19 citations · 49 across the 3 of their papers we have counts for
3 papers
math.DG2019★ 14 cited
Gray s decomposition on doubly warped product manifolds and applications
Hoda K. El-Sayed, Carlo Alberto Mantica, Sameh Shenawy +1
A. Gray presented an interesting invariant decomposition of the covariant derivative of the Ricci tensor. Manifolds whose Ricci tensor satisfies the defining pr…
math.DG2016★ 16 cited
On symmetries of generalized Robertson-Walker Space-times and applications
H. K. El-Sayied, S. Shenawy, N. Syied
The purpose of the present article is to study and characterize sev- eral types of symmetries of generalized Robertson-Walker space-times. Con- formal vector fields, curvature and…
math.DG2015★ 19 cited
Conformal vector fields on doubly warped product manifolds and applications
H. K. El-Sayied, Sameh Shenawy, Noha Syied
In this article, we present a complete study of two disjoint classes of conformal vector fields on doubly warped product manifolds as well as on doubly warped space-times. Then we…