Low energy resolvent estimates for slowly decaying attractive potentials
Kenichi Ito, Tomoya Tagawa
TL;DR
The paper develops uniform low-energy resolvent estimates for Schrödinger operators with slowly decaying attractive potentials by employing the Ito–Skibsted commutator method, avoiding microlocal machinery. It proves Rellich’s theorem, the limiting absorption principle, radiation condition bounds, and Sommerfeld’s uniqueness under $C^2$ regularity and spherical symmetry, with a short-range perturbation, via Agmon– Hörmander spaces. A central theme is the construction of an effective time via the eikonal phase $S(\lambda,x)$ and the associated distorted commutator estimates, which yield a priori decay, absence of positive eigenvalues, and robust LAP bounds at low energy. The results have implications for spectral and scattering theory in slowly decaying regimes and demonstrate a simpler route to sharp low-energy estimates without microlocal tools.
Abstract
We discuss the low energy resolvent estimates for the Schrödinger operator with slowly decaying attractive potential. The main results are Rellich's theorem, the limiting absorption principle and Sommerfeld's uniqueness theorem. For the proofs we employ an elementary commutator method due to Ito--Skibsted, for which neither of microlocal or functional-analytic techniques is required.
