%0 Journal Article
%T On finiteness of endomorphism rings of abelian varieties
%A Chia-Fu Yu
%J Mathematics
%D 2009
%I arXiv
%X The endomorphism ring End(A) of an abelian variety A is an order in a semi-simple algebra over Q. The co-index of End(A) is the index to a maximal order containing it. We show that for abelian varieties of fixed dimension over any algebraically closed field of characteristic p>0, the p-exponents of the co-indices of their endomorphism rings are bounded. We also give a few applications to this finiteness result.
%U http://arxiv.org/abs/0905.0019v5