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We apply the holographic principle in the cosmological context through the nonadditive Tsallis entropy, used to describe the thermodynamic properties of nonstandard statistical systems such as the gravitational ones. Assuming the future…

General Relativity and Quantum Cosmology · Physics 2019-05-29 Rocco D'Agostino

Thermodynamics-Gravity conjecture implies that there is a deep connection between the gravitational field equations and the first law of thermodynamics. Therefore, any modification to the entropy expression, directly modifies the field…

General Relativity and Quantum Cosmology · Physics 2023-04-10 Ahmad Sheykhi , Maral Sahebi Hamedan

We investigate a spatially flat Friedmann-Robertson-Walker (FRW) cosmological model with cold dark matter coupled to a dark energy which is given by the modified holographic Ricci cutoff. The interaction used is linear in both dark energy…

General Relativity and Quantum Cosmology · Physics 2012-06-07 Mónica I. Forte , Martín G. Richarte

We consider the angular power spectrum in a finite universe with different boundary conditions and perform a fit to the CMB, LSS and supernova data. A finite universe could be the consequence of a holographic constraint, giving rise to an…

Astrophysics · Physics 2010-12-09 Kari Enqvist , Steen Hannestad , Martin S. Sloth

The evolution of a flat, isotropic and homogeneous universe is studied. The background geometry in the early phases of the universe is conjectured to be filled with causal bulk viscous cosmological fluid and dark energy. The energy density…

General Relativity and Quantum Cosmology · Physics 2012-04-23 A. Tawfik

In this work we investigate the holographic dark energy models with slowly time-varying model parameter defined based on the current Hubble horizon length scale. While the previous studies on the three popular holographic dark energy models…

General Relativity and Quantum Cosmology · Physics 2019-05-07 Mohammad Malekjani , Mehdi Rezaei , Iman A. Akhlaghi

The problem of reproducing dark energy effects is reviewed here with particular interest devoted to cosmography. We summarize some of the most relevant cosmological models, based on the assumption that the corresponding barotropic equations…

General Relativity and Quantum Cosmology · Physics 2013-12-09 Salvatore Capozziello , Mariafelicia De Laurentis , Orlando Luongo , Alan Cosimo Ruggeri

We consider the problem of the nature and possible types of spacetime singularities that can form during the evolution of \emph{FRW} universes in general relativity. We show that by using, in addition to the Hubble expansion rate and the…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Spiros Cotsakis , Ifigeneia Klaoudatou

Based on generalized holographic formalism, we establish a holographic realization of constant roll inflation during the early universe, where the corresponding cut-off depends on the Hubble parameter and its derivatives (up to the second…

General Relativity and Quantum Cosmology · Physics 2023-05-31 Shin'ichi Nojiri , Sergei D. Odintsov , Tanmoy Paul

We explore the cosmological models of the late-time universe based on the holographic principle, taking into account the properties of the viscosity of the dark fluid. We use the mathematical formalism of generalized infrared cutoff…

General Relativity and Quantum Cosmology · Physics 2021-08-11 I. Brevik , A. V. Timoshkin

By using the holographic hypothesis and Kaniadakis generalized entropy, which is based on relativistic statistical theory and modified Boltzmann-Gibbs entrory, we build Kaniadakis holographic dark energy (DE) model in the Brans-Dicke…

High Energy Physics - Theory · Physics 2022-10-26 S. Ghaffari

We study cosmological evolution in a flat FLRW spacetime in the context of modified STEGR gravity or $f(Q)$, using an exponential two-parameter model which represents a smooth perturbative expansion around the $\Lambda$CDM model. The…

General Relativity and Quantum Cosmology · Physics 2025-04-15 Ivan R. Vasquez , A. Oliveros

We challenge the widely held belief that the cosmological principle is an obvious consequence of the observed isotropy of the cosmic microwave background radiation, combined with the Copernican principle. We perform a detailed analysis of a…

Astrophysics · Physics 2009-10-31 R. K. Barrett , C. A. Clarkson

In this work, we investigate the cosmological dynamics of an anisotropic Universe within the framework of $f(R,T)$ gravity by incorporating pressureless dark matter and the dark energy models. The analysis is carried out in a Bianchi type-I…

General Relativity and Quantum Cosmology · Physics 2026-05-13 S. H. Shekh , N. Myrzakulov , Anirudh Pradhan , M. Zeyauddin

Several problematical epochs in cosmology, including the recent period of structure formation (and acceleration), require us to understand cosmic evolution during times when the basis of FRW expansion, the cosmological principle, does not…

Astrophysics · Physics 2007-05-23 Brett Bochner

We propose an infrared cut-off for the holographic density which incorporates among others a constant term, that produces the effect of the cosmological constant, improving the results of previously considered holographic models based on…

High Energy Physics - Theory · Physics 2011-01-26 L. N. Granda

In this work we investigate the spherical collapse model in flat FRW dark energy universes. We consider the Holographic Dark Energy (HDE) model as a dynamical dark energy scenario with a slowly time-varying equation-of-state (EoS) parameter…

General Relativity and Quantum Cosmology · Physics 2015-01-27 Tayebe Naderi , Mohammad Malekjani , Francesco Pace

Landauer's principle and the Holographic principle are used to derive the holographic information energy contribution to the Universe. Information energy density has increased with star formation until sufficient to start accelerating the…

Cosmology and Nongalactic Astrophysics · Physics 2011-05-24 Michael Paul Gough

We investigate the viability of Tsallis holographic dark energy (THDE) models, focusing on the role of the infrared (IR) cutoff in the growth of cosmic structures. Considering two commonly used choices of the cutoff, the particle horizon…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-24 Biswajit Das

Inflationary cosmology predicts that the particle horizon should be generically much bigger than the present-day Hubble radius, $1/H_0$. This implies a special regime of super-Hubble scale energy density fluctuations imprinted on the cosmic…

Astrophysics · Physics 2009-10-30 Arjun Berera , Li-Zhi Fang , Gary Hinshaw
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