Extragalactic gamma-ray signal from dark matter annihilation: an appraisal

Abstract

We revisit the computation of the extragalactic gamma-ray signal from cosmological dark matter annihilations. The prediction of this signal is notoriously model depen-dent, due to different descriptions of the clumpiness of the dark matter distribution at small scales, responsible for an enhancement with respect to the smoothly dis-tributed case. We show how a direct computation of this “flux multiplier ” in terms of the nonlinear power spectrum offers a conceptually simpler approach and may ease some problems, such as the extrapolation issue. In fact very simple analytical recipes to construct the power spectrum yield results similar to the popular Halo Model expectations, with a straightforward alternative estimate of errors. For this specific application, one also obviates to the need of identifying (often literature-dependent) concepts entering the Halo Model, to compare different simulations. Key words: Cosmology: theory–dark matter–gamma-rays: diffuse background

Similar works

Full text

thumbnail-image
oai:CiteSeerX.psu:10.1.1.768.5496Last time updated on 10/30/2017

This paper was published in CiteSeerX.

Having an issue?

Is data on this page outdated, violates copyrights or anything else? Report the problem now and we will take corresponding actions after reviewing your request.