Theoretical Models for Astrophysical Objects and the Newman-Janis Algorithm

Abstract

We consider the problem of finding exact solutions of Einstein equations describing gravitational fields generated by isolated sources in order to provide theoretical models for astrophysical objects. To this aim, the Newman-Janis Algorithm is described along with the main results obtained through it and some ambiguities arising in dealing with the Newman-Janis Algorithm are reviewed. Many issues related to the introduction of a cosmological constant term are also pointed out and some detailed examples are discussed.