26-30 July 2010
Montpellier 2 University
Europe/Paris timezone

Indirect searches of dark matter

27 Jul 2010, 16:30
20m
Salle des Actes (Montpellier 2 University)

Salle des Actes

Montpellier 2 University

Place Eugene Bataillon, 34095 Montpellier Cedex 5 FRANCE

Speaker

Mr Le Zhang (University of Hamburg, II. Institute for Theoretical Physics)

Description

If dark matter decays into electrons and positrons, it can affect Galactic radio emissions and gamma ray fluxes as well as the local cosmic ray fluxes. We propose a new, more general analysis of constraints on dark matter. The constraints can be obtained for any decaying dark matter model by convolving the specific dark matter decay spectrum with a response function. We derive this response function from full-sky radio and gamma ray surveys as well as from the positron flux recently reported by PAMELA. We discuss the influence of astrophysical uncertainties on the response function, such as from propagation and from the profiles of the dark matter and the Galactic magnetic field. As an application, we find that some widely used dark matter decay scenarios can be ruled out under modest assumptions. We also calculate intensity and angular power spectrum of the cosmological background of synchrotron emission from cold dark matter annihilations into electron positron pairs. We compare this background with intensity and anisotropy of astrophysical and cosmological radio backgrounds. Under modest assumptions for the dark matter clustering we find that around 2 GHz average intensity and fluctuations of the radio background at sub-degree scales allows to probe dark matter masses >100 GeV and annihilation cross sections not far from the natural values <sigma v> ~ 3 x 10^(-26) cm^3/s.

Primary author

Mr Le Zhang (University of Hamburg, II. Institute for Theoretical Physics)

Co-authors

Dr Christoph Weniger (DESY) Prof. Guenter Sigl (University of Hamburg, II. Institute for Theoretical Physics) Dr Javier Redondo (DESY) Dr Luca Maccione (DESY)

Presentation Materials