Dual formulations of Polyakov loop lattice models

TL;DR

This paper develops dual representations for non-abelian lattice spin models with U(N) and SU(N) symmetry, enabling local formulations with positive weights even at non-zero chemical potential, applicable to QCD Polyakov loop models.

Contribution

It extends dual formulations to arbitrary Wilson coupling and multiple quark flavors, facilitating simulations of complex non-abelian lattice models.

Findings

Dual models are local and positive at finite chemical potential.

Extension to arbitrary Wilson coupling and multiple flavors achieved.

Potential for Monte Carlo and tensor network methods discussed.

Abstract

Dual representations are constructed for non-abelian lattice spin models with U(N) and SU(N) symmetry groups, for all N and in any dimension. These models are usually related to the effective models describing the interaction between Polyakov loops in the strong coupled QCD. The original spin degrees of freedom are explicitly integrated out and a dual theory appears to be a local theory for the dual integer-valued variables. The construction is performed for the partition function and for the most general correlation function. The latter include the two-point function corresponding to quark-anti-quark free energy and the N-point function related to the free energy of a baryon. We consider both pure gauge models and models with static fermion determinant for both the staggered and Wilson fermions with an arbitrary number of flavours. While the Boltzmann weights of such models are complex in the presence of non-zero chemical potential the dual Boltzmann weights appear to be strictly positive on admissible configurations. An essential part of this work with respect to previous studies is an extension of the dual representation to the case of 1) an arbitrary value of the temporal coupling constant in the Wilson action and 2) an arbitrary number of flavours of static quark determinants. The applications and extensions of the results are discussed in detail. In particular, we outline a possible approach to Monte-Carlo simulations of the dual theory, to the large N expansion and to the development of a tensor renormalization group.