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A generalized moment map is proposed for arbitrary symplectic actions of compact connected Lie groups on closed symplectic manifolds, in the spirit of the circle -valued maps introduced by D. McDuff in the case of non-Hamiltonian circle…

Symplectic Geometry · Mathematics 2016-09-07 Pierre Sleewaegen

We show that a small neighborhood of a closed symplectic submanifold in a geometrically bounded aspherical symplectic manifold has non-vanishing symplectic homology. As a consequence, we establish the existence of contractible closed…

Differential Geometry · Mathematics 2007-05-23 Kai Cieliebak , Viktor L. Ginzburg , Ely Kerman

Consider a compact symplectic manifold of dimension $2n$ with a Hamiltionan circle action. Then there are at least $n+1$ fixed points. Motivated by recent works on the case that the fixed point set consists of precisely $n+1$ isolated…

Symplectic Geometry · Mathematics 2025-03-10 Hui Li

The group $Ham(M,\omega)$ of all Hamiltonian diffeomorphisms of a symplectic manifold $(M,\omega)$ plays a central role in symplectic geometry. This group is endowed with the Hofer metric. In this paper we study two aspects of the geometry…

Symplectic Geometry · Mathematics 2020-12-17 Arnon Chor

We compute the mapping class group orbits in the homotopy set of framings of a compact connected oriented surface with non-empty boundary. In the case $g > 1$ the computation is some modification of Johnson's results and certain arguments…

Geometric Topology · Mathematics 2017-03-30 Nariya Kawazumi

Classical and quantum Hamiltonian reductions of free geodesic systems of complete Riemannian manifolds are investigated. The reduced systems are described under the assumption that the underlying compact symmetry group acts in a polar…

Mathematical Physics · Physics 2009-11-13 L. Feher , B. G. Pusztai

Consider a Hamiltonian action of a compact connected Lie group on a conformal symplectic manifold. We prove a convexity theorem for the moment map under the assumption that the action is of Lee type, which establishes an analog of Kirwan's…

Symplectic Geometry · Mathematics 2023-11-27 Youming Chen , Reyer Sjamaar , Xiangdong Yang

Let (M,\omega) be a four dimensional compact connected symplectic manifold. We prove that (M,\omega) admits only finitely many inequivalent Hamiltonian effective 2-torus actions. Consequently, if M is simply connected, the number of…

Symplectic Geometry · Mathematics 2011-04-26 Yael Karshon , Liat Kessler , Martin Pinsonnault

We consider the symplectic vortex equations for a linear Hamiltonian torus action. We show that the associated genus zero moduli space itself is homotopic (in the sense of a homotopy of regular G-moduli problems) to a toric manifold with…

Symplectic Geometry · Mathematics 2008-12-02 Jan Wehrheim

We study the dynamics and symplectic topology of energy hypersurfaces of mechanical Hamiltonians on twisted cotangent bundles. We pay particular attention to periodic orbits, displaceability, stability and the contact type property, and the…

Symplectic Geometry · Mathematics 2014-11-11 K. Cieliebak , U. Frauenfelder , G. P. Paternain

The aim of this paper is to formulate a local systolic inequality for odd-symplectic forms (also known as Hamiltonian structures) and to establish it in some basic cases. Let $\Omega$ be an odd-symplectic form on an oriented closed manifold…

Symplectic Geometry · Mathematics 2019-02-07 Gabriele Benedetti , Jungsoo Kang

Invariants for Riemann surfaces covered by the disc and for hyperbolic manifolds in general involving minimizing the measure of the image over the homotopy and homology classes of closed curves and maps of the $k$-sphere into the manifold…

Complex Variables · Mathematics 2022-06-17 Robert E. Greene , Kang-Tae Kim , Nikolay V. Shcherbina

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

For an aspherical symplectic manifold, closed or with convex contact boundary, and with vanishing first Chern class, a Floer chain complex is defined for Hamiltonians linear at infinity with coefficients in the group ring of the fundamental…

Symplectic Geometry · Mathematics 2021-10-22 Sebastian Pöder Balkeståhl

We present some methods to construct smooth circle actions on symplectic manifolds with non-symplectic fixed point sets or non-symplectic cyclic isotropy point sets. All such actions are not compatible with any symplectic form.

Symplectic Geometry · Mathematics 2010-01-06 Boguslaw Hajduk , Krzysztof Pawalowski , Aleksy Tralle

In the early $1980$s a landmark result was obtained by Atiyah and independently Guillemin and Sternberg: the image of the momentum map for a torus action on a compact symplectic manifold is a convex polyhedron. Atiyah's proof makes use of…

Symplectic Geometry · Mathematics 2014-07-17 Kathleen Smith

Let L->M be a Hermitian line bundle over a compact manifold. Write S for the space of all unitary connections in L whose curvatures define symplectic forms on M and G for the group of unitary bundle isometries of L, which acts on S by…

Symplectic Geometry · Mathematics 2017-03-24 Joel Fine

We introduce topological contact dynamics of a smooth manifold carrying a cooriented contact structure, generalizing previous work in the case of a symplectic structure [MO07] or a contact form [BS12]. A topological contact isotopy is not…

Symplectic Geometry · Mathematics 2013-10-07 Stefan Müller , Peter Spaeth

We propose a novel approach to contact Hamiltonian mechanics which, in contrast to the one dominating in the literature, serves also for non-trivial contact structures. In this approach Hamiltonians are no longer functions on the contact…

Symplectic Geometry · Mathematics 2022-11-03 Katarzyna Grabowska , Janusz Grabowski

Various Hamiltonian actions of loop groups $\wt G$ and of the algebra $\text{diff}_1$ of first order differential operators in one variable are defined on the cotangent bundle $T^*\wt G$ of a Loop Group. The moment maps generating the…

High Energy Physics - Theory · Physics 2014-10-07 John Harnad , B. A. Kupershmidt