The Rabinowitz minimal periodic solution conjecture on partially convex reversible Hamiltonian systems and brake subharmonics
Yuting Zhou
TL;DR
This work advances the Rabinowitz minimal periodic solution conjecture for partially convex reversible Hamiltonian systems by developing a generalized mountain-pass essential point framework and a novel dual action functional that accommodates weaker regularity. It proves the existence of $T$-periodic brake solutions with minimal period $T$ for autonomous systems under a semidefinite $H_{pp}$ condition (or $n=1$), and it extends these results to brake subharmonics in nonautonomous reversible settings. A central novelty is the synthesis of a refined Morse index analysis with Maslov-type indices, including new iteration inequalities and a relative Morse index, enabling precise control of periodicity and the number of distinct subharmonics. The combination of variational methods, duality, and index theory yields both minimal-period results and a rich subharmonic structure, with significant implications for the study of symmetric Hamiltonian dynamics and brake orbits.
Abstract
Under weaker regularity and compactness assumptions, we find the mountain-pass essential point, which is a novel extension of the classical Ambrosetti-Rabinowitz mountain pass theorem. We study the reversible superquadratic autonomous Hamiltonian systems whose Hamiltonian $H(p,q)$ is strictly convex in the position $q\in\mathbf{R}^n$ and prove that for every $T>0$, the system has a $T$-periodic brake solution $\bar x$ with minimal period $T$, provided the Hessian $H_{pp}(\bar x(t))\in\mathbf{R}^{n\times n}$ is semi-positive definite for $t\in\mathbf{R}$ or $n=1$. For brake subharmonics of general reversible nonautonomous Hamiltonian systems, we also get some new results.
