Lorentz Violation: Motivation and new constraints

TL;DR

This paper reviews motivations for Lorentz violation, explores theoretical frameworks including effective field theory, and summarizes current observational constraints from high-energy astrophysics, highlighting the field's status and future directions.

Contribution

It provides a comprehensive review of theoretical motivations, frameworks, and the latest observational constraints on Lorentz violation at the Planck scale.

Findings

Current astrophysical observations set strong limits on Lorentz-violating operators.

Effective Field Theory can incorporate Lorentz violation with viable theoretical models.

Recent constraints significantly restrict possible Lorentz-violating effects in quantum electrodynamics.

Abstract

We review the main theoretical motivations and observational constraints on Planck scale suppressed violations of Lorentz invariance. After introducing the problems related to the phenomenological study of quantum gravitational effects, we discuss the main theoretical frameworks within which possible departures from Lorentz invariance can be described. In particular, we focus on the framework of Effective Field Theory, describing several possible ways of including Lorentz violation therein and discussing their theoretical viability. We review the main low energy effects that are expected in this framework. We discuss the current observational constraints on such a framework, focusing on those achievable through high-energy astrophysics observations. In this context we present a summary of the most recent and strongest constraints on QED with Lorentz violating non-renormalizable operators. Finally, we discuss the present status of the field and its future perspectives.