Towards a Solution of the Cosmological Domain Walls Problem

TL;DR

This paper investigates how biasing in cosmological phase transitions leads to unstable, finite, bag-like domain wall networks that decay exponentially, influenced by potential parameters and background fluctuations.

Contribution

It introduces a new type of unstable domain wall network arising from biased phase transitions, challenging previous assumptions about their stability.

Findings

Biased networks are compact and exhibit exponential decay.

Background fluctuations destabilize the networks even with symmetric initial conditions.

Potential parameters affect the lifetime of the domain wall networks.

Abstract

We show that all kinds of biasing of cosmological phase transitions produce qualitatively new type of domain wall networks. The biased networks consist of compact, finite size, bag-like wall structures and exhibit a generic instability. The surface of biased networks disappears exponentially fast after a limited period of scaling. We argue that fluctuations of the background make the network unstable even in the case of the ``symmetric on the average'' initial distribution. We observe that the variation in parameters of the potential, like its hight, can influence the lifetime of the wall network, contrary to the standard beliefs.