Localized Gravity and Higher Curvature Terms

TL;DR

This paper investigates how higher curvature Gauss-Bonnet terms affect gravity localization on domain walls, emphasizing conditions for non-singular solutions and the impact on unitarity and energy conditions.

Contribution

It analyzes the influence of Gauss-Bonnet terms on gravity localization, establishing conditions for non-singular domain walls and constraints on scalar potentials for unitarity.

Findings

Gauss-Bonnet term prevents flat solutions with localized gravity that violate weak energy condition.

Infinite tension flat domain walls violate positivity in presence of Gauss-Bonnet term.

Scalar potential must be bounded below for unitarity in flat solutions.

Abstract

We consider localization of gravity in smooth domain wall solutions of gravity coupled to a scalar field with a generic potential in the presence of the Gauss-Bonnet term. We discuss conditions on the scalar potential such that domain wall solutions are non-singular. We point out that the presence of the Gauss-Bonnet term does not allow flat solutions with localized gravity that violate the weak energy condition. We also point out that in the presence of the Gauss-Bonnet term infinite tension flat domain walls violate positivity. In fact, for flat solutions unitarity requires that on the solution the scalar potential be bounded below.