Kink Collisions in Curved Field Space

TL;DR

This paper explores bubble universe collisions in curved field spaces, providing a geometric interpretation and extending the free passage approximation, supported by analytical and numerical analysis.

Contribution

It introduces a geometric framework for understanding bubble collisions in curved field spaces and generalizes the free passage approximation beyond flat space.

Findings

Geometric interpretation of collisions in curved field space

Extension of the free passage approximation to curved spaces

Numerical simulations validating analytical results

Abstract

We study bubble universe collisions in the ultrarelativistic limit with the new feature of allowing for nontrivial curvature in field space. We establish a simple geometrical interpretation of such collisions in terms of a double family of field profiles whose tangent vector fields stand in mutual parallel transport. This provides a generalization of the well-known flat field space limit of the free passage approximation. We investigate the limits of this approximation and illustrate our analytical results with a numerical simulations.