Aspects of Duality and Confining Strings

TL;DR

This paper investigates the excitation spectrum of confining strings using an effective field theory, revealing duality invariance and proposing a simple spectral function form that may be exact in Yang-Mills theory.

Contribution

It introduces a duality-invariant spectral function model for confining strings and suggests its exactness in Yang-Mills theory, supported by numerical simulations.

Findings

Spectral function approximated by a rational form

Duality invariance under string twisting and bending

Proposed spectral function becomes exact in Yang-Mills theory

Abstract

We inspect the excitation energy spectrum of a confining string in terms of solitons in an effective field theory model. The spectrum can be characterized by a spectral function, and twisting and bending of the string is manifested by the invariance of this function under a duality transformation. Both general considerations and numerical simulations reveal that the spectral function can be approximated by a simple rational form, which we propose becomes exact in the Yang-Mills theory.