pith. sign in

arxiv: 1209.3768 · v1 · pith:WXTKZN4Pnew · submitted 2012-09-17 · ✦ hep-th · gr-qc

Subluminal Galilean Genesis

classification ✦ hep-th gr-qc
keywords cosmologicalgalileanconformalfluctuationsgenesisgroupinvariancemodel
0
0 comments X
read the original abstract

We put forward an improved version of the Galilean Genesis model that addresses the problem of superluminality. We demote the full conformal group to Poincare symmetry plus dilations, supplemented with approximate galilean shift invariance in the UV and at small field values. In this way fluctuations around the NEC-violating cosmological background are made substantially subluminal, and superluminality cannot be reached by any small change of the solution, in contrast with the original model. Dilation invariance still protects the scale-invariance of correlation functions of a massless test scalar - which is the source of the observed cosmological fluctuations - but the explicit breaking of the conformal group can be potentially observed in higher-order correlators. We also highlight a subtlety in matching the NEC-violating phase with the standard cosmological evolution, and discuss the possible couplings of the Galileon to gravity.

This paper has not been read by Pith yet.

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.