Pseudo-gauge invariant non-equilibrium density operator

TL;DR

This paper derives a pseudo-gauge invariant local thermodynamic equilibrium density operator, reducing ambiguity in observable predictions and applicable to high-energy nuclear collision systems.

Contribution

It introduces a pseudo-gauge invariant form of the local equilibrium density operator, addressing gauge ambiguities in quantum states.

Findings

The operator is invariant under pseudo-gauge transformations.

It effectively describes systems reaching local equilibrium in high-energy nuclear collisions.

Reduces ambiguity in observable predictions from local equilibrium states.

Abstract

We obtain a form of the local thermodynamic equilibrium density operator which is invariant under pseudo-gauge transformations of the stress-energy and the spin tensors. This operator is an excellent candidate to describe the dynamics of a system which is assumed to achieve local equilibrium from a pseudo-gauge invariant quantum state, a situation which is believed to occur, for instance, in nuclear collisions at very high energy. As a consequence of pseudo-gauge invariance, the ambiguity affecting the predictions of mean values of observables from a local equilibrium state can be removed.