Quase sólitons de Ricci Imersos em variedades Semi-Riemannianas carregando campos de vetores conformes

Abstract

In this thesis we will consider Riemannian manifolds isometrically immersed in semiRiemannian manifolds with constant sectional curvature. By establishing a connection between concircular fields and conformal fields, as well as by assuming that our Riemannian manifolds are totally umbilical, we will determine a Ricci almost soliton structure on them. In addition, we will study a manifestation of the Tashiro’s Theorem in this context by means of which we will construct three new examples of gradient Ricci almost solitons.