Bubble, Bubble, Flow and Hubble: Large Scale Galaxy Flow from Cosmological Bubble Collisions

TL;DR

This paper investigates how cosmological bubble collisions influence large-scale galaxy flows, revealing that such collisions can induce measurable bulk galaxy motions depending on initial conditions and inflation parameters.

Contribution

It provides a quantitative analysis of galaxy bulk flows caused by bubble collisions within a controlled approximation framework, highlighting potential observable effects.

Findings

Bubble collisions induce coherent galaxy bulk flows.

Effects depend on initial collision conditions and inflation amount.

Measurable flows can occur even with sufficient inflation to solve flatness and horizon problems.

Abstract

We study large scale structure in the cosmology of Coleman-de Luccia bubble collisions. Within a set of controlled approximations we calculate the effects on galaxy motion seen from inside a bubble which has undergone such a collision. We find that generically bubble collisions lead to a coherent bulk flow of galaxies on some part of our sky, the details of which depend on the initial conditions of the collision and redshift to the galaxy in question. With other parameters held fixed the effects weaken as the amount of inflation inside our bubble grows, but can produce measurable flows past the number of efolds required to solve the flatness and horizon problems.