Magnetic uncertainty in variable geometry

TL;DR

This paper investigates Hardy-type uncertainty principles and unique continuation for variable-coefficient covariant Schrödinger and heat equations with magnetic potentials, extending previous results and addressing new challenges from variable metrics and magnetic interactions.

Contribution

It extends existing uncertainty principles to variable-coefficient magnetic Schrödinger and heat equations, introducing new techniques to handle variable metrics and magnetic effects.

Findings

Solutions with super-quadratic decay at two times must vanish

Established Hardy-type results at quadratic exponential scale under structural assumptions

Unified and extended previous constant and non-magnetic coefficient results

Abstract

In this paper, we study Hardy-type uncertainty principles and unique continuation properties for linear covariant Schrodinger equations with variable coefficients in the presence of bounded electric and magnetic potentials. Under suitable smallness assumptions on the leading coefficients, we prove that any solution exhibiting super-quadratic exponential decay at two distinct times must vanish identically. Under an additional structural assumption on the coefficient matrix $G$, we further establish a Hardy-type result at the quadratic exponential scale. We also obtain an analogous uniqueness result for the heat equation with variable-coefficient magnetic perturbations. Our results unify and extend previous works in two directions: they recover the constant-coefficient covariant case treated by Barcelo-Fanelli-Gutierrez-Ruiz-Vilela when $G=I$, and the variable-coefficient non-magnetic case considered by Federico-Li-Yu when $A=0$. The proofs combine logarithmic convexity arguments with Carleman estimates adapted to variable-coefficient covariant Schr\"odinger and parabolic flows. Although our approach follows the general strategy introduced by Escauriaza-Kenig-Ponce-Vega, substantial new difficulties arise from the interaction between the variable metric and the magnetic structure, which requires new weight functions and refined commutator estimates.