Can Kilic, Johns Hopkins University
on Astrophysical Constraints on Spontaneous Lorentz Violation

The discovery of dark energy as the major component of the universe has led many to consider the possibility that there may be something we are missing about gravity at large distances. The recent theory of ghost condensation has defied the lore that trying to modify GR at large distances is doomed from the start. As is usual in the case of gauged symmetries, spontaneous symmetry breaking offers a way to modify the low energy physics while maintaining the symmetry in the UV. In this work we use ghost condensation as the effective theory of spontaneous Lorentz violation and attempt to put bounds on its couplings to matter using astrophysical considerations.