Subconvexity for -functions in spectral aspect
arXiv:2010.10153
Abstract
Let be a holomorphic cusp form or the Eisenstien series and be a Hecke-Maass cusp form with its Langlands parameter in generic position i.e. away from Weyl chamber walls and away from self dual forms. We study an amplified second moment and deduce the subconvexity bound \begin{equation*} L(1/2,π\times f)\ll_{f,ε} \|μ\|^{3/2-1/2022+ε}. \end{equation*} As a corollary, when , we also obtain the subconvexity bound \begin{equation*} L(1/2,π)\ll_ε \|μ\|^{3/4-1/4044+ε}. \end{equation*}
Computations for f Eisenstein added. Arguments in stationary phase analysis corrected. Final bound updated