Bubble dynamics in a QCD-like phase diagram

TL;DR

This paper uses holography to simulate bubble dynamics in a QCD-like phase diagram, providing insights into phase transitions in neutron star mergers and their gravitational wave signatures.

Contribution

It presents the first microscopic holographic simulation of bubble dynamics in a QCD-like theory, estimating wall velocities and analyzing gravitational wave implications.

Findings

Wall velocity in metastable regions determined

Comparison with theoretical estimates performed

Implications for gravitational wave signals discussed

Abstract

A line of first-order phase transitions is conjectured in the phase diagram of Quantum Chromodynamics at non-zero baryon density. If this is the case, numerical simulations of neutron star mergers suggest that various regions of the stars may cross this line multiple times. This results in the nucleation of bubbles of the preferred phase, which subsequently expand and collide. The resulting gravitational wave spectrum is highly sensitively to the velocity of the bubble walls. We use holography to perform the first microscopic simulation of bubble dynamics in a theory that qualitatively mirrors the expected phase diagram of Quantum Chromodynamics. We determine the wall velocity in the metastable regions and we compare it to theoretical estimates. We discuss implications for gravitational wave production.