$L^2$ restriction bounds for analytic continuations of quantum ergodic Laplace eigenfunctions
John A. Toth, Xiao Xiao
TL;DR
The paper develops a 2-microlocal quantum ergodic restriction (2MQER) theory for analytic continuations of QE Laplace eigenfunctions on Grauert tubes by analyzing the FBI transform $T_{hol}(h)$. It proves that the restricted data $T_{Σ}u_h$ satisfies a semiclassical asymptotic formula with a density $q$ on $Σ$, captured by a pseudodifferential operator ${ olinebreak[4]{ ext{P}}}_{Σ,a}(h)$, and identifies the 2-microlocal mass distribution through the integral over $S^*M∩Σ$. The work then derives sharp $L^2$-restriction bounds for $igl\|T_{Σ}u_higr\|_{L^2(Σ)}$, including a universal upper bound $igo(h^{-1/2})$, a positive lower bound, and improved upper bounds under transversality-type geometric conditions, with weighted $L^2$ estimates for the complexified eigenfunctions. Collectively, these results advance understanding of how QE eigenfunctions behave under analytic continuation and restriction, providing tools for spectral geometry and nodal analysis in the analytic setting.
Abstract
We prove a quantum ergodic restriction (QER) theorem for real hypersurfaces $Σ\subset X,$ where $X$ is the Grauert tube associated with a real-analytic, compact Riemannian manifold. As an application, we obtain $h$ independent upper and lower bounds for the $L^2$ - restrictions of the FBI transform of Laplace eigenfunctions restricted to $Σ$ satisfying certain generic geometric conditions.
