Lorentz-violating contributions of the Carroll-Field-Jackiw model to the CMB anisotropy

TL;DR

This paper investigates how Lorentz-violating modifications in the Maxwell-Carroll-Field-Jackiw model affect the CMB spectrum, revealing anisotropies and setting bounds on Lorentz violation parameters.

Contribution

It provides a finite temperature analysis of the MCFJ model, deriving modified black body spectra and constraining Lorentz-violating parameters based on CMB observations.

Findings

The spectrum becomes anisotropic with Lorentz violation.

Lorentz-breaking effects are nonlinear in frequency and quadratic in temperature.

Lorentz violation cannot account for observed CMB anisotropy levels.

Abstract

We study the finite temperature properties of the Maxwell-Carroll-Field-Jackiw (MCFJ) electrodynamics for a purely spacelike background. Starting from the associated finite temperature partition function, a modified black body spectral distribution is obtained. We thus show that, if the CMB radiation is described by this model, the spectrum presents an anisotropic angular energy density distribution. We show, at leading order, that the Lorentz-breaking contributions for the Planck's radiation law and for the Stefan-Boltzmann's law are nonlinear in frequency and quadratic in temperature, respectively. Using our results, we set up bounds for the Lorentz-breaking parameter, and show that Lorentz violation in the context of the MCFJ model is unable to yield the known CMB anisotropy (of 1 part in $10^{5})$.