Static spaces (with perfect fluids) appeared in a natural way both in physics (cf. Hawking and
Ellis, 1975) and mathematics (cf. A. Fischer and J. Marsden, Duke Math. J. 42 (3)(1975), 519 …

The goal of this paper is to investigate almost conformal Ricci solitons on extended
Robertson–Walker and standard static space-times in terms of conformal vector fields …

A torqued vector field ξ is a torse-forming vector field on a Riemannian manifold that is
orthogonal to the dual vector field of the 1-form in the definition of torse-forming vector field …

In this paper, first we study the harmonicity of the functions and forms on the twisted
products, and then we determine its sectional curvature. We explore some characteristics of …

We continue studying the σ-Ricci vector field u on a Riemannian manifold (N m, g), which is
not necessarily closed. A Riemannian manifold with Ricci operator T, a Coddazi-type tensor …

In the present article, we extend the notion of vacuum static equations on almost coKähler
manifolds and rename them as nearly vacuum static equations. It is shown that if an η …