%0 Journal Article %T A PDE approach to space-time fractional parabolic problems %A Ricardo H. Nochetto %A Enrique Otarola %A Abner J. Salgado %J Mathematics %D 2014 %I arXiv %X We study solution techniques for parabolic equations with fractional diffusion and Caputo fractional time derivative, the latter being discretized and analyzed in a general Hilbert space setting. The spatial fractional diffusion is realized as the Dirichlet-to-Neumann map for a nonuniformly elliptic problem posed on a semi-infinite cylinder in one more spatial dimension. We write our evolution problem as a quasi-stationary elliptic problem with a dynamic boundary condition. We propose and analyze an implicit fully-discrete scheme: first-degree tensor product finite elements in space and an implicit finite difference discretization in time. We prove stability and error estimates for this scheme. %U http://arxiv.org/abs/1404.0068v3