On dark matter and the cosmic antimatter spectrum -- Julien Lavalle (Università Di Torino)

jeudi 4 déc. 2008, 15:00 → 16:00 Europe/Paris

Salle Grossetête (LPNHE)

While the PAMELA collaboration has just released the most recent measurements of the cosmic ray positron, seemingly indicating an excess between 10 GeV to 270 GeV with respect to the current predictions of the secondary positron background, it is important to review the processes at stake when deriving any prediction of cosmic antimatter fluxes related to dark matter annihilation. We will focus on positrons and antiprotons, recalling (i) our recent estimate of the positron background with the associated theoretical uncertainties, and showing (ii) that some enhancement of the signals due to cosmological subhalos is unlikely (iii) that gamma-ray (and antiproton) constraints may already exclude a large amount of models proposed in the literature to explain the positron excess. We will also shortly discuss the proposal of using the SZ effect induced by primary electrons and positrons orignating from dark matter annihilation in clusters of galaxies. Finally we will summarize the spectral zones where convincing hints for dark matter annihilation can still occur, emphasizing, of course, the importance of the complementarity between the different detection methods.

Slides lavalle_LPNHE_04122008.pdf