Paredes de domínio curvas em gravitação quase-topológica

Abstract

Extensions of General Relativity, with higher order terms in the curvature, have been used in order to better understand phenomena in scales where quantum effects become important. However, such extensions may produce undesirable effects, as the appearing of “ ghosts” and also equations of order greater than two, which complicates the Cauchy problem. In this dissertation we study a class of theories, known as Quasi Topological Gravity (QTG) , where these effects , by construction, are circumvented. In particular, we construct exact domain wall type solutions for QTG coupled to a scalar field subject to som potential for the case in which the vacua of the theory are Anti de Sitter (AdS) spaces. Our analysis is performed for an arbitrary dimension d of the space-time making use of an ansatz which considers the slicing of this space in (d-1) hypersurfaces with negative or positive curvature.