The object of the present paper is to study 3-dimensional trans-Sasakian manifolds admitting Ricci solitons and gradient Ricci solitons. We prove that if (1,V, ?) is a Ricci soliton where V is collinear with the characteristic vector field ?, then V is a constant multiple of ? and the manifold is of constant scalar curvature provided ?, ? =constant. Next we prove that in a 3-dimensional trans-Sasakian manifold with constant scalar curvature if 1 is a gradient Ricci soliton, then the manifold is either a ?-Kenmotsu manifold or an Einstein manifold. As a consequence of this result we obtain several corollaries.

In this study we introduce a new tensor in a semi-Riemannian manifold, named the M*-projective curvature tensor which generalizes the m-projective curvature tensor. We start by deducing some fundamental geometric properties of the M*-projective curvature tensor. After that, we study pseudo M*-projective symmetric manifolds (PM?S)n. A non-trivial example has been used to show the existence of such a manifold. We introduce a series of interesting conclusions. We establish, among other things, that if the scalar curvature ? is non-zero, the associated 1-form is closed for a (PM?S)n with divM* = 0. We also deal with pseudo M*-projective symmetric spacetimes, M*-projectively flat perfect fluid spacetimes, and M*-projectively flat viscous fluid spacetimes. As a result, we establish some significant theorems.