Strong Uniqueness for Schrِdinger Operators with Kato Potentials

We prove a strong unique continuation result for Schrödinger inequalities, i.e., we obtain that a flat u so that |Δu| ≤|Vu| should be zero, provided that V is a radial Kato potential. It gives an extension of a result by E. B. Fabes, N. Garofalo and F. H. Lin [3] who got a weak local uniqueness theorem. Our method relies on sharp Carleman estimates.