Nambu-Goldstone and Massive Modes in Gravitational Theories with Spontaneous Lorentz Breaking

TL;DR

This paper explores the consequences of spontaneous Lorentz symmetry breaking in gravitational theories, focusing on the behavior of Nambu-Goldstone modes, potential Higgs mechanisms, and the emergence of massive modes.

Contribution

It provides a summary of recent research addressing the fate of Nambu-Goldstone modes and the possibility of Higgs-like mechanisms in theories with spontaneous Lorentz breaking.

Findings

Nambu-Goldstone modes can manifest in specific ways under Lorentz breaking.

Higgs mechanisms may or may not occur depending on the model details.

Massive modes analogous to the Higgs particle can appear in these theories.

Abstract

Spontaneous breaking of local Lorentz symmetry is of interest as a possible mechanism originating from physics at the Planck scale. If such breaking occurs, however, it raises the questions of what the fate of the Nambu-Goldstone modes is, whether a Higgs mechanism can occur, and whether additional massive modes (analogous to the Higgs particle) can appear. A summary of some recent work looking at these questions is presented here.