English
Related papers

Related papers: Big Bang Nucleosynthesis constraints on Barrow ent…

200 papers

Using thermodynamics-gravity conjecture, we present the formal derivation of the modified Friedmann equations inspired by the Barrow entropy, $S\sim A ^{1+\delta/2}$, where $0\leq\delta\leq 1$ is the Barrow exponent and $A$ is the horizon…

General Relativity and Quantum Cosmology · Physics 2025-12-04 Ahmad Sheykhi , Ava Shahbazi Sooraki

We confront $f(T,T_G)$ gravity, with Big Bang Nucleosynthesis (BBN) requirements. The former is obtained using both the torsion scalar, as well as the teleparallel equivalent of the Gauss-Bonnet term, in the Lagrangian, resulting to…

General Relativity and Quantum Cosmology · Physics 2022-09-20 Petros Asimakis , Emmanuel N. Saridakis , Spyros Basilakos , Kuralay Yesmakhanova

We use Big Bang Nucleosynthesis (BBN) data in order to impose constraints on higher-order modified gravity, and in particular on: (i) $f(G)$ Gauss-Bonnet gravity, and $f(P)$ cubic gravities, arising respectively through the use of the…

General Relativity and Quantum Cosmology · Physics 2022-04-11 Petros Asimakis , Spyros Basilakos , Nick E. Mavromatos , Emmanuel N. Saridakis

We use data from M87* central black hole shadow, as well as from the S2 star observations, in order to extract constraints on Barrow entropy. The latter is a modified entropy arising from quantum-gravitational effects on the black hole…

General Relativity and Quantum Cosmology · Physics 2022-02-08 Kimet Jusufi , Mustapha Azreg-Aïnou , Mubasher Jamil , Emmanuel N. Saridakis

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

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

Big Bang Nucleosynthesis (BBN) is studied within the framework of a two-parameter family of tensor-scalar theories of gravitation, with nonlinear scalar-matter coupling function a(phi). We run a BBN code modified by tensor-scalar gravity,…

Astrophysics · Physics 2009-10-30 Thibault Damour , Bernard Pichon

In this work, we investigate the viability of some cosmological models derived from generalized horizon entropies, using Big Bang Nucleosynthesis (BBN) constraints. By analyzing the deviations in the expansion rate, we derive bounds on the…

General Relativity and Quantum Cosmology · Physics 2026-04-22 Kajal Phukan , Rajdeep Mazumdar , Kalyan Malakar , Kalyan Bhuyan

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

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

Big Bang Nucleosynthesis provides us with an observational insight into the very early Universe. Since this mechanism of light element synthesis comes out of the standard model of particle cosmology which follows directly from General…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-14 Sai Swagat Mishra , Ameya Kolhatkar , P. K. Sahoo

The $f(Q)$ theories of modified gravity arise from the consideration of non-metricity as the basic geometric quantity, and have been proven to be very efficient in describing the late-time Universe. We use the Big Bang Nucleosynthesis (BBN)…

General Relativity and Quantum Cosmology · Physics 2023-02-08 Fotios K. Anagnostopoulos , Viktor Gakis , Emmanuel N. Saridakis , Spyros Basilakos

We present new Big Bang Nucleosynthesis (BBN) limits on the cosmic expansion rate or relativistic energy density, quantified via the number $N_\nu$ of equivalent neutrino species. We use the latest light element observations, neutron mean…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-01 Tsung-Han Yeh , Jessie Shelton , Keith A. Olive , Brian D. Fields

Big Bang Nucleosynthesis (BBN) is a strong probe for constraining new physics including gravitation. $f(R)$ gravity theory is an interesting alternative to general relativity which introduces additional degrees of freedom known as…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-04 Abhijit Talukdar , Sanjeev Kalita , Nirmali Das , Nandita Lahkar

A cosmological model with a time-varying mass of electrons seems a promising solution for the so-called Hubble tension. We examine the big bang nucleosynthesis (BBN) constraints on the time-varying electron mass model, because a larger…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-01 Osamu Seto , Yo Toda

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 use observational data from Supernovae (SNIa) Pantheon sample, as well as from direct measurements of the Hubble parameter from the cosmic chronometers (CC) sample, in order to extract constraints on the scenario of Barrow holographic…

General Relativity and Quantum Cosmology · Physics 2020-06-25 Fotios K. Anagnostopoulos , Spyros Basilakos , Emmanuel N. Saridakis

In this work, we investigate Big Bang Nucleosynthesis (BBN) within the framework of $f(T,{L}_m)$ gravity, where the gravitational Lagrangian is generalized as a function of the torsion scalar $T$ and the matter Lagrangian ${L}_m$. We…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-25 Daniel F. P. Cruz , David S. Pereira , Francisco S. N. Lobo , José P. Mimoso

Big Bang Nucleosynthesis (BBN), as one of the earliest processes in the universe accessible to direct observation, offers a powerful and independent probe of the cosmic expansion history. With recent advances in both theory and observation,…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-25 Christopher Cook , Joel Meyers

We examine the constraints imposed by the requirement of successful big bang nucleosynthesis on models with one large extra dimension and a single bulk neutrino. We solve the Boltzman kinetic equations for the thermal distribution of bulk…

High Energy Physics - Phenomenology · Physics 2009-11-07 H. S. Goh , R. N. Mohapatra
‹ Prev 1 2 3 10 Next ›