Caustics for Spherical Waves
High Energy Physics - Theory
2017-03-16 v3 Cosmology and Nongalactic Astrophysics
General Relativity and Quantum Cosmology
Abstract
We study the development of caustics in shift-symmetric scalar field theories by focusing on simple waves with an -symmetry in an arbitrary number of space dimensions. We show that the pure Galileon, the DBI-Galileon, and the extreme-relativistic Galileon naturally emerge as the unique set of caustic-free theories, highlighting a link between the caustic-free condition for simple -waves and the existence of either a global Galilean symmetry or a global (extreme-)relativistic Galilean symmetry.
Cite
@article{arxiv.1611.05038,
title = {Caustics for Spherical Waves},
author = {Claudia de Rham and Hayato Motohashi},
journal= {arXiv preprint arXiv:1611.05038},
year = {2017}
}
Comments
25 pages. v2: References added and included discussion on extreme-relativistic case. v3: Matches published version in PRD, appendix expanded