English

The solution of the cosmological constant problem from the inhomogeneous equation of state - a hint from modified gravity?

General Relativity and Quantum Cosmology 2009-01-16 v2 Astrophysics High Energy Physics - Phenomenology High Energy Physics - Theory

Abstract

The cosmological constant problem is studied in a two component cosmological model. The universe contains a cosmological constant of an arbitrary size and sign and an additional component with an inhomogeneous equation of state. It is shown that, in a proper parameter regime, the expansion of the universe with a large absolute value of the cosmological constant may asymptotically tend to de Sitter space corresponding to a small effective positive cosmological constant. It is argued that such a behavior can be regarded as a solution of the cosmological constant problem in this model. The mechanism behind the relaxation of the cosmological constant is discussed. A connection with modified gravity theories is discussed and an example of a possible realization of the cosmological constant relaxation in f(R) modified gravity is described.

Keywords

Cite

@article{arxiv.0807.3692,
  title  = {The solution of the cosmological constant problem from the inhomogeneous equation of state - a hint from modified gravity?},
  author = {Hrvoje Stefancic},
  journal= {arXiv preprint arXiv:0807.3692},
  year   = {2009}
}

Comments

18 pages, 8 figures, version to appear in Phys. Lett. B