On the antimatter signatures of the cosmological dark matter subhalos

TL;DR

This paper reviews how dark matter subhalos influence antimatter signals, highlighting theoretical limits on antimatter enhancement and discussing discrepancies between simulations and observations.

Contribution

It provides a theoretical analysis of antimatter signatures from dark matter subhalos and compares simulation predictions with observational data.

Findings

Antimatter yield enhancement from subhalos is limited to about 20.

Discrepancies exist between N-body simulation profiles and Milky Way observations.

Predictions for supersymmetric models suggest potential observability at the LHC.

Abstract

While the PAMELA collaboration has recently confirmed the cosmic ray positron excess, it is interesting to review the effects of dark matter (DM) subhalos on the predicted antimatter signals. We recall that, according to general subhalo properties as inferred from theoretical cosmology, and for DM with constant annihilation cross section, the enhancement cannot be $\gtrsim$ 20 for the antimatter yield. This bound is obviously different from that found for gamma-rays. We also recall some predictions for supersymmetric benchmark models observable at the LHC and derived in the cosmological N-body framework, illustrating in the meantime the existing discrepancy between the profiles derived from N-body experiments and the current observations of the Milky Way.