Cosmic infrared background excess from axion-like particles and implications for multi-messenger observations of blazars

TL;DR

This paper explores whether axion-like particles can explain the excess cosmic infrared background detected by CIBER, and discusses implications for multi-messenger astrophysics including blazar observations and gamma-ray attenuation.

Contribution

It extends previous ALP decay models to include warm relic populations and assesses their consistency with anisotropy, stellar cooling, and gamma-ray observations.

Findings

ALP decay can account for the infrared excess without conflicting with anisotropy constraints.

Increased EBL from ALPs does not contradict blazar spectra observations.

Enhanced EBL reduces TeV gamma-ray flux and helps reconcile neutrino and gamma-ray data.

Abstract

The first measurement of the diffuse background spectrum at 0.8-1.7 $\mu \rm{m}$ from the CIBER experiment has revealed a significant excess of the cosmic infrared background (CIB) radiation compared to the theoretically expected spectrum. We revisit the hypothesis that decays of axionlike particle (ALP) can explain this excess, extending previous analyses to the case of a warm relic population. We show that such a scenario is not excluded by anisotropy measurements nor by stellar cooling arguments. Moreover, we find that the increased extragalactic background light (EBL) does not contradict observations of blazar spectra. Furthermore, the increased EBL attenuates the diffuse TeV gamma-ray flux and alleviates the tension between the detected neutrino and gamma ray fluxes.