Izvorni znanstveni članak
Nonsingular cosmological models with a variable cosmological term Λ
Anirudh Pradhan
; Department of Mathematics, Hindu Post-graduate College, Zamania-232 331, Ghazipur, India
Kashika Srivastava
; Department of Mathematics, Hindu Post-graduate College, Zamania-232 331, Ghazipur, India
Amrit Lal Ahuja
; Inter-University Centre for Astronomy and Astrophysics, Ganeshkhind, Pune-411 007, India
Sažetak
Exact solutions of the Einstein's field equations describing a spherically symmetric cosmological model without a big bang or any other kind of singularity recently obtained by Dadhich and Patel (2000) are revisited. The matter content of the model is a shear-free perfect fluid with isotropic pressure and a radial heat flux. Three different exact solutions are obtained both for perfect fluid and fluid with bulk viscosity. It turns out that the cosmological term Λ(t) is a decreasing function of time, which is consistent with recent observations of type Ia supernovae.
Ključne riječi
non-singular models; cosmology; variable cosmological constant; causality principle
Hrčak ID:
304467
URI
Datum izdavanja:
1.7.2007.
Posjeta: 408 *