The QCD equation of state from the lattice

TL;DR

This paper reviews recent advances in calculating the QCD equation of state at finite temperature and density using lattice QCD, crucial for understanding phenomena in particle physics, cosmology, and astrophysics.

Contribution

It provides a comprehensive summary of the current state of lattice QCD calculations of the QCD equation of state, focusing on discretisation schemes and systematic error control.

Findings

Lattice QCD simulations at the physical point are now feasible.

Finite temperature results near the continuum limit are available.

Systematic errors in lattice QCD calculations are being effectively controlled.

Abstract

The equation of state of QCD at finite temperatures and baryon densities has a wide range of applications in many fields of modern particle and nuclear physics. It is the main ingredient to describe the dynamics of experimental heavy ion collisions, the expansion of the early universe in the standard model era and the interior of compact stars. On most scales of interest, QCD is strongly coupled and not amenable to perturbative investigations. Over the last decade, first principles calculations using lattice QCD have reached maturity, in the sense that for particular discretisation schemes simulations at the physical point have become possible, finite temperature results near the continuum limit are available and systematic errors begin to be controlled. This review summarises the current theoretical and numerical state of the art based on staggered and Wilson fermions.