Dynamics in UV completions of k-essence

ABSTRACT:

In recent years there has been an increased interest in modelling the nonlinear dynamics in theories beyond general relativity. Recent work by different groups has provided a new pathways towards performing numerical relativity simulations in such theories.

In this talk, I summarize subset of these ideas and will illustrate them in the context of k-essence, a subset of Horndeski theory. In particular, I will present and example where different extensions (or UV completions) of the theory allow for continuing the evolution past the Cauchy breakdown of the original theory.