English

A Matter with an effective EoS interacting with a tachynic field in an accelerating Universe

General Physics 2013-08-06 v3 General Relativity and Quantum Cosmology

Abstract

We consider a fluid described by a parameterized EoS of the general form P=(γ1)ρ+p0+ωHH+ωH2H2+ωdHH˙P=(\gamma-1)\rho+p_{0}+\omega_{H}H+\omega_{H2}H^{2}+\omega_{dH}\dot{H} \cite{Ren}, where p0p_{0}, ωH\omega_{H}, ωH2\omega_{H2} and ωdH\omega_{dH} are free parameters of the model, interacting with a Tachyonic field with a relativistic Lagrangian LTF=V(ϕ)1iϕiϕL_{TF}=-V(\phi)\sqrt{1-\partial_{i}\phi\partial^{i}\phi}. The acceleration of the Universe described by a scale factor a(t)=tn,(n>1)a(t)=t^{n}, (n>1). Under consideration of different forms of interaction the field ϕ\phi and the potential V(ϕ)V(\phi) are recovered and graphical analysis performed. For illustration purposes we fixed values of parameters of the models to provide V0V \rightarrow 0 for later stages of evolution, when tt \rightarrow \infty.

Keywords

Cite

@article{arxiv.1301.0005,
  title  = {A Matter with an effective EoS interacting with a tachynic field in an accelerating Universe},
  author = {Martiros Khurshudyan},
  journal= {arXiv preprint arXiv:1301.0005},
  year   = {2013}
}

Comments

14 pages, 7 figures, typos corrected and references added. arXiv admin note: substantial text overlap with arXiv:1307.7859, and text overlap with arXiv:1210.0001 by other authors