Twisted L-functions over number fields and Hilbert's eleventh problem.

link: http://arxiv.org/abs/0904.2429
Abstract

We prove a Burgess-like subconvex bound for twisted L-functions of a fixed
irreducible cuspidal automorphic representation of GL(2) over a totally real
number field. The proof is based on a spectral decomposition of shifted
convolution sums and a generalized Kuznetsov formula.