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Related papers: Hofer's diameter and Lagrangian intersections

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The present paper considers Hofer's distance between diameters in the unit disk. We prove that this distance is unbounded and show its relation to Lagrangian intersections.

Symplectic Geometry · Mathematics 2021-06-15 M. Khanevsky

We resolve three longstanding questions related to the large scale geometry of the group of Hamiltonian diffeomorphisms of the two-sphere, equipped with Hofer's metric. Namely: (1) we resolve the Kapovich-Polterovich question by showing…

Symplectic Geometry · Mathematics 2021-12-07 Dan Cristofaro-Gardiner , Vincent Humilière , Sobhan Seyfaddini

The diameter of the spectral pseudometric on the universal cover of the Hamiltonian diffeomorphism group of $\mathrm{Gr}(2,p)$ is shown to be finite whenever $p$ is a prime number. On the other hand, it is shown that the diameter is…

Symplectic Geometry · Mathematics 2025-12-24 Habib Alizadeh , Marcelo S. Atallah , Dylan Cant , Jianqiao Shang

We show that for each $p \geq 1,$ the $L^p$-metric on the group of area-preserving diffeomorphisms of the two-sphere has infinite diameter. This solves the last open case of a conjecture of Shnirelman from 1985. Our methods extend to yield…

Geometric Topology · Mathematics 2018-03-16 Michael Brandenbursky , Egor Shelukhin

For a class of Riemannian manifolds that include products of arbitrary compact manifolds with manifolds of nonpositive sectional curvature on the one hand, or with certain positive-curvature examples such as spheres of dimension at least 3…

Symplectic Geometry · Mathematics 2014-09-10 Michael Usher

We study configurations of disjoint Lagrangian submanifolds in certain low-dimensional symplectic manifolds from the perspective of the geometry of Hamiltonian maps. We detect infinite-dimensional flats in the Hamiltonian group of the…

Symplectic Geometry · Mathematics 2023-02-07 Leonid Polterovich , Egor Shelukhin

We construct a new infinite-dimensional family of homogeneous quasimorphisms on the group of Hamiltonian diffeomorphisms of the two-sphere. Moreover, for any constant $K$ less than the total area of the sphere, we produce unbounded…

Symplectic Geometry · Mathematics 2025-12-01 Yongsheng Jia , Richard Webb

We construct an example of a non-trivial homogeneous quasimorphism on the group of Hamiltonian diffeomorphisms of the two and four dimensional quadric hypersurfaces which is continuous with respect to both the $C^0$-metric and the Hofer…

Symplectic Geometry · Mathematics 2022-03-03 Yusuke Kawamoto

We show that the $L^{\infty}$-norm of the contact Hamiltonian induces a non-degenerate right-invariant metric on the group of contactomorphisms of any closed contact manifold. This contact Hofer metric is not left-invariant, but rather…

Symplectic Geometry · Mathematics 2015-10-22 Egor Shelukhin

In this paper, we construct infinitely many bi-invariant metrics on the Hamiltonian diffeomorphism group and study their basic properties and corresponding generalizations of the Hofer inequality and Sikorav one.

Symplectic Geometry · Mathematics 2014-06-24 Guangcun Lu , Tie Sun

We compare Hofer's geometries on two spaces associated with a closed symplectic manifold M. The first space is the group of Hamiltonian diffeomorphisms. The second space L consists of all Lagrangian submanifolds of $M \times M$ which are…

Symplectic Geometry · Mathematics 2007-05-23 Yaron Ostrover

We argue that an infinite circumference limit can be obtained in 2-dimensional conformal field theory by adopting $L_0-(L_1+L_{-1})/2$ as a Hamiltonian instead of $L_0$. The theory obtained has a circumference of infinite length and hence…

High Energy Physics - Theory · Physics 2015-07-20 Nobuyuki Ishibashi , Tsukasa Tada

We show that if (M,\omega) is a closed symplectic manifold which admits a nontrivial Hamiltonian vector field all of whose contractible closed orbits are constant, then Hofer's metric on the group of Hamiltonian diffeomorphisms of…

Symplectic Geometry · Mathematics 2014-09-10 Michael Usher

We show that the set of Hamiltonian isotopies of certain unions of circles inside the disc is unbounded for the Hofer distance. The proof relies on a result by Francesco Morabito together with a standard argument of Michael Khanevsky.

Symplectic Geometry · Mathematics 2024-10-15 Ibrahim Trifa

We use spectral invariants in Lagrangian Floer theory in order to show that there exist \emph{isometric} embeddings of normed linear spaces (finite or infinite dimensional, depending on the case) into the space of Hamiltonian deformations…

Symplectic Geometry · Mathematics 2012-01-04 Frol Zapolsky

We prove that the autonomous norm on the group of Hamiltonian diffeomorphisms of the two-dimensional torus is unbounded. We provide explicit examples of Hamiltonian diffeomorphisms with arbitrarily large autonomous norm. For the proofs we…

Symplectic Geometry · Mathematics 2016-02-16 Michael Brandenbursky , Jarek Kedra , Egor Shelukhin

We study the existence or not of harmonic diffeomorphisms between certain domains in the Euclidean 2-sphere. In particular, we show harmonic diffeomorphisms from circular domains in the complex plane onto finitely punctured spheres, with at…

Differential Geometry · Mathematics 2011-10-04 Antonio Alarcon , Rabah Souam

The group $\text{Diff}(\mathcal{M})$ of diffeomorphisms of a closed manifold $\mathcal{M}$ is naturally equipped with various right-invariant Sobolev norms $W^{s,p}$. Recent work showed that for sufficiently weak norms, the geodesic…

Differential Geometry · Mathematics 2021-02-12 Martin Bauer , Cy Maor

We show, by an elementary and explicit construction, that the group of Hamiltonian diffeomorphisms of certain symplectic manifolds, endowed with Hofer's metric, contains subgroups quasi-isometric to Euclidean spaces of arbitrary dimension.

Differential Geometry · Mathematics 2008-09-09 Pierre Py

We find lower bounds on the number of intersection points between two relatively exact Hamiltonian isotopic Lagrangians. The bounds are given in terms of the cuplength of the Lagrangian in various multiplicative generalised cohomology…

Symplectic Geometry · Mathematics 2024-05-01 Amanda Hirschi , Noah Porcelli
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