# L.R.S. Bianchi type II Stiff Fluid Cosmological model with Decaying ? in General Relativity

Author Affiliations

^{1}Govt. Engineering College, Rewa–486 001, MP, INDIA

*Res. J. Recent Sci.,* **Volume 1, Issue (10),** Pages 82-84, October,2 **(2012)**

## Abstract

Einstein’s field equations with variable cosmological constants are considered in the presence of stiff fluid for LRS Bianchi type-II universe. To get the deterministic model of the universe, we have assumed a condition A=B. It is shown that the vacuum energy density is positive and proportional to 1/t^{2}. The model represent accelerating, shearing and non-rotating universe. The physical and geometrical behavior of these models are also discussed.

## References

- Weinberg S., The cosmological constant problem, Rev. Mod. Phys,61, 1 (1989)
- Sahni V. and Starobinsky A.A., The Case for a Positive Cosmological -Term, Int. J. Mod. Phys., D9, 373 (2000)
- Peebles P.J.E. and Ratra B., The cosmological constant and dark energy, Rev. Mod. Phys,75, 559 (2003)
- Gasperini M., Decreasing vacuum temperature: A thermal approach to the cosmological constant problem, Phys. Lett. B,194, 347 (1987)
- Gasperini M.A., Thermal interpretation of the cosmological constant, Class. Quant. Grav,5, 521 (1988)
- Berman M.S., Static universe in a modified brans-dicke cosmology, Int. J. Theor. Phys,29, 567 (1990)
- Berman M.S., Brans-Dicke cosmology with time-dependent cosmological term, Int. J. Theor. Phys,29, 1419 (1990)
- Berman M.S. and Som M.M., Brans-Dicke models with time-dependent cosmological term, Int. J. Theor. Phys,29, 1411 (1990)
- Ozer M. and Taha M.O., A model of the universe free of cosmological problems, Nucl. Phys. B, 287, 776 (1987)
- Pradhan A. and Yadav V.K., Bulk Viscous Anisotropic Cosmological Models with Variable G and , Int. J. Mod Phys. D,11, 893 (2002)
- Zel’dovich Ya B., A hypothesis, unifying the structure and the entropy of the Universe, Mon. Not. R. Astron. Soc.,160, 1 (1972)
- Barrow J.D., The deflationary universe: An instability of the de Sitter universe, Phys. Lett. B,180, 335 (1986)
- Wesson P.S., An exact solution to Einstein's equations with a stiff equation of state, J. Math. Phys.,19, 2283 (1978)
- G¨otz G., A plane-symmetric solution of Einstein's equations with perfect fluidand an equation of state p = , Gen. Relativ. Gravit.,20, 23 (1988)
- Al-Rawaf A.S., A Cosmological Model with a Generalized Cosmological Constant, Mod. Phys. Lett. A, 13, 429 (1998)
- Overduin J.M. and Cooperstock F.I., Evolution of the scale factor with a variable cosmological term, Phys. Rev. D, 58, 043506, (1998)