English

Bouncing solutions from generalized EoS

General Relativity and Quantum Cosmology 2018-01-17 v1

Abstract

We present an exact analytical bouncing solution for a closed universe filled with only one exotic fluid with negative pressure, obeying a Generalized Equations of State (GEoS) of the form P(ρ)=Aρ+BρλP(\rho)=A\rho+B\rho^{\lambda}, where AA, BB and λ\lambda are constants. In our solution A=1/3A=-1/3 and λ=1/2\lambda=1/2 and B<0B<0 is kept as a free parameter. For particular values of the initial conditions, we obtain that our solution obeys Null Energy Condition (NEC), which allows us to reinterpret the matter source as that of a real scalar field, ϕ\phi, with a positive kinetic energy and a potential V(ϕ)V(\phi). We compute numerically the scalar field as a function of time as well as its potential V(ϕ)V(\phi), and find an analytical function for the potential that fits very accurately with the numerical results obtained. The shape of this potential can be well described by a Gaussian-type of function, and hence, there is no spontaneous symmetry minimum of V(ϕ)V(\phi). We further show that the bouncing scenario is structurally stable under small variations of the parameter AA, such that a family of bouncing solutions can be find numerically, in a small vicinity of the value A=1/3A=-1/3.

Keywords

Cite

@article{arxiv.1701.03438,
  title  = {Bouncing solutions from generalized EoS},
  author = {F. Contreras and N. Cruz and G. Palma},
  journal= {arXiv preprint arXiv:1701.03438},
  year   = {2018}
}

Comments

12 pages, 12 figures

R2 v1 2026-06-22T17:48:55.697Z