IX Black Hole Workshop

Guimarães 19-20 December 2016

Bulk viscous Bianchi type-I Chaplygin gas Cosmological Model in Lyra Geometry The main objective of the presented article is to study the Bianchi type-I space-time in presence of bulk viscosity and Chaplygin gas in the context of Lyra geometry (LG). Exact solutions of the field equations are obtained under the consideration of (i) scale factor of the form a(t) = − are positive constant and H is the mean Hubble parameter. In literature, most of the studies based under the consideration of bulk viscosity ξ as a simple power function of energy density or constant or ξ ∝ θ(expansion scalar). Thus we took ξ as a linear combination of constant & expansion scalar as in (ii) and checked the results resembles with the constant and variable bulk viscosities. It is found that the considered form of bulk viscosity has the similar qualitative behavior as that of constant and variable bulk viscosities. The considered form of scale factor, leads to a time dependent deceleration parameter, which generates an accelerating Universe. The physical aspects and stability of the model are discussed with graphical representations. 1 2, t > 1 and (ii) bulk viscosity of the form ξ = ξ0 + ξ1H, where ξ0 & ξ1 t + t.