Bianchi type-II, VIII and IX cosmological models in a modified theory of gravity with variable Λ

Spatially homogeneous Bianchi type- II , VIII and IX perfect fluid cosmological models in f ( R , T ) modified theory of gravity have been investigated for a special choice of f ( R , T ) = f 1 ( R ) + f 2 ( T ) with f 1 ( R ) = λ 1 R and f 2 ( T ) = λ 2 T . This special choice leads to a cosmological constant Λ , which depends on stress energy tensor of matter source. To get the deterministic model of Universe, we assume that the expansion scalar ( θ ) in the model is proportional to shear scalar ( σ ). This condition leads to relation between metric potentials, which yields a time dependent deceleration parameter. Various physical and geometrical features of the models are also discussed.