2025/10/13 by Butt, Karen, Erchenko, Alena, Humbert, Tristan +2 · 1 citation
#37C27 #37D40 #53C22 #53C24 #53C35 #Differential Geometry (math.DG) #Dynamical Systems (math.DS) #FOS: Mathematics #Spectral Theory (math.SP)
paper · doi:10.48550/arxiv.2510.11399
Let M be a compact manifold without boundary equipped with a Riemannian metric g of negative curvature. In this paper, we introduce the marked Poincaré determinant (MPD), a homothety invariant of g depending on differentiable periodic data of its geodesic flow. The MPD associates to each free homotopy class of closed curves in M a number which measures the unstable volume expansion of the geodesic flow along the associated closed geodesic. We prove a local MPD rigidity result in dimension 3: if g is sufficiently close to a hyperbolic metric g0 and both metrics have the same MPD, then they are homothetic. As a by-product of our proof, we show the Lichnerowicz Laplacian of g0 is injective on the space of trace-free divergence-free symmetric 2-tensors, which, to our knowledge, is the first result of its kind in negative curvature.