文摘
Using an estimate on the number of critical points for a Morse-even function on the sphere 18ea60004f61f2cf8875de8038" title="Click to view the MathML source">Sm, m≥1, we prove a multiplicity result for orthogonal geodesic chords in Riemannian manifolds with boundary that are diffeomorphic to Euclidean balls. This yields also a multiplicity result for brake orbits in a potential well.