Noncommutativity and the lightfront

TL;DR

This paper explores how different limits in field theory, especially lightfront theory, relate through spectral flow, highlighting phenomena like lightlike noncommutativity and the significance of zero modes.

Contribution

It unifies various limits transforming configuration space into phase space via spectral flow, connecting lightfront field theory, noncommutativity, and background field effects.

Findings

Spectral flow unifies limits to phase space in field theory.

Lightlike noncommutativity arises from strong laser backgrounds.

Zero modes play a crucial role in lightfront quantization.

Abstract

We discuss various limits which transform configuration space into phase space, with emphasis on those related to lightfront field theory, and show that they are unified by spectral flow. Examples include quantising in `almost lightfront' coordinates and the appearance of lightlike noncommutativity from a strong background laser field. We compare this with the limit of a strong magnetic field, and investigate the role played by lightfront zero modes.