contact terms and entropy. Phys. Rev. D 91(8), 084028 (2015). https://doi.org/10.1103/PhysRevD.91.084028
Poisson, E.: A relativists’ toolkit, Cambridge (2004)
Padmanabhan, T.: Thermodynamical aspects of gravity: new insights. Rept. Prog. Phys. 73, 046901 (2010). https://doi.org/10.1088/0034-4885/73/4/046901
Rovelli, C.: Black hole entropy from loop quantum gravity. Phys. Rev. Lett. 77, 3288–3291 (1996). https://doi.org/10.1103/PhysRevLett.77.3288
Solodukhin, S.N.: Conformal description of horizon’s states. Phys. Lett. B 454, 213–222 (1999). https://doi.org/10.1016/S0370-2693(99)00398-6
Misner, C.W., Thorne, K.S., Wheeler, J.A.: Gravitation. W. H. Freeman and Company, New York (1973)
Author information
Authors and Affiliations
Corresponding author
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
About this article
Cite this article
Park, I.Y. Black Hole Entropy from Non-dirichlet Sectors, and a Bounce Solution. Found Phys 53, 74 (2023). https://doi.org/10.1007/s10701-023-00719-5
Received:
Accepted:
Published:
DOI: https://doi.org/10.1007/s10701-023-00719-5