THE UNIVERSE'S EVOLUTION BEFORE BIG BANG NUCLEOSYNTHESIS (BBN) IS UNKNOWN. DARK MATTER MICROHALOS PROVIDE A WINDOW INTO THIS PERIOD BECAUSE THEIR SEED FLUCTUATIONS BEGIN TO GROW PRIOR TO BBN. CONSEQUENTLY AN EARLY MATTER-DOMINATED EPOCH DRAMATICALLY ENHANCES THE MICROHALO ABUNDANCE WITHIN DWARF SPHEROIDAL GALAXIES (DSPHS) AND SIGNIFICANTLY BOOSTS THE DARK MATTER ANNIHILATION RATE WITHIN THESE SYSTEMS. SINCE THE MICROHALOS TRACK THE DENSITY OF THE HOST HALO THE MORPHOLOGY OF THIS SIGNAL IS EXTREMELY DIFFUSE AND EXISTING DSPH CONSTRAINTS CANNOT CONSTRAIN THESE MODELS. WE PROPOSE TO SIGNIFICANTLY ENHANCE THE JOINT LIKELIHOOD ANALYSIS OF FERMI-LAT DSPH OBSERVATIONS TO DETECT OR CONSTRAIN DARK MATTER ANNIHILATION SIGNALS FROM COSMOLOGIES THAT INCLUDE AN EARLY MATTER- DOMINATED EPOCH.

University Of North Carolina At Chapel Hill, Chapel Hill NC

Investigators