Bounds for the periods of eigenfunctions on arithmetic hyperbolic 3-manifolds over surfaces
Jiaqi Hou
TL;DR
The paper studies period bounds for Hecke-Maass forms on compact arithmetic hyperbolic 3-manifolds restricted to totally geodesic surfaces. It implements the arithmetic amplification method of Iwaniec–Sarnak, translating the period into a pretrace kernel and then bounding the geometric side via Hecke returns and oscillatory integrals. A detailed stationary-phase analysis, including Morse–Bott degeneracies, yields a power-saving λ^{-1/74+ε} over the local bound, with a careful division of nondegenerate and degenerate regimes. The results advance restriction-type estimates for automorphic forms on higher-rank arithmetic manifolds and relate to automorphic distinction principles and period formulas in special cases.
Abstract
Let $ψ$ be a Hecke-Maass form on a compact congruence arithmetic hyperbolic 3-manifold $X$, and let $Y$ be a hyperbolic surface in $X$ that is not necessarily closed. We obtain a power saving result over the local bound for the period of $ψ$ along $Y$, by applying the method of arithmetic amplification developed by Iwaniec and Sarnak.
