Astrophysical Tests of Lorentz and CPT Violation with Photons

TL;DR

This paper develops a comprehensive framework for testing Lorentz invariance violations in electromagnetic waves, using astrophysical observations to set constraints on various theoretical operators and searching for potential violations.

Contribution

It introduces a general method to test Lorentz and CPT violation with photons across operators of any mass dimension, applying it to astrophysical data.

Findings

No evidence for isotropic Lorentz violation.

Constraints on operators of dimension 6 and 8 from gamma-ray bursts.

Stringent limits on dimension 3 operators from WMAP data.

Abstract

A general framework for tests of Lorentz invariance with electromagnetic waves is presented, allowing for operators of arbitrary mass dimension. Signatures of Lorentz violations include vacuum birefringence, vacuum dispersion, and anisotropies. Sensitive searches for violations using sources such as active galaxies, gamma-ray bursts, and the cosmic microwave background are discussed. Direction-dependent dispersion constraints are obtained on operators of dimension 6 and 8 using gamma-ray bursts and the blazar Markarian 501. Stringent constraints on operators of dimension 3 are found using 5-year data from the Wilkinson Microwave Anisotropy Probe. No evidence appears for isotropic Lorentz violation, while some support at one sigma is found for anisotropic violation.