Cool quark matter

TL;DR

This paper extends the perturbative Equation of State for cold quark matter to nonzero temperatures, crucial for modeling neutron star mergers and core collapse, using a novel framework that combines effective theories and resummation techniques.

Contribution

It introduces a new method for calculating the quark matter Equation of State at finite temperature with high accuracy, incorporating soft mode resummation and effective theory approaches.

Findings

Accurate to order g^5 in gauge coupling.

Applicable to small nonzero temperatures and out of beta equilibrium.

Provides a framework for astrophysical applications like neutron star mergers.

Abstract

We generalize the state-of-the-art perturbative Equation of State of cold quark matter to nonzero temperatures, needed in the description of neutron star mergers and core collapse processes. The new result is accurate to order g^5 in the gauge coupling, and is based on a novel framework for dealing with the infrared sensitive soft field modes of the theory. The zero Matsubara mode sector is treated using a dimensionally reduced effective theory, while the soft non-zero modes are resummed using the Hard Thermal Loop approximation. This combination of known effective descriptions offers unprecedented access to small but nonzero temperatures, both in and out of beta equilibrium.