Noether current, black hole entropy and spacetime torsion

Chakraborty, Sumanta; Dey, Ramit

doi:10.1016/j.physletb.2018.10.027

Cited by 23 publications

(20 citation statements)

References 69 publications

(93 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is consistent with the result derived for time-like geodesics and to leading order is identical to F . This provides yet another interpretation for the object R ab ℓ a ℓ b , abundant in thermodynamic description of gravity [28,[47][48][49][50][51]. Thus our analysis explicitly demonstrates that the Raychaudhuri equation associated with qmetric remains finite in the coincidence limit, implying avoidance of caustics.…”

Section: Coincidence Limit: Finiteness Of Raychaudhuri Equationsupporting

confidence: 55%

Raychaudhuri equation with zero point length

2019

Self Cite

View full text Add to dashboard Cite

The Raychaudhuri equation for a geodesic congruence in the presence of a zero-point length has been investigated. This is directly related to the small-scale structure of spacetime and possibly captures some quantum gravity effects. The existence of such a minimum distance between spacetime events modifies the associated metric structure and hence the expansion as well as its rate of change deviates from standard expectations. This holds true for any kind of geodesic congruences, including time-like and null geodesics. Interestingly, this construction works with generic spacetime geometry without any need of invoking any particular symmetry. In particular, inclusion of a zero-point length results into a non-vanishing cross-sectional area for the geodesic congruences even in the coincidence limit, thus avoiding formation of caustics. This will have implications for both time-like and null geodesic congruences, which may lead to avoidance of singularity formation in the quantum spacetime.

show abstract

Section: Coincidence Limit: Finiteness Of Raychaudhuri Equationsupporting

confidence: 55%

Raychaudhuri equation with zero point length

2019

Self Cite

View full text Add to dashboard Cite

show abstract

“…It is worth noting here that in Refs. [36][37][38] it is found that torsion does not contribute to black hole entropy in Riemann-Cartan spacetimes (see, however, Ref. [39]).…”

Section: Black Hole Entropymentioning

confidence: 99%

Noether charge and black hole entropy in teleparallel gravity

Hammad¹,

Dijamco²,

Torres-Rivas³

et al. 2019

Phys. Rev. D

View full text Add to dashboard Cite

The Noether charge associated to diffeomorphism invariance in teleparallel gravity is derived. It is shown that the latter yields the ADM mass of an asymptotically flat spacetime. The black hole entropy is then investigated based on Wald's prescription that relies on the Noether charge. It is shown that, like in general relativity, the surface gravity can be factored out from such a charge. Consequently, the similarity with the first law of thermodynamics implied by such an approach in general relativity does show up also in teleparallel gravity. It is found that, based on the expression of the first law of black hole mechanics, which is preserved in teleparallel gravity, entropy can thus be extracted from such a Noether charge. The resulting entropy can very naturally be expressed as a volume integral, though. As such, it is shown that the conformal issue that plagues the entropy-area law within general relativity does not arise in teleparallel gravity based on Wald's approach. The physics behind these features is discussed.

show abstract

“…The present paper attempts to unify and expand certain aspects of previous works [17][18][19][20][21][22][23][24][25][26][27] dealing with metric-Palatini and tetrad-Palatini, focusing on the comparison of both formulations and the treatment of boundaries. In this regard, we would like to highlight the pioneering work by Obukhov [28], where he introduced the appropriate surface terms for Palatini gravity.…”

Section: Introductionmentioning

confidence: 99%

Palatini gravity with nonmetricity, torsion, and boundaries in metric and connection variables

Margalef-Bentabol

Varo²,

Villaseñor³

2021

Phys. Rev. D

View full text Add to dashboard Cite

We prove the equivalence in the covariant phase space of the metric and connection formulations for Palatini gravity, with nonmetricity and torsion, on a spacetime manifold with boundary. To this end, we will rely on the cohomological approach provided by the relative bicomplex framework. Finally, we discuss some of the physical implications derived from this equivalence in the context of singularity identification through curvature invariants.

show abstract

Noether current, black hole entropy and spacetime torsion

Cited by 23 publications

References 69 publications

Raychaudhuri equation with zero point length

Raychaudhuri equation with zero point length

Noether charge and black hole entropy in teleparallel gravity

Palatini gravity with nonmetricity, torsion, and boundaries in metric and connection variables

Contact Info

Product

Resources

About