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Related papers: Non-zero torsion and late cosmology

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Several recent investigations have shown that there is a holographic relationship between the bulk degrees of freedom and the surface degrees of freedom in the spacetime. Furthermore, the entropy on the horizon can produce an entropic force…

General Relativity and Quantum Cosmology · Physics 2021-07-23 Fei-Quan Tu , Yi-Xin Chen , Qi-Hong Huang

In this paper, we investigate the validity of the generalized second law (GSL) of thermodynamics in flat FRW chameleon cosmology where the boundary of the universe is assumed to be enclosed by the dynamical apparent horizon. It has been…

General Relativity and Quantum Cosmology · Physics 2015-05-28 H. Farajollahi , A. Salehi , F. Tayebi

A perfect fluid, spatially flat cosmology in a $f(T)$ model, derived from a recently proposed general Born-Infeld type theory of gravity is studied. Four dimensional cosmological solutions are obtained assuming the equation of state…

General Relativity and Quantum Cosmology · Physics 2014-12-04 Soumya Jana

As evidenced by a great number of works, it is common practice to assume that the Universe is flat. However, the majority of studies which make use of observational data to constrain the curvature density parameter are premised on the…

General Relativity and Quantum Cosmology · Physics 2019-07-18 Christine R. Farrugia , Joseph Sultana

We consider spatially homogeneous and isotropic cosmologies with non-zero torsion. Given the high symmetry of these universes, we adopt a specific form for the torsion tensor that preserves the homogeneity and isotropy of the spatial…

General Relativity and Quantum Cosmology · Physics 2019-05-01 D. Kranas , C. G. Tsagas , J. D. Barrow , D. Iosifidis

Thermodynamics on the cosmological apparent horizon of a flat Friedmann-Lemaitre-Robertson-Walker metric has been investigated with Bekenstein entropy and Hawking temperature on the horizon, and Unruh temperature for the fluid inside the…

General Relativity and Quantum Cosmology · Physics 2016-07-15 Subhajit Saha

We investigate a flat FLRW-model in $f(R,T)$-gravity, which includes the quadratic variation in scalar curvature $R$ and the linear term of the trace of the stress-energy tensor $T$. In turn, we establish the model has the behaviour of the…

General Relativity and Quantum Cosmology · Physics 2022-08-10 J. K. Singh , Akanksha Singh , G. K. Goswami , J. Jena

A one-component dark energy fluid model of the late universe is considered ($w<-1$) when the fluid, initially assumed laminar, makes a transition into a turbulent state of motion. Spatial isotropy is assumed so that only the bulk…

General Relativity and Quantum Cosmology · Physics 2016-03-02 Iver Brevik

In the present work we derive an exact solution of an isotropic and homogeneous Universe governed by $f(T)$ gravity. We show how the torsion contribution to the FRW cosmology can provide a \textit{unique} origin for both early and late…

General Relativity and Quantum Cosmology · Physics 2016-10-19 G. G. L. Nashed , W. El Hanafy

The present work shows that the second law of thermodynamics gets naturally satisfied during the entire cosmic evolution of the universe starting from inflation to the late dark energy era, without imposing any exotic condition. This makes…

General Relativity and Quantum Cosmology · Physics 2025-02-05 Sergei D. Odintsov , Tanmoy Paul , Soumitra SenGupta

In this paper, we study the nonlinear electrodynamics in the framework of $f(T)$ gravity for FRW universe along with dust matter, magnetic and torsion contributions. We evaluate the equation of state and deceleration parameters to explore…

General Relativity and Quantum Cosmology · Physics 2015-06-19 M. Sharif , Shamaila Rani

We explain an accelerated expansion of the present universe, suggested from observations of supernovae of type Ia at high redshift, by introducing an anti-frictional force that is self-consistently exerted on the particles of the cosmic…

Astrophysics · Physics 2008-11-26 Winfried Zimdahl , Dominik J. Schwarz , Alexander B. Balakin , Diego Pavon

The paper deals with generalized Rastall theory of gravity and its cosmological consequences in the background of homogeneous and isotropic flat FLRW model with perfect fluid as the matter context. The model shows a non singular era…

General Relativity and Quantum Cosmology · Physics 2018-10-29 Dipanjana Das , Sourav Dutta , Subenoy Chakraborty

The paper deals with the mechanism of particle creation in the framework of irreversible thermodynamics. The second order non-equilibrium thermodynamical prescription of Israel and Stewart has been presented with particle creation rate,…

General Relativity and Quantum Cosmology · Physics 2016-05-04 Subenoy Chakraborty , Subhajit Saha

The paper deals with cosmological solutions describing different phases of the Universe for the homogeneous and isotropic FLRW model of the Universe with torsion. Normally, torsion field is not suitable for maximally symmetric space time…

General Relativity and Quantum Cosmology · Physics 2020-10-30 Akash Bose , Subenoy Chakraborty

It is shown that the tunneling effect in quantum cosmology is possible not only at the very beginning or the very end of the evolution, but also at the moment of maximum expansion of the universe. A positive curvature expanding Friedmann…

General Relativity and Quantum Cosmology · Physics 2009-10-28 M. P. Dabrowski , A. L. Larsen

We discuss the energy density,temperature and entropy of dark matter (DM) and dark energy (DE) as functions of the scale factor $a$ in an expanding universe. In a model of non-interacting dark components we repeat a derivation from…

General Relativity and Quantum Cosmology · Physics 2017-03-27 Z. Haba

It was shown by Tsallis and Cirto that thermodynamical entropy of a gravitational system such as black hole must be generalized to the non-additive entropy, which is given by $S_h=\gamma A^{\beta}$, where $A$ is the horizon area and $\beta$…

General Relativity and Quantum Cosmology · Physics 2018-09-26 Ahmad Sheykhi

Building on the recent solution for the spectrum of the non-commutative well in two dimensions, the thermodynamics that follows from it is computed. In particular the focus is put on an ideal fermion gas confined to such a well. At low…

High Energy Physics - Theory · Physics 2008-12-18 F G Scholtz , J Govaerts

We describe non-flat standard Friedmann cosmology of canonical scalar field with barotropic fluid in form of non-linear Schr\"{o}dinger-type (NLS) formulation in which all cosmological dynamical quantities are expressed in term of…

General Relativity and Quantum Cosmology · Physics 2014-11-18 Theerakarn Phetnora , Roongtum Sooksan , Burin Gumjudpai
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