Quantitative Spectral Stability for an Embedded Annulus under Coupled Curve Shortening and $2$D Ricci Flows
Mohammadjavad Habibivostakolaei
TL;DR
The paper analyzes how the Dirichlet spectrum of an embedded annulus evolves when its boundary undergoes curve shortening flow and the ambient metric evolves under the 2D Ricci flow. By combining variational formulas, Rellich-type identities, and harmonic capacity theory, it relates eigenvalue changes to the boundary modulus and a deficit functional, establishing a geometric stability result: for small deficit D, the annulus is conformally close to a flat cylinder and its first Dirichlet eigenvalue satisfies λ(A) ≥ λ_cyl(h) + C√D, where h is the modulus. The approach yields a quantitative spectral gap controlled by D and yields a precise link between conformal geometry and spectral stability under coupled geometric flows, complemented by numerical experiments that corroborate the δλ ∝ √D scaling in model geometries. This work highlights how modulus control and deficit quantify spectral sensitivity under evolving domains and metrics, with implications for stability analyses in geometric analysis and spectral geometry.
Abstract
We study the spectral stability of Dirichlet eigenvalues on an embedded annulus whose boundary evolves by curve shortening flow while the ambient surface evolves under the two dimensional Ricci flow using variational formulas, Rellich--type identities, and harmonic capacity methods, we relate eigenvalue variations to geometric deficit and modulus. We establish quantitative bounds comparing the spectrum of the evolving annulus with that of a flat cylinder of equal modulus. As a consequence, we obtain geometric stability and a spectral gap estimate controlled by the deficit functional.
