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Related papers: Quelques plats pour la m\'etrique de Hofer

200 papers

I show that one can explicitly construct topologically/geometrically distinguishable data which provide isomorphic copies (i.e. \emph{isomorphs}) of the tempered fundamental group of a geometrically connected, smooth, quasi-projective…

Algebraic Geometry · Mathematics 2023-03-21 Kirti Joshi

Given a closed symplectic manifold $(M,\omega)$ we introduce a certain quantity associated to a tuple of conjugacy classes in the universal cover of the group ${\hbox{\it Ham}} (M,\omega)$ by means of the Hofer metric on ${\hbox{\it Ham}}…

Symplectic Geometry · Mathematics 2009-10-31 Michael Entov

On any closed symplectic manifold we construct a path-connected neighborhood of the identity in the Hamiltonian diffeomorphism group with the property that each Hamiltonian diffeomorphism in this neighborhood admits a Hofer and spectral…

Symplectic Geometry · Mathematics 2011-08-02 Peter Spaeth

Let $(M,g)$ be a $C^\infty$-smooth, $n$-dimensional Riemannian manifold which is diffeomorphic to $\RR^n$ and admit an action of a properly discontinuous and cocompact group. This work proves the existence of a $C^\infty$ equivariant…

Differential Geometry · Mathematics 2025-11-25 Hongda Qiu

The main theorem of this paper asserts that the inclusion of the space of projective Lagrangian planes into the space of Lagrangian submanifolds of complex projective space induces an injective homomorphism of fundamental groups. We…

Symplectic Geometry · Mathematics 2007-05-23 Meike Akveld , Dietmar Salamon

In this article we study isometric immersions of nearly K\"ahler manifolds into a space form (specially Euclidean space) and show that every nearly K\"ahler submanifold of a space form has a totally umbilic foliation whose leafs are…

Differential Geometry · Mathematics 2014-11-18 Nikrooz Heidari , Abbas Heydari

In this note we present a complete proof of the fact that all the submanifolds of a one parameter family of compact symplectic submanifolds inside a compact symplectic manifold are Hamiltonian isotopic.

Symplectic Geometry · Mathematics 2023-07-14 Paolo Antonini , Fabio Cavalletti , Antonio Lerario

Let $\Sigma$ be a compact surface equipped with an area form. There is an long standing open question by Katok, which, in particular, asks whether every entropy-zero Hamiltonian diffeomorphism of a surface lies in the $C^0$-closure of the…

Symplectic Geometry · Mathematics 2022-05-10 Michael Khanevsky

We establish a cosymplectic counterpart of Banyaga's theorem by proving that the group of weakly Hamiltonian diffeomorphisms, $\Ham_{\eta,\omega}(M)$, is simple on any closed cosymplectic manifold. A key structural result, derived from Lie…

Symplectic Geometry · Mathematics 2025-11-11 S. Tchuiaga , P. Bikorimana

We prove that when Hodge theory survives on non-compact symplectic manifolds, a compact symplectic Lie group action having fixed points is necessarily Hamiltonian, provided the associated almost complex structure preserves the space of…

Symplectic Geometry · Mathematics 2015-03-17 Alvaro Pelayo , Tudor S. Ratiu

In this paper we describe a method to establish when a symplectic manifold $M$ with semi-free Hamiltonian $S^{1}$-action is unique up to isomorphism (equivariant symplectomorphism). This will rely on a study of the symplectic topology of…

Symplectic Geometry · Mathematics 2010-05-11 Eduardo Gonzalez

The main theme of this paper is a relative version of the almost existence theorem for periodic orbits of autonomous Hamiltonian systems. We show that almost all low levels of a function on a geometrically bounded symplectically aspherical…

Differential Geometry · Mathematics 2007-05-23 Viktor L. Ginzburg , Basak Z. Gurel

We prove that the Seidel morphism of $(M \times M', \omega \oplus \omega')$ is naturally related to the Seidel morphisms of $(M,\omega)$ and $(M',\omega')$, when these manifolds are monotone. We deduce that any homotopy class of loops of…

Symplectic Geometry · Mathematics 2009-10-29 Rémi Leclercq

We explicitly construct a symplectomorphism that relates magnetic twists to the invariant hyperk\"ahler structure of the tangent bundle of a Hermitian symmetric space. This symplectomorphism reveals foliations by (pseudo-) holomorphic…

Symplectic Geometry · Mathematics 2024-06-25 Johanna Bimmermann

We show that commutators of Hamiltonian diffeomorphisms may have arbitrarily large Hofer norm. The proposed technique is applicable to positive genus surfaces and their products. This gives partial answer to a question by McDuff and…

Symplectic Geometry · Mathematics 2021-06-15 Michael Khanevsky

The rank of a hierarchically hyperbolic space is the maximal number of unbounded factors in a standard product region. For hierarchically hyperbolic groups, this coincides with the maximal dimension of a quasiflat. Examples for which the…

Geometric Topology · Mathematics 2020-08-25 Jason Behrstock , Mark F Hagen , Alessandro Sisto

Let $G$ be a compact connected semisimple Lie group. We extend the techniques of Weinstein [W] to give a construction in group cohomology of symplectic forms $\omega$ on \lq twisted' moduli spaces of representations of the fundamental group…

alg-geom · Mathematics 2008-02-03 Lisa C. Jeffrey

This is a survey about certain "almost homomorphisms" and "almost linear" functionals (called quasi-morphisms and quasi-states) in symplectic topology and their applications to Hamiltonian dynamics, functional-theoretic properties of…

Symplectic Geometry · Mathematics 2014-12-24 Michael Entov

On an open, connected symplectic manifold $(M,\omega)$, the group of Hamiltonian diffeomorphisms forms an infinite-dimensional Fr\'echet Lie group with Lie algebra $C^{\infty}_c(M)$ and adjoint action given by pullbacks. We prove that this…

Symplectic Geometry · Mathematics 2025-10-31 Lev Buhovsky , Maksim Stokić

We prove that any diffeomorphism of a compact manifold can be approximated in topology C1 by another diffeomorphism exhibiting a homoclinic bifurcation (a homoclinic tangency or a heterodimensional cycle) or by one which is essentially…

Dynamical Systems · Mathematics 2010-11-18 Sylvain Crovisier , Enrique R. Pujals