Overview of large N QCD with chemical potential at weak and strong coupling

TL;DR

This paper compares the QCD phase diagram at large Nc and Nf in weak and strong coupling regimes, showing how observables can be related across these regimes through a simple variable transformation.

Contribution

It provides a unified analysis of the QCD phase diagram at large Nc and Nf in both weak and strong coupling limits, demonstrating their agreement at moderate temperatures and chemical potentials.

Findings

Weak and strong coupling matrix models agree at moderate temperatures and chemical potentials.

Observables in strongly-coupled theory can be derived from weakly-coupled theory via a variable transformation.

The phase diagram is characterized using Polyakov line and quark number calculations.

Abstract

In this note we summarize the results from a longer article on obtaining the QCD phase diagram as a function of the temperature and chemical potential at large Nc and large Nf in the weak and the strong coupling limits. The weak coupling phase diagram is obtained from the Polyakov line order parameter, and the quark number, calculated using 1-loop perturbation theory for QCD formulated on S^1 x S^3. The strong coupling phase diagram is obtained from the same observables calculated at leading order in the lattice strong coupling and hopping parameter expansions. We show that the matrix models in these two limits agree at temperatures and chemical potentials which are not too high, such that observables in the strongly-coupled theory can be obtained from the observables in the weakly-coupled theory, and vice versa, using a simple transformation of variables.