Using a simple relative trace
formula, we compute averages of twisted modular L-values for newforms of cubic
level. In the case of Maass forms, we obtain an exact formula. For holomorphic
forms of weight k > 2, we obtain an asymptotic formula, which agrees with
the estimate predicted by the Lindelöf hypothesis in the weight and level
aspects.
Keywords
L-functions, relative trace
formula, supercuspidal representations, Maass forms