The density of states approach at finite chemical potential: a numerical study of the Bose gas

TL;DR

This paper applies a new density of states algorithm to the relativistic Bose gas at finite chemical potential, effectively addressing the sign problem and simplifying complex integrals in quantum field theories.

Contribution

It demonstrates the practical application of a novel density of states method to a quantum field theory with finite density, showcasing its potential to mitigate the sign problem.

Findings

Successful reduction of integral complexity in the Bose gas model

Potential to extend the method to other theories with sign problems

Improved numerical stability in finite density simulations

Abstract

Recently, a novel algorithm for computing the density of states in statistical systems and quantum field theories has been proposed. The same method can be applied to theories at finite density affected by the notorious sign problem, reducing a high-dimensional oscillating integral to a more tractable one-dimensional one. As an example we applied the method to the relativistic Bose gas.