Black holes and vacua in string theory: A non-supersymmetric study

During the past few decades, an important part of the understanding of gravity in the context of string theory has relied on gravitational configurations that enjoy supersymmetry. Despite the knowledge retrieved under supersymmetry, we still do not fully understand the microscopics of realistic gravitational configurations. In this thesis, we study two gravitational solutions with broken supersymmetry: non-extremal black holes, and non-supersymmetric metastable states in string theory