English

Constraining bouncing cosmology caused by Casimir effect

Astrophysics 2009-11-13 v3

Abstract

In our paper we constrain Friedman Robertson Walker (FRW) model with ``radiation-like'' contribution to the Friedmann equation against the astronomical data. We analyze the observational limitations on a (1+z)4(1+z)^4 term from SNIa data, FRIIb radio galaxy (RG) data, baryon oscillation peak and CMBR observations. We argue that it is not possible to determine the energy densities of individual components scaling like radiation from a kinematic astronomical test. The bounds for density parameter for total radiation-like term can be obtained. We find different interpretations of the presence of scaling like radiation term: FRW universe filled with a massless scalar field in a quantum regime (Casimir effect), Friedmann-Robertson-Walker (FRW) model in a semi-classical approximation of loop quantum gravity, FRW model in the Randall Sundrum scenario with dark radiation or cosmological model with global rotation. In this paper we mainly concentrate on Casimir effect arising from quantum effects of the scalar field. This contribution can describe decaying part of cosmological constant. We discuss the back reaction of gravity on Casimir-type force which is a manifestation of the vacuum fluctuations of the quantum scalar field at low temperature. It is shown that while the Casimir energy gives rise to accelerating Universe, the cosmological constant term is still required. We argue that a small negative contribution of a radiation-like term can reconcile the tension between the observed primordial 4He{}^4He and DD abundance. Moreover the presence of such contribution can also remove the disagreement between Hubble parameter H0H_0 values obtained from both SNIa and Wilkinson Microwave Anisotropy Probe (WMAP) satellite data.

Keywords

Cite

@article{arxiv.astro-ph/0702237,
  title  = {Constraining bouncing cosmology caused by Casimir effect},
  author = {Wlodzimierz Godlowski and Marek Szydlowski and Zong-Hong Zhu},
  journal= {arXiv preprint arXiv:astro-ph/0702237},
  year   = {2009}
}

Comments

11 pages, 2 figures Gravitation & Cosmology accepted