English

Particle creation in FRW with variable $q$, $G$ and $\Lambda$

General Relativity and Quantum Cosmology 2018-10-10 v2

Abstract

In this study, the mechanism of particle creation using varying gravitational and cosmological constants and deceleration parameter has been studied for Friedman-Robertson-Walker at high dimensions to explain early deceleration and present accelerating phases. In order to investigate the dynamics of two phases, we have considered two different ansatz for the scale factor of the form a(t)=tαeta(t)=\sqrt{t^{\alpha}e^{t}} and a(t)=sinh(kt)a(t)=\sqrt{\sin h(kt)} which are general form of power-law expansions. Firstly we modified dd-dimensional field equations depend on time introduce a general formulation of particle creation and entropy generation mechanisms. We investigate time dependence of the several cosmological constant and quantities such as particle creation ψ\psi and entropy SS, gravitational constant GG, cosmological term Λ\Lambda, energy density ρ\rho, deceleration parameter qq etc. It is shown that all constant and other quantities, except the cosmological constant GG and entropy SS, characteristically decrease with time for two scale factors in all dimensions. However, the cosmological constant GG and entropy SS increase with time. Additionally, it is shown that the cosmological constant Λ\Lambda is unexpectedly independent of particle creation mechanism.

Keywords

Cite

@article{arxiv.1807.00190,
  title  = {Particle creation in FRW with variable $q$, $G$ and $\Lambda$},
  author = {Ozgur Sevinc and Ekrem Aydiner},
  journal= {arXiv preprint arXiv:1807.00190},
  year   = {2018}
}

Comments

10 figures, several refs have been added

R2 v1 2026-06-23T02:46:57.546Z