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Related papers: Barrow Cosmology and Big-Bang Nucleosynthesis

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We use Big Bang Nucleosynthesis (BBN) data in order to impose constraints on the exponent of Barrow entropy. The latter is an extended entropy relation arising from the incorporation of quantum-gravitational effects on the black-hole…

General Relativity and Quantum Cosmology · Physics 2021-02-19 John D. Barrow , Spyros Basilakos , Emmanuel N. Saridakis

We study the inflationary era of the Universe in a modified cosmological scenario based on the gravity-thermodynamics conjecture with Barrow entropy instead of the usual Bekenstein-Hawking one. The former arises from the effort to account…

General Relativity and Quantum Cosmology · Physics 2025-03-25 Giuseppe Gaetano Luciano

We investigate the cosmological consequences of the modified Friedmann equations when the entropy associated with the apparent horizon, given by Barrow entropy, $S\sim A^{1+\delta/2}$, where $0\leq\delta\leq1$, represents the amount of the…

General Relativity and Quantum Cosmology · Physics 2023-01-18 Ahmad Sheykhi

Inspired by the Covid-$19$ virus structure, Barrow argued that quantum-gravitational effects may introduce intricate, fractal features on the black hole horizon [Phys. Lett. B {\bf808} (2020) 135643]. In this viewpoint, black hole entropy…

General Relativity and Quantum Cosmology · Physics 2021-06-09 Ahmad Sheykhi

Taking into account a fractal structure for the black hole horizon, Barrow argued that the area law of entropy is modified due to quantum-gravitational effects (Barrow in Phys Lett B 808:135643,…

General Relativity and Quantum Cosmology · Physics 2022-05-20 Mahnaz Asghari , Ahmad Sheykhi

Modified cosmology based on Barrow entropy arises from the gravity-thermodynamics conjecture, in which the standard Bekenstein-Hawking entropy is replaced by the Barrow entropy of quantum-gravitational origin, characterized by the Barrow…

General Relativity and Quantum Cosmology · Physics 2025-09-08 Giuseppe Gaetano Luciano , Andronikos Paliathanasis , Emmanuel N. Saridakis

We investigate the generation of baryon asymmetry from the corrections brought about in the Friedman equations due to Barrow entropy. In particular, by applying the gravity-thermodynamics conjecture one obtains extra terms in the Friedmann…

General Relativity and Quantum Cosmology · Physics 2022-06-28 Giuseppe Gaetano Luciano , Emmanuel N. Saridakis

We revisit agegraphic dark energy (ADE) model when the entropy associated with the apparent horizon is in the form of Barrow entropy, $S\sim A^{1+\delta/2}$, where $0\leq\delta\leq1$ indicates the amount of the quantum-gravitational…

General Relativity and Quantum Cosmology · Physics 2023-05-18 A. Sheykhi , S. Ghaffari

We present modified cosmological scenarios that arise from the application of the "gravity-thermodynamics" conjecture, using the Barrow entropy instead of the usual Bekenstein-Hawking one. The former is a modification of the black hole…

General Relativity and Quantum Cosmology · Physics 2020-07-22 Emmanuel N. Saridakis

Barrow proposed that the area law of the horizon entropy might receive a "fractal correction" $S\propto A^{1+\Delta/2}$ due to quantum gravitational effects, with $0\leqslant \Delta \leqslant 1$ measures the deviation from the standard area…

General Relativity and Quantum Cosmology · Physics 2022-12-14 Sofia Di Gennaro , Hao Xu , Yen Chin Ong

We apply the full set of most update dynamical and geometrical data in cosmology to the nonextensive Barrow entropic holographic dark energy. We show that the data point towards an extensive Gibbs-like entropic behaviour for the…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-22 Tomasz Denkiewicz , Vincenzo Salzano , Mariusz P. Dabrowski

Both the Barrow and Tsallis $\delta$ entropies are one-parameter generalizations of the black-hole entropy, with the same microcanonical functional form. The ensuing deformation is quantified by a dimensionless parameter $\Delta$, which in…

General Relativity and Quantum Cosmology · Physics 2024-10-28 Petr Jizba , Gaetano Lambiase , Giuseppe Gaetano Luciano , Leonardo Mastrototaro

Taking into consideration of a fractal structure for the black hole horizon, Barrow argued that the area law of entropy get modified due to quantum-gravitational effects. Accordingly, the corrected entropy takes the form $S\sim…

General Relativity and Quantum Cosmology · Physics 2023-09-28 Amin Salehi

Recently, Barrow accounts for the quantum gravitational effects to the black hole surface. Thus the conventional area-entropy relation has modified, $S=(A/A_{0})^{1+\Delta/2},$ with an exponent $\Delta$, ranges $0\le\Delta\le1$, quantifies…

General Relativity and Quantum Cosmology · Physics 2023-02-06 Nandhida Krishnan. P , Titus K Mathew

We formulate Barrow holographic dark energy, by applying the usual holographic principle at a cosmological framework, but using the Barrow entropy instead of the standard Bekenstein-Hawking one. The former is an extended black-hole entropy…

General Relativity and Quantum Cosmology · Physics 2021-01-04 Emmanuel N. Saridakis

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 the effects that arise from the inclusion of Weylian boundary terms in the Einstein gravitational field equations in the Big Bang Nucleosynthesis (BBN) framework. With the help of the generalized Friedmann equations for a…

General Relativity and Quantum Cosmology · Physics 2026-04-28 Teodora M. Matei , Cristian Croitoru , Tiberiu Harko

Applying the modified Barrow entropy, inspired by the quantum fluctuation effects, to the cosmological background, and using thermodynamics-gravity conjuncture, the Friedmann equations get modified as well. In this paper, we explore the…

General Relativity and Quantum Cosmology · Physics 2024-12-18 M. Motaghi , A. Sheykhi , E. Ebrahimi

In conventional general relativity, the expansion rate H of a Robertson-Walker universe is related to the energy density by the Friedmann equation. Aside from the present day, the only epoch at which we can constrain the expansion history…

Astrophysics · Physics 2014-10-13 Sean M. Carroll , Manoj Kaplinghat

In the standard hot big bang model, the expansion of the early universe is given by the Friedmann equation with an energy density dominated by relativistic particles. Since in a variety of models this equation is altered, we introduce…

Astrophysics · Physics 2016-08-16 Eduard Massó , Francesc Rota
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