Reeb orbits frequently intersecting a symplectic surface
Michael Hutchings
TL;DR
This work proves that in a closed 3D contact manifold with a symplectic surface boundary on Reeb orbits, and under a niceness condition near the boundary, there exists a Reeb orbit intersecting the surface with a frequency lower bound given by $\operatorname{Area}(\Sigma,d\lambda)/\operatorname{vol}(Y,\lambda)$, independent of genericity assumptions. The authors’ approach hinges on inflating the contact form near the surface and leveraging Weyl laws for elementary spectral invariants and their interaction with alternative ECH capacities to force the bound. The result yields a broad generalization relating mean action and the Calabi invariant for area-preserving diffeomorphisms and illustrates a robust link between geometric intersection data and spectral invariants in contact geometry. The paper also outlines open questions, including removing the niceness hypothesis, achieving reverse inequalities, and extending the framework to higher dimensions, with potential implications for geodesic and Hamiltonian dynamics beyond the current setting.
Abstract
Consider a symplectic surface in a three-dimensional contact manifold with boundary on Reeb orbits (periodic orbits of the Reeb vector field). We assume that the rotation numbers of the boundary Reeb orbits satisfy a certain inequality, and we also make a technical assumption that the Reeb vector field has a particular ``nice'' form near the boundary of the surface. We then show that there exist Reeb orbits which intersect the interior of the surface, with a lower bound on the frequency of these intersections in terms of the symplectic area of the surface and the contact volume of the three-manifold. No genericity of the contact form is assumed. As a corollary of the main result, we obtain a generalization of various recent results relating the mean action of periodic orbits to the Calabi invariant for area-preserving surface diffeomorphisms.
