Axion-Dilaton Domain Walls and Fake Supergravity

TL;DR

This paper employs dynamical systems techniques to analyze axion-dilaton domain walls, revealing new solutions, bifurcations, and insights into fake supergravity, especially regarding multi-valued superpotentials and consistent truncations.

Contribution

It provides a comprehensive global analysis of domain walls in axion-dilaton models, introduces a new exact solution, and proposes a generalized fake supergravity formalism.

Findings

New exact domain-wall solution with non-constant axion

Multi-valued superpotentials branch at non-stationary points

Inconsistencies in single-scalar truncations identified

Abstract

Dynamical systems methods are used to investigate domain-wall solutions of a two-parameter family of models in which gravity is coupled to an axion, and to a dilaton with an exponential potential of either sign. A complete global analysis is presented for (i) constant axion and (ii) flat walls, including a study of bifurcations and a new exact domain-wall solution with non-constant axion. We reconsider `fake supergravity' issues in light of these results. We show, by example, how domain walls determine multi-valued superpotentials that branch at stationary points that are not stationary points of the potential, and we apply this result to potentials with anti-de Sitter vacua. We also show by example that `adapted' truncation to a single-scalar model is sometimes inconsistent, and we propose a `generalized' fake supergravity formalism that applies in some such cases.