Quantitative Stability for Yamabe minimizers on manifolds with boundary
Benjamín Borquez, Rayssa Caju, Hanne Van Den Bosch
TL;DR
This work develops a quantitative stability theory for Escobar's Yamabe-type energy on compact manifolds with boundary by reducing to a boundary functional via harmonic extension and Lyapunov–Schmidt reduction. It proves that the energy deficit controls the distance to the minimizer set with a power 2+γ, where γ≥0 and may be positive under Adams–Simon-type nondegeneracy, and it establishes a conformally invariant stability bound as a corollary. The analysis combines local boundary stability with a global compactness argument to obtain a robust stability inequality for the Escobar energy, and it verifies the sharp γ=0 ball case while clarifying the role of the boundary in the stability landscape. The framework links sharp trace Sobolev inequalities, Dirichlet-to-Neumann maps, and Adams–Simon positivity to illuminate stability phenomena for scalar-flat metrics with prescribed boundary mean curvature.
Abstract
This paper addresses the quantitative stability for a Yamabe-type functional on compact manifolds with boundary introduced by Escobar. Minimizers of the functional correspond to scalar-flat metrics with constant mean curvature on the boundary. We prove that the deficit controls the distance to the minimizing set to a suitable power by reducing the problem to the analogous question for an effective functional on the boundary.
