The spectral concentration for damped waves on compact Anosov manifolds
Yulin Gong
TL;DR
This work analyzes the high-frequency spectrum of the damped wave equation on compact Anosov manifolds, showing that most eigenvalues lie in a logarithmically narrow region near the average damping $-\overline{a}$ as $\Re \tau_n\to\infty$, with width $w(h)=|\log h|^{-{\frac{1-\alpha}{2}}}$ for any $0<\alpha<1$. The authors develop a semiclassical reduction and averaging scheme, then employ a moderate deviation principle for the Anosov geodesic flow to obtain quantitative concentration bounds, together with precise resolvent estimates for a perturbed damped operator. A key consequence is that nontrivial zeros of twisted Selberg zeta functions concentrate in a logarithmic region approaching $\Re s=\tfrac{1}{2}$ as $|\Im s|\to\infty$, linking spectral data of non-self-adjoint operators to dynamical properties of the geodesic flow. The results advance the understanding of resonance distributions in damped, non-self-adjoint systems and connect quantum-chaotic techniques with zeta-function phenomenology in hyperbolic geometry.
Abstract
We study the spectral distribution of damped waves on compact Anosov manifolds. Sjöstrand \cite{SJ1} proved that the imaginary parts of the majority of the eigenvalues concentrate near the average of the damping function, see also Anantharaman \cite{AN2}. In this paper, we prove that the most of eigenvalues actually lie in certain regions with imaginary parts that approach the average logarithmically as the real parts tend to infinity. The proof relies on the moderate deviation principles for Anosov geodesic flows. As an application, we show the concentration of non-trivial zeros of twisted Selberg zeta functions in a logarithmic region asymptotically close to $\Re s=\frac{1}{2}$.
