Continuous variation of eigenvalues and Gårding's inequality
Let \(D_t\) be a smooth 1-parameter family of elliptic selfadjoint partial differential operators on a compact manifold without boundary. We use Gårding's inequality to give a simple proof that the \(k\)th eigenvalue of \(D_t\) is continuous in \(t\).
scientific article; zbMATH DE number 1308148