# Absence of Physical Walls in Hot Gauge Theories

## TL;DR

This paper demonstrates that in high-temperature $Z(2)$ lattice gauge theories, physical walls do not exist in the deconfined phase, and the interface phenomena are explained through physical variables and partition functions.

## Contribution

It clarifies the non-existence of physical walls in the deconfined phase and interprets interface energies using physical variables and partition functions.

## Key findings

- No physical walls in the high-temperature phase.
- Interface energy relates to flux differences in partition functions.
- Matter presence lowers free energy without creating metastable states.

## Abstract

This paper shows that there are no {\em physical} walls in the deconfined, high-temperature phase of $Z(2)$ lattice gauge theory. In a Hamiltonian formulation, the interface in the Wilson lines is not physical. The line interface and its energy are interpreted in terms of physical variables. They are associated with a difference between two partition functions. One includes only the configurations with even flux across the interface. The other is restricted to odd flux. Also, with matter present, there is no physical metastable state. However, the free energy is lowered by the matter. This effect is described in terms of physical variables.