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Mark Lovell
MPIA Heidelberg
It is well known that the number of Local Group galaxies is much smaller than the number density of dark matter haloes predicted by N-body cold dark matter simulations, and these same simulations often predict satellite central (<1kpc) densities higher than what we observe. Solutions to these problems include feedback from baryon processes, novel dark matter physics, and a combination of the two. In this talk I will review the status of baryon models, explain the likely impact of different dark matter candidates on the Local Group with a particular focus on the sterile neutrino, and present work comparing these models with observations.