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We prove an extension of the homology version of the Hofer–Zehnder conjecture proved by Shelukhin to the weighted projective spaces which are symplectic orbifolds. In particular, we prove that if the number of fixed points counted with their isotropy order as multiplicity of a non-degenerate Hamiltonian diffeomorphism of such a space is larger than the minimum number possible, then there are infinitely many periodic points.

We study in detail the dynamics of conformal Hamiltonian flows that are defined on a conformal symplectic manifold (this notion was popularized by Vaisman in 1976). We show that they exhibit some conservative and dissipative behaviours. We also build many examples of various dynamics that show simultaneously their difference and resemblance with the contact and symplectic case.

We prove an extension of the homology version of the Hofer-Zehnder conjecture proved by Shelukhin to the weighted projective spaces which are symplectic orbifolds. In particular, we prove that if the number of fixed points counted with their isotropy order as multiplicity of a non-degenerate Hamiltonian diffeomorphism of such a space is larger than the minimum number possible, then there are infinitely many periodic points.

We show that every forward complete Finsler manifold of infinite fundamental group and not homotopy-equivalent to \\(S^1\\) has infinitely many geometrically distinct geodesics joining any given pair of points \\(p\\) and \\(q\\). In the special case in which \\(\\beta_1(M;\\mathbb{Z})\\geq 1\\) and \\(M\\) is closed, the number of geometrically distinct geodesics between two points grows at least logarithmically.

We provide a contact analogue of the symplectic camel theorem that holds in \\(\\mathbb{R}^{2n}\\times S^1\\), and indeed generalize the symplectic camel. Our proof is based on the generating function techniques introduced by Viterbo, extended to the contact case by Bhupal and Sandon, and builds on Viterbo's proof of the symplectic camel.

In this article, we study conjectures of Sandon on the minimal number of translated points in the special case of the unit tangent bundle of a Riemannian manifold. We restrict ourselves to contactomorphisms of \\(SM\\) that lift diffeomorphisms of \\(M\\) homotopic to identity. We prove that there exist sequences \\((p_n,t_n)\\) where \\(p_n\\) is a translated point of time-shift \\(t_n\\) with \\(t_n\\to+\\infty\\) for a large class of manifolds. We also prove Morse estimates on the number of translated points in the case of Zoll Riemannian manifolds.

We use generating function techniques developed by Givental, Théret and ourselves to deduce a proof in \\(\\mathbb{C}\\text{P}^d\\) of the homological generalization of Franks theorem due to Shelukhin. This result proves in particular the Hofer-Zehnder conjecture in the non-degenerated case: every Hamiltonian diffeomorphism of \\(\\mathbb{C}\\text{P}^d\\) that has at least \\(d+2\\) non-degenerated periodic points has infinitely many periodic points. Our proof does not appeal to Floer homology or the theory of \\(J\\)-holomorphic curves. An appendix written by Shelukhin contains a new proof of the Smith-type inequality for barcodes of Hamiltonian diffeomorphisms that arise from Floer theory, which lends itself to adaptation to the setting of generating functions.

In this article, we give multiple situations when having one or two geometrically distinct closed geodesics on a complete Riemannian cylinder \\(M\\simeq S^1\\times\\mathbb{R}\\) or a complete Riemannian plane \\(M\\simeq\\mathbb{R}^2\\) leads to having infinitely many geometrically distinct closed geodesics. In particular, we prove that any complete cylinder with isolated closed geodesics has zero, one or infinitely many homologically visible closed geodesics; this answers a question of Alberto Abbondandolo.

In this article, we prove that every contactomorphism of any standard contact lens space of dimension \\(2n-1\\) that is contact-isotopic to identity has at least \\(2n\\) translated points. This sharp lower bound refines a result of Granja-Karshon-Pabiniak-Sandon and answers a conjecture of Sandon positively.

We study the notion of orderability of isotopy classes of Legendrian submanifolds and their universal covers, with some weaker results concerning spaces of contactomorphisms. Our main result is that orderability is equivalent to the existence of spectral selectors analogous to the spectral invariants coming from Lagrangian Floer Homology. A direct application is the existence of Reeb chords between any closed Legendrian submanifolds of a same orderable isotopy class. Other applications concern the Sandon conjecture, the Arnold chord conjecture, Legendrian interlinking, the existence of time-functions and the study of metrics due to Hofer-Chekanov-Shelukhin, Colin-Sandon, Fraser-Polterovich-Rosen and Nakamura.