Causality and the Skyrme Model

TL;DR

This paper demonstrates that the SU(2) Skyrme model and the Born-Infeld-Skyrme model inherently satisfy energy conditions that prevent violations of Einstein causality, despite potential hyperbolicity issues.

Contribution

It establishes that these models cannot violate Einstein causality due to their energy-momentum tensor properties, even if hyperbolicity breaks down.

Findings

SU(2) Skyrme model satisfies dominant and strong energy conditions.

Born-Infeld-Skyrme model also satisfies these energy conditions.

Models cannot violate Einstein causality despite hyperbolicity issues.

Abstract

It is shown that despite the possibility of a breakdown of hyperbolicity, the SU(2) Skyrme model can never exhibit bulk violations of Einstein causality because its energy momentum tensor satisfies the dominant energy condition. It also satisfies the strong energy condition. The Born-Infeld-Skyrme model also satisfies both the dominant and strong energy conditions.