Ricci solitons (RS) have an extensive background in modern physics and are extensively
used in cosmology and general relativity. The focus of this work is to investigate Ricci almost …

In the context of paracontact geometry, $\eta $-Ricci solitons are considered on manifolds
satisfying certain curvature conditions: $(\xi,\cdot) _ {R}\cdot S= 0$, $(\xi,\cdot) _ {S}\cdot R …

We prove that if an η-Einstein para-Kenmotsu manifold admits a conformal η-Ricci soliton
then it is Einstein. Next, we proved that a para-Kenmotsu metric as a conformal η-Ricci …

We consider 𝜂-Ricci solitons on Lorentzian para-Sasakian manifolds satisfying certain
curvature conditions: 𝑅 (𝜉, 𝑋)· 𝑆= 0 and 𝑆· 𝑅 (𝜉, 𝑋)= 0. We prove that on a Lorentzian para …

The Eisenhart problem of finding parallel tensors is solved for the symmetric case in the
regular $ f $-Kenmotsu framework. On this way, the Olszack-Rosca example of Einstein …

In this paper we study Ricci solitons in Kenmotsu manifolds. We consider quasi conformal,
conharmonic and projective curvature tensors in a Kenmotsu manifold admitting Ricci …

We study Ricci solitons in Lorentzian α-Sasakian manifolds. It is shown that a symmetric
parallel second order covariant tensor in a Lorentzian α-Sasakian manifold is a constant …

In 1923, Eisenhart [9] proved that if a positive definite Riemannian manifold (M, g) admits a
second order parallel symmetric covariant tensor other than a constant multiple of the metric …

The aim of this paper is to find some important classes of Einstein manifolds using conformal
η-Ricci solitons and conformal η-Ricci almost solitons. We prove that a Kenmotsu metric as …

The Eisenhart problem of finding parallel tensors treated already in the framework of quasi-
constant curvature manifolds in\cite {x: j} is reconsidered for the symmetric case and the …