%0 Journal Article %T Ranks of Jacobians in towers of function fields %A Douglas Ulmer %A Yuri G. Zarhin %J Mathematics %D 2010 %I arXiv %X Let $k$ be a field of characteristic zero and let $K=k(t)$ be the rational function field over $k$. In this paper we combine a formula of Ulmer for ranks of certain Jacobians over $K$ with strong upper bounds on endomorphisms of Jacobians due to Zarhin to give many examples of higher dimensional, absolutely simple Jacobians over $k(t)$ with bounded rank in towers $k(t^{1/p^r})$. In many cases we are able to compute the rank at every layer of the tower. %U http://arxiv.org/abs/1002.3318v2