Cosmic-Ray Cooling in Active Galactic Nuclei as a New Probe of Inelastic Dark Matter

TL;DR

This paper introduces a new method to investigate inelastic dark matter by analyzing cosmic-ray cooling effects in active galactic nuclei, offering constraints beyond traditional detection techniques.

Contribution

It demonstrates that AGN cosmic-ray cooling bounds can probe large mass splittings in inelastic dark matter, surpassing direct detection limits and complementing collider searches.

Findings

AGN cooling bounds constrain large mass splittings ($gtrsim$ TeV) in inelastic DM.

Multimessenger data from NGC 1068 and TXS 0506+056 provide new limits.

Cooling bounds can also probe thermal light DM with small mass splittings.

Abstract

We present a novel way to probe inelastic dark matter using cosmic-ray (CR) cooling in active galactic nuclei (AGNs). Dark matter (DM) in the vicinity of supermassive black holes may scatter off CRs, resulting in the rapid cooling of CRs for sufficiently large cross sections. This in turn can alter the high-energy neutrino and gamma-ray fluxes detected from these sources. We show that AGN cooling bounds obtained through the multimessenger data of NGC 1068 and TXS 0506+056 allow to reach unprecedently large mass splittings for inelastic DM ($\gtrsim$ TeV), orders of magnitude larger than those probed by direct detection experiments and DM capture in neutron stars. Furthermore, we demonstrate that cooling bounds from AGNs can probe thermal light DM with small mass splittings. This provides novel and complementary constraints in parts of a parameter space accessible solely by colliders and beam dump experiments.