A cyclic cosmological model based on the f({\rho}) modified theory of gravity
Abstract
We consider FLRW cosmological models for perfect fluid (with rho as the energy density) in the frame work of the f(rho) modified theory of gravity [V. N. Tunyak, Russ. Phys. J. 21, 1221 (1978); J. R. Ray, L. L. Smalley, Phys. Rev. D. 26, 2615 (1982) ]. This theory, with total Lagrangian R-f(rho), can be considered as a cousin of the F(R) theory of gravity with total Lagrangian F(R)-rho. We can pick proper function forms f(rho) to achieve, as the F(R) theory does, the following 4 specific goals, (1) producing a non-singular cosmological model (Ricci scalar and Ricci tensor curvature are bounded); (2) explaining the cosmic early inflation and late acceleration in a unified fashion; (3) passing the solar system tests; (4) unifying the dark matter with dark energy. In addition we also achieve goal number (5): unify the regular matter/energy with dark matter/energy in a seamless fashion. The mathematics is simplified because in the f(rho) theory the leading terms in Einstein's equations are linear in second order derivative of metric wrt coordinates but in the F(R) theory the leading terms are linear in fourth order derivative of metric wrt coordinates.
Cite
@article{arxiv.1106.0341,
title = {A cyclic cosmological model based on the f({\rho}) modified theory of gravity},
author = {Yaoming Shi},
journal= {arXiv preprint arXiv:1106.0341},
year = {2011}
}
Comments
27 pages, 2 figures, 3 tables. Several references and some comments added in version 2. Appendix A updated in version 2. Appendix A moved to appendix B in version 3. A new appendix A for the derivation of the energy-momentum tensor (2.2)-(2.3) in f(rho) theory is added in version 3