Hui Zhu
Let A be a supersingular abelian variety defined over a finite field k. We give an approximate description of the structure of the group A(k) of k-rational points of A in terms of the characteristic polynomial f of the Frobenius endomorphism of A relative to k. Write f=\prod g_i^{e_i} for distinct monic irreducible polynomials g_i and positive integers e_i, we show that there is a group homomorphism \varphi: A(k)--->\prod (\zz/g_i(1)\zz)^{e_i} that is ``almost'' an isomorphism in the sense that the size of the kernel and the cokernel of \varphi are bounded by an explicit function of dim A.