Noether current, black hole entropy and spacetime torsion
We show that the presence of spacetime torsion, unlike any other non-trivial modifications of the Einstein gravity, does not affect black hole entropy. The theory being diffeomorphism invariant leads to a Noether current and hence to a Noether charge, which can be associated to the heat content of t...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2018-11-01
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| Series: | Physics Letters B |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S0370269318307962 |
| _version_ | 1811295394115616768 |
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| author | Sumanta Chakraborty Ramit Dey |
| author_facet | Sumanta Chakraborty Ramit Dey |
| author_sort | Sumanta Chakraborty |
| collection | DOAJ |
| description | We show that the presence of spacetime torsion, unlike any other non-trivial modifications of the Einstein gravity, does not affect black hole entropy. The theory being diffeomorphism invariant leads to a Noether current and hence to a Noether charge, which can be associated to the heat content of the spacetime. Furthermore, the evolution of the spacetime inheriting torsion can be encoded in the difference between suitably defined surface and bulk degrees of freedom. For static spacetimes the surface and bulk degrees of freedom coincides, leading to holographic equipartition. In doing so one can see that the surface degrees of freedom originate from horizon area and it is clear that spacetime torsion never contributes to the surface degrees of freedom and hence neither to the black hole entropy. We further show that the gravitational Hamiltonian in presence of torsion does not inherit any torsion dependence in the boundary term and hence the first law originating from the variation of the Hamiltonian, relates entropy to area. This reconfirms our claim that torsion does not modify the black hole entropy. |
| first_indexed | 2024-04-13T05:32:46Z |
| format | Article |
| id | doaj.art-16a8461e6d154528ab951fbd616ca03e |
| institution | Directory Open Access Journal |
| issn | 0370-2693 |
| language | English |
| last_indexed | 2024-04-13T05:32:46Z |
| publishDate | 2018-11-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Physics Letters B |
| spelling | doaj.art-16a8461e6d154528ab951fbd616ca03e2022-12-22T03:00:23ZengElsevierPhysics Letters B0370-26932018-11-01786432441Noether current, black hole entropy and spacetime torsionSumanta Chakraborty0Ramit Dey1Department of Theoretical Physics, Indian Association for the Cultivation of Science, Kolkata 700032, IndiaDepartment of Theoretical Physics, Indian Association for the Cultivation of Science, Kolkata 700032, India; Department of Physics and Astronomy, The University of Western Ontario, London, ON N6A 3K7, Canada; Corresponding author.We show that the presence of spacetime torsion, unlike any other non-trivial modifications of the Einstein gravity, does not affect black hole entropy. The theory being diffeomorphism invariant leads to a Noether current and hence to a Noether charge, which can be associated to the heat content of the spacetime. Furthermore, the evolution of the spacetime inheriting torsion can be encoded in the difference between suitably defined surface and bulk degrees of freedom. For static spacetimes the surface and bulk degrees of freedom coincides, leading to holographic equipartition. In doing so one can see that the surface degrees of freedom originate from horizon area and it is clear that spacetime torsion never contributes to the surface degrees of freedom and hence neither to the black hole entropy. We further show that the gravitational Hamiltonian in presence of torsion does not inherit any torsion dependence in the boundary term and hence the first law originating from the variation of the Hamiltonian, relates entropy to area. This reconfirms our claim that torsion does not modify the black hole entropy.http://www.sciencedirect.com/science/article/pii/S0370269318307962 |
| spellingShingle | Sumanta Chakraborty Ramit Dey Noether current, black hole entropy and spacetime torsion Physics Letters B |
| title | Noether current, black hole entropy and spacetime torsion |
| title_full | Noether current, black hole entropy and spacetime torsion |
| title_fullStr | Noether current, black hole entropy and spacetime torsion |
| title_full_unstemmed | Noether current, black hole entropy and spacetime torsion |
| title_short | Noether current, black hole entropy and spacetime torsion |
| title_sort | noether current black hole entropy and spacetime torsion |
| url | http://www.sciencedirect.com/science/article/pii/S0370269318307962 |
| work_keys_str_mv | AT sumantachakraborty noethercurrentblackholeentropyandspacetimetorsion AT ramitdey noethercurrentblackholeentropyandspacetimetorsion |