# Axion-Like Particles and Recent Observations of the Cosmic Infrared Background Radiation

## TL;DR

This paper explores how axion-like particles could resolve the discrepancy between observed cosmic infrared background radiation and TeV gamma-ray attenuation, suggesting new physics in axion parameter space.

## Contribution

It proposes a specific axion parameter space that can reconcile the observed cosmic infrared background with TeV gamma-ray transparency.

## Key findings

- Identifies axion mass range $7 imes 10^{-10}$ to $5 imes 10^{-8}$ eV.
- Determines axion-photon coupling constant range $1.2 imes 10^{-11}$ to $8.8 imes 10^{-10}$ GeV$^{-1}$.
- Suggests axion-photon mixing increases universe transparency for TeV gamma-rays.

## Abstract

The CIBER collaboration released their first observational data of the Cosmic IR background (CIB) radiation, which has significant excesses at around the wavelength $\sim$ 1 $\mu$m compared to theoretically-inferred values. The amount of the CIB radiation has a significant influence on the opaqueness of the Universe for TeV gamma-rays emitted from distant sources such as AGNs. With the value of CIB radiation reported by the CIBER experiment, through the reaction of such TeV gamma-rays with the CIB photons, the TeV gamma-rays should be significantly attenuated during propagation, which would lead to energy spectra in disagreement with current observations of TeV gamma ray sources. In this article, we discuss a possible resolution of this tension between the TeV gamma-ray observations and the CIB data in terms of axion [or Axion-Like Particles (ALPs)] that may increase the transparency of the Universe by the anomaly-induced photon-axion mixing. We find a region in the parameter space of the axion mass, $m_a \sim 7 \times 10^{-10} - 5 \times 10^{-8}$eV, and the axion-photon coupling constant, $1.2 \times 10^{-11} {\rm GeV}^{-1} \lesssim g_{a\gamma} \lesssim 8.8 \times 10^{-10} {\rm GeV}^{-1}$ that solves this problem.