Getting the most out of dark matter observations and experiments

Who:  Annika Peter - (Caltech)
Where:  PRB 4138
When:  Tuesday, November 3, 2009 at 12:30
Type:  CCAPP Seminar

Description: Dark matter, constituting a fifth of the mass-energy in the Universe today, is one of the major "known unknowns" in physics. There are currently four approaches to determining the nature of dark matter, assuming it is composed of at least one new species of particle: 1) creation in collider experiments; 2) indirect detection via its annihilation products; 3) and direct detection; and 4) observations sensitive to the gravity of dark matter. For the latter three approaches, event rates are not only sensitive to the "physics" of dark matter (mass, cross sections, and the theory in which the dark matter particles live) but to the "astrophysics" of dark matter as well, namely the phase space density of dark matter throughout the Milky Way and other galaxies and its evolution through cosmic time. There is much theoretical uncertainty in phase space density, a fact which tends to either be ignored or simply acknowledged as a problem. I will highlight a few recent developments in understanding the local dark matter phase space density. Then, I will propose a shift in the way we think about uncertainties in the dark matter phase space density. Namely, we should be treating the astrophysics and physics properties of dark matter on equal footing, as things we want to derive from myriad data sets. I will show how this shift in thinking may yield more robust determinations of both the physics and astrophysics of dark matter, and show how this works in practice.