On the set of asymptotic homologies of orbits on invariant Lagrangian graphs

TL;DR

This paper investigates the asymptotic homologies of orbits on invariant Lagrangian graphs in torus cotangent bundles, establishing new results on their structure and implications for Mather measures and a conjecture on Hedlund Lagrangian tori.

Contribution

It introduces a proper cone in homology containing asymptotic homologies, extends results on Mather measures to 3D tori, and addresses a conjecture on Hedlund Lagrangian tori at supercritical energies.

Findings

Existence of a proper cone in homology containing asymptotic homologies.

If a rational vector is in the asymptotic homologies, the graph contains a Mather measure supported on a periodic orbit.

Partial resolution of Carneiro-Ruggiero's conjecture on Hedlund Lagrangian tori.

Abstract

Given a smooth Tonelli Hamiltonian on the torus $\mathbb{T}^{n}$ and a $C^{2}$ Lagrangian graph $W \subset T^{*}\mathbb{T}^{n}$ that is invariant under the Hamiltonian flow and contained within a Ma\~n\'e supercritical energy level, we demonstrate the existence of a proper cone in the first real homology group $H_1(\mathbb{T}^n,\mathbb{R})$ that contains the asymptotic homologies of the canonical projections of recurrent orbits in $W$. Additionally, for invariant Lagrangian graphs on $\mathbb{T}^{3}$, drawing on Franks' theory of the rotation set of homeomorphisms of $\mathbb{T}^{2}$ homotopic to the identity, we show that under certain assumptions for an invariant Lagrangian graph on $\mathbb{T}^{3}$, if there exists a rational vector in homology contained in the set of asymptotic homologies of orbits on the Lagrangian graph, then the graph contains a Mather measure supported on a periodic orbit. This result generalizes a well-known fact for Lagrangian graphs on $\mathbb{T}^{2}$. Finally, we exploit these results for three dimensional tori to give a partial answer to a conjecture by Carneiro-Ruggiero about the non-existence of Hedlund Lagrangian tori at supercritical energy levels.