On pseudo Q-symmetric spacetimes
In previous papers, the notions of pseudo-symmetric manifolds \((PS)_n\), pseudo \(Q\)-symmetric manifolds \((PQS)_n\) and pseudo concircular manifolds \((P\tilde CS)_n\) were introduced. In the present paper, pseudo \(Q\)-symmetric spacetimes \((PQS)_4\) are studied and it is proved that they are quasi-Einstein. Further, properties of perfect fluid \((PQS)_4\) spacetimes are studied and it is shown that \((PQS)_4\) spacetimes with cyclic parallel Ricci tensor is Einstein. Example of \((PQS)_4\) spacetimes is given.
scientific article; zbMATH DE number 7138545
scientific article