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Related papers: Convexity properties of presymplectic moment maps

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We generalize symplectic convexity theorems for Hamiltonian actions with proper momentum maps to symplectic actions on orbifolds with mod-$\Gamma$ proper momentum maps.

Symplectic Geometry · Mathematics 2007-05-23 Yang Qilin

We prove a convexity theorem for the image of the moment map of a Hamiltonian torus action on a $b^m$-symplectic manifold.

Symplectic Geometry · Mathematics 2019-04-09 Victor Guillemin , Eva Miranda , Jonathan Weitsman

We introduce the notion of a weak (homotopy) moment map associated to a Lie group action on a multisymplectic manifold. We show that the existence/uniqueness theory governing these maps is a direct generalization from symplectic geometry.…

Symplectic Geometry · Mathematics 2018-07-05 Jonathan Herman

In [GMPS] we proved that the moment map image of a $b$-symplectic toric manifold is a convex $b$-polytope. In this paper we obtain convexity results for the more general case of non-toric hamiltonian torus actions on $b$-symplectic…

Symplectic Geometry · Mathematics 2018-02-13 Victor Guillemin , Eva Miranda , Ana Rita Pires , Geoffrey Scott

In this paper, we consider generalized moment maps for Hamiltonian actions on $H$-twisted generalized complex manifolds introduced by Lin and Tolman \cite{Lin}. The main purpose of this paper is to show convexity and connectedness…

Differential Geometry · Mathematics 2009-01-06 Yasufumi Nitta

We obtain a correspondence between the group of symplectic diffeomorphisms of a 4-dimensional real torus and the vanishing locus of a certain hyperK\"ahler moment map. This observation gives rise to a new flow, called the modified moment…

Symplectic Geometry · Mathematics 2024-03-21 Yann Rollin

We consider a Hamiltonian torus action on a compact connected symplectic manifold M. For a certain class of Lagrangian submanifolds Q of M we show that the image of Q under the momentum map is convex. As an application we complete the…

Symplectic Geometry · Mathematics 2007-05-23 Bernhard Kroetz , Michael Otto

We prove several versions of "quantization commutes with reduction" for circle actions on manifolds that are not symplectic. Instead, these manifolds possess a weaker structure, such as a spin^c structure. Our theorems work whenever the…

dg-ga · Mathematics 2008-02-03 Ana Canas da Silva , Yael Karshon , Susan Tolman

In this paper we extend the results of Kirwan et alii on convexity properties of the moment map for Hamiltonian group actions, and on the connectedness of the fibers of the moment map, to the case of non-compact orbifolds. Our motivation is…

dg-ga · Mathematics 2016-08-31 Eugene Lerman , Eckhard Meinrenken , Sue Tolman , Chris Woodward

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

We consider a connected symplectic manifold $M$ acted on by a connected Lie group $G$ in a Hamiltonian fashion. If $G$ is compact, we prove give an Equivalence Theorem for the symplectic manifolds whose squared moment map $\parallel \mu…

Differential Geometry · Mathematics 2007-05-23 Leonardo Biliotti

Multisymplectic geometry admits an operation that has no counterpart in symplectic geometry, namely, taking the product of two multisymplectic manifolds endowed with the wedge product of the multisymplectic forms. We show that there is an…

Differential Geometry · Mathematics 2016-11-30 C. S. Shahbazi , Marco Zambon

We survey the progress on the study of symplectic geometry past five decades. The survey focuses on the convexity properties of a moment map, the classification of symplectic actions, the symplectic embedding problems, and the theory of…

Symplectic Geometry · Mathematics 2025-10-14 Jae-Hyun Yang

We investigate special lcs and twisted Hamiltonian torus actions on strict lcs manifolds and characterize them geometrically in terms of the minimal presentation. We prove a convexity theorem for the corresponding twisted moment map,…

Differential Geometry · Mathematics 2018-12-05 Florin Belgun , Oliver Goertsches , David Petrecca

We show that contact reductions can be described in terms of symplectic reductions in the traditional Marsden-Weinstein-Meyer as well as the constant rank picture. The point is that we view contact structures as particular (homogeneous)…

Symplectic Geometry · Mathematics 2025-05-12 Katarzyna Grabowska , Janusz Grabowski

Consider a Hamiltonian action of a compact Lie group on a compact symplectic manifold. A theorem of Kirwan's says that the image of the momentum mapping intersects the positive Weyl chamber in a convex polytope. I present a new proof of…

dg-ga · Mathematics 2008-02-03 Reyer Sjamaar

Let K be a connected Lie group and M a Hamiltonian K-manifold. In this paper, we introduce the notion of convexity of M. It implies that the momentum image is convex, the moment map has connected fibers, and the total moment map is open…

Symplectic Geometry · Mathematics 2007-05-23 Friedrich Knop

We study deformations of symplectic structures on a smooth manifold $M$ via the quasi-Poisson theory. By a fact, we can deform a given symplectic structure $\omega $ to a new symplectic structure $\omega_t$ parametrized by some element $t$…

Differential Geometry · Mathematics 2016-05-10 Tomoya Nakamura

We extend the famous convexity theorem of Atiyah, Guillemin and Sternberg to the case of non-Hamiltonian actions. We show that the image of a generalized momentum map is a bounded polytope times a vector space. We prove that this picture is…

Symplectic Geometry · Mathematics 2007-05-23 Andrea Giacobbe

Every action on a Poisson manifold by Poisson diffeomorphisms lifts to a Hamiltonian action on its symplectic groupoid which has a canonically defined momentum map. We study various properties of this momentum map as well as its use in…

Symplectic Geometry · Mathematics 2009-03-02 Rui Loja Fernandes , Juan-Pablo Ortega , Tudor S. Ratiu
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