Late-time acceleration driven by shift-symmetric Galileon in the presence of torsion

Banerjee, Rabin; Chakraborty, Sumanta; Mukherjee, Prerana

doi:10.1103/physrevd.98.083506

Cited by 10 publications

(4 citation statements)

References 44 publications

(56 reference statements)

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“…Further, the presence of spacetime torsion itself modifies the gravitational Lagrangian and hence the field equations in a non-trivial manner. Even though some geometrical [56,57] and thermodynamical [48] consequences of the presence of spacetime torsion has been discussed at some length, unfortunately there have been very little discussions on what happens to the black hole entropy or, more precisely to the entropy-area relation as torsion is brought into the picture [51,58] (as an aside, the effect of spacetime torsion on cosmology has been discussed in [59][60][61]).…”

Section: Introductionmentioning

confidence: 99%

Noether current, black hole entropy and spacetime torsion

Chakraborty

Dey

2018

Physics Letters B

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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. *

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Section: Introductionmentioning

confidence: 99%

Noether current, black hole entropy and spacetime torsion

Chakraborty

Dey

2018

Physics Letters B

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“…We now wish to find a modified version of WDW in light of Eq. (7). In order to find the Hamiltonian, we first compute the conjugate momenta;…”

Section: Setupmentioning

confidence: 99%

“…Be that as it may, an overwhelming experimental results have been casting doubt on the standard model of cosmology based on GR [2][3][4]. Theories with torsion have recently gained ground as a promising extension to GR that would be in line with all the observationally successful results of GR in the regime of a vanishing torsion [5][6][7][8][9][10].…”

Section: Introductionmentioning

confidence: 99%

Quantum Cosmology with vector torsion

Kasem¹,

Khalil²

2020

Preprint

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We extend the treatment of quantum cosmology to a manifold with torsion. We adopt a model of Einstein-Cartan-Sciama-Kibble compatible with the cosmological principle. The universe wavefunction will be subject to a PT -symmetric Hamiltonian. With a vanishing energy-momentum tensor, the universe evolution in the semiclassical and classical regimes is shown to reflect a two-stage inflationary process induced by torsion.

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“…One of the main difficulties faced by these proposals is to ensure their consistency with the predictions of the ΛCDM model (and, more generally, of GR itself) in those scales where it is known to be observationally successful, which leaves little room for drastic alterations of the main principles upon which GR is built. A path to consistently explore the cosmological dynamics beyond that described in the ΛCDM model is the consideration of theories with torsion, a topic which has raised a renewed interest in the last few years [20][21][22][23][24][25][26][27][28][29]. The canonical model at this regard is the Einstein-Cartan-Sciama-Kibble (ECSK) theory, where the spacetime is endowed with a Riemann-Cartan (RC) geometry with curvature and torsion (for a quick glance on the main elements of this theory, see for instance [30]).…”

Section: Introductionmentioning

confidence: 99%

The cosmological principle in theories with torsion: the case of Einstein-Cartan-Dirac-Maxwell gravity

Cabral

Rubiera-García

2020

J. Cosmol. Astropart. Phys.

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We address the implementation of the cosmological principle, that is, the assumption of homogeneity and isotropy in the spatial distribution of matter in the Universe, within the context of Einstein-Cartan theory including minimal couplings of both Dirac and Maxwell fields to torsion. This theory gives rise to new physical effects in environments of high spin densities while leaving the vacuum dynamics unaffected. Our approach is to impose the cosmological principle from the onset to the geometrical degrees of freedom (metric and torsion functions), which constrains the torsion components and the corresponding correction terms in the Friedmann-like equations and in the resulting fermionic and bosonic (non-linear) dynamics. We derive the corresponding cosmological dynamics for the geometrical and matter degrees of freedom and discuss the validity of this approach.

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Late-time acceleration driven by shift-symmetric Galileon in the presence of torsion

Cited by 10 publications

References 44 publications

Noether current, black hole entropy and spacetime torsion

Noether current, black hole entropy and spacetime torsion

Quantum Cosmology with vector torsion

The cosmological principle in theories with torsion: the case of Einstein-Cartan-Dirac-Maxwell gravity

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