Collisions of false vacuum bubbles in cylindrical symmetry

TL;DR

This paper investigates the nonlinear dynamics of colliding cylindrical false vacuum bubbles in general relativity, revealing complex interactions, potential singularities, and insights into the scalar field landscape without horizon formation.

Contribution

It provides the first detailed numerical analysis of cylindrical bubble collisions in GR, exploring the full nonlinear evolution and resulting spacetime structures.

Findings

Collision creates a strongly interacting, inhomogeneous region.

No horizons form; scalar curvature invariants diverge.

Potential for complex spacetime regions beyond simple horizon models.

Abstract

We explore the collision of two cylindrical bubbles in classical general relativity with a scalar field stress-energy tensor. Inside each bubble the field rests at a local minimum of the potential with non-negative energy density. Outside the field rests at zero potential, the global minimum. The calculation resolves the connection from the inner de-Sitter region to the asymptotically flat Minkowski spacetime. We choose initial conditions such that the two bubbles collide and study the full nonlinear evolution by means of a two-dimensional numerical simulation of Einstein's equations. The collision generates a strongly interacting region with spatially varying fields and potentials. These circumstances promote dynamical exploration of the potential's landscape. No horizon is present and the scalar curvature invariants eventually diverge. We speculate that Schwarzschild-like horizons will encompass only part of the complicated, interesting regions of spacetime in the analogous case of colliding spherical bubbles.