Marked length spectrum rigidity in nonpositive curvature with singularities

Abstract

Combining several previously known arguments, we prove marked length spectrum rigidity for surfaces with nonpositively curved Riemannian metrics away from a finite set of cone-type singularities with cone angles $>2\pi$. With an additional condition, we can weaken the requirement on one metric to `no conjugate points.'

21 pages, 7 figures