%0 Journal Article %T The trace formula and the existence of PEL type Abelian varieties modulo p %A Arno Kret %J Mathematics %D 2012 %I arXiv %X We show, using the trace formula, that any Newton stratum of a Shimura variety of PEL-type of types (A) and (C) is non-empty at the primes of good reduction. Furthermore we prove conditionally the non-emptiness for Shimura data associated to odd Spin groups. Our results are conditional on Rapoport-Langlands conjecture and Arthur's conjectures on the discrete spectrum. Both these results have been announced by Arthur and Kisin in significant cases. %U http://arxiv.org/abs/1209.0264v2