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Related papers: Convexity of multi-valued momentum map

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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

The convexity theorem of Atiyah and Guillemin-Sternberg says that any connected compact manifold with Hamiltonian torus action has a moment map whose image is the convex hull of the image of the fixed point set. Sjamaar-Lerman proved that…

Differential Geometry · Mathematics 2007-05-23 Bong H. Lian , Bailin Song

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

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

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

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

Let $(M,\omega)$ be a closed $2n$-dimensional symplectic manifold equipped with a Hamiltonian $T^{n-1}$-action. Then Atiyah-Guillemin-Sternberg convexity theorem implies that the image of the moment map is an $(n-1)$-dimensional convex…

Symplectic Geometry · Mathematics 2016-01-05 Yunhyung Cho , Min Kyu Kim

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

The main result of this paper is a quasi-hamiltonian analogue of a special case of the O'Shea-Sjamaar convexity theorem for usual momentum maps. We denote by U a simply connected compact connected Lie group and we fix an involutive…

Symplectic Geometry · Mathematics 2007-05-23 Florent Schaffhauser

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 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 study generalized moment maps for a Hamiltonian action on a connected compact $H$-twisted generalized complex manifold introduced by Lin and Tolman and prove the convexity and connectedness properties of the generalized moment maps for a…

Differential Geometry · Mathematics 2007-10-23 Yasufumi Nitta

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

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

Atiyah's formulation of what is nowadays called the convexity theorem of Atiyah-Guillemin-Sternberg has two parts: (a) the image of the moment map arising from a Hamiltonian action of a torus on a symplectic manifold is a convex polytope,…

Differential Geometry · Mathematics 2007-05-23 Augustin-Liviu Mare

We show that the cone associated with a moment map for an action of a torus on a contact compact connected manifold is a convex polyhedral cone and that the moment map has connected fibers provided the dimension of the torus is bigger than…

Symplectic Geometry · Mathematics 2007-05-23 Eugene Lerman

In this note, we state and give the main ideas of the proof of a real convexity theorem for group-valued momentum maps. This result is a quasi-Hamiltonian analogue of the O'Shea-Sjamaar theorem in the usual Hamiltonian setting. We prove…

Symplectic Geometry · Mathematics 2009-06-15 Florent Schaffhauser

In this paper we show that the transverse image of the momentum map of a Hamiltonian Lie group action admits a natural integral affine stratification with the property that over each stratum the momentum map is an equivariantly locally…

Symplectic Geometry · Mathematics 2025-09-01 Maarten Mol

Let M be a compact, connected symplectic 2n-dimensional manifold on which an(n-2)-dimensional torus T acts effectively and Hamiltonianly. Under the assumption that there is an effective complementary 2-torus acting on M with symplectic…

Symplectic Geometry · Mathematics 2012-07-06 Yi Lin , Álvaro Pelayo

The main result of this paper is a convexity theorem for momentum mappings of certain hamiltonian actions of noncompact semisimple Lie groups. The image is required to fall within a certain open subset D of the (dual of the) Lie algebra,…

Symplectic Geometry · Mathematics 2007-05-23 Alan Weinstein
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