Inverse Compton constraints on the Dark Matter e+e- excesses

TL;DR

This paper investigates how gamma-ray observations constrain dark matter models that explain cosmic ray positron-electron excesses, finding significant exclusions for certain dark matter masses and profiles.

Contribution

It analyzes inverse Compton gamma-ray fluxes from dark matter annihilations and compares them with observational data to constrain dark matter properties.

Findings

Large parameter space excluded for dark matter masses > 1 TeV

Constraints are strong for leptonic annihilation channels

Certain dark matter density profiles are ruled out

Abstract

Recent results from experiments like PAMELA have pointed to excesses of e+e- in cosmic rays. If interpreted in terms of Dark Matter annihilations, they imply the existence of an abundant population of e+e- in the galactic halo at large. We consider the high energy gamma ray fluxes produced by Inverse Compton scattering of interstellar photons on such e+e-, and compare them with the available data from EGRET and some preliminary data from FERMI. We consider different observation regions of the sky and a range of DM masses, annihilation channels and DM profiles. We find that large portions of the parameter space are excluded, in particular for DM masses larger than 1 TeV, for leptonic annihilation channels and for benchmark Einasto or NFW profiles.