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Related papers: Convexity properties of generalized moment maps

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We study the action of Hamiltonian diffeomorphisms of a compact symplectic manifold ($X,\omega$) on $C^\infty(X)$ and on functions $C^\infty(X)\to \mathbb R$. We describe various properties of invariant convex functions on $C^\infty(X)$.…

Symplectic Geometry · Mathematics 2021-01-12 Laszlo Lempert

The main contribution of this manuscript is a local normal form for Hamiltonian actions of Poisson-Lie groups $K$ on a symplectic manifold equipped with an $AN$-valued moment map, where $AN$ is the dual Poisson-Lie group of $K$. Our proof…

Symplectic Geometry · Mathematics 2023-03-08 Megumi Harada , Jeremy Lane , Aidan Patterson

Classically, a single weight on an interval of the real line leads to moments, orthogonal polynomials and tridiagonal matrices. Appropriately deforming this weight with times t=(t_1,t_2,...), leads to the standard Toda lattice and…

Exactly Solvable and Integrable Systems · Physics 2016-09-07 Mark Adler , Pierre van Moerbeke

We investigate the equivariant cohomology of the natural torus action on a K-contact manifold and its relation to the topology of the Reeb flow. Using the contact moment map, we show that the equivariant cohomology of this action is…

Symplectic Geometry · Mathematics 2018-03-16 Oliver Goertsches , Hiraku Nozawa , Dirk Toeben

Let a torus T act effectively on a compact connected cooriented contact manifold, and let Psi be the natural momentum map on the symplectization. We prove that, if dim T > 2, the union of the origin with the image of Psi is a convex…

Symplectic Geometry · Mathematics 2014-10-01 River Chiang , Yael Karshon

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

Karshon constructed the first counterexample to the log-concavity conjecture for the Duistermaat-Heckman measure: a Hamiltonian six manifold whose fixed points set is the disjoint union of two copies of $T^4$. In this article, for any…

Symplectic Geometry · Mathematics 2008-03-03 Yi Lin

We prove that to every connected Abelian subgroup $H$ of the biholomorphisms of the unit ball $\mathbb{B}^n$ we can associate a set of bounded symbols whose corresponding Toeplitz operators generate a commutative $C^*$-algebra on every…

Complex Variables · Mathematics 2020-09-29 Raul Quiroga-Barranco , Armando Sanchez-Nungaray

We study the action of a real reductive group $G$ on a Kahler manifold $Z$ which is the restriction of a holomorphic action of a complex reductive Lie group $U^\mathbb{C}.$ We assume that the action of $U$, a maximal compact connected…

Differential Geometry · Mathematics 2025-03-05 Oluwagbenga Joshua Windare

Using the analytic assembly map that appears in the Baum-Connes conjecture in noncommutative geometry, we generalise the $\Spin^c$-version of the Guillemin-Sternberg conjecture that `quantisation commutes with reduction' to (discrete series…

Symplectic Geometry · Mathematics 2012-06-27 Peter Hochs

We provide a model for an open invariant neighborhood of any orbit in a symplectic manifold endowed with a canonical proper symmetry. Our results generalize the constructions of Marle and Guillemin and Sternberg for canonical symmetries…

Symplectic Geometry · Mathematics 2007-05-23 Juan-Pablo Ortega , Tudor S. Ratiu

Goldman defined a symplectic form on the smooth locus of the $G$-character variety of a closed, oriented surface $S$ for a Lie group $G$ satisfying very general hypotheses. He then studied the Hamiltonian flows associated to $G$-invariant…

Geometric Topology · Mathematics 2024-10-08 Fernando Camacho-Cadena , James Farre , Anna Wienhard

We extend the classical Donaldson-Fujiki interpretation of the scalar curvature as moment map in K\"ahler Geometry to the wider framework of locally conformally K\"ahler Geometry.

Differential Geometry · Mathematics 2023-06-30 Daniele Angella , Simone Calamai , Francesco Pediconi , Cristiano Spotti

With the smooth action of a connected compact Lie group G, we realize the G-invariant Thom-Smale complex in an analytic way using the G-invariant Witten instanton complex. Both complexes are associated to a specific Morse-Bott function on a…

Differential Geometry · Mathematics 2025-01-16 Hao Zhuang

Following Boalch-Yamakawa and Meinrenken, we consider a certain class of moduli spaces on bordered surfaces from a quasi-Hamiltonian perspective. For a given Lie group $G$, these character varieties parametrize flat $G$-connections on…

Differential Geometry · Mathematics 2021-02-03 Ahmed J. Zerouali

This paper presents a study of generalized polyhedral convexity under basic operations on multifunctions. We address the preservation of generalized polyhedral convexity under sums and compositions of multifunctions, the domains and ranges…

Optimization and Control · Mathematics 2023-10-19 Nguyen Ngoc Luan , Nguyen Mau Nam , Nguyen Dong Yen

A generalization of the Dirac's canonical quantization theory for a system with second-class constraints is proposed as the fundamental commutation relations that are constituted by all commutators between positions, momenta and Hamiltonian…

Mathematical Physics · Physics 2014-10-07 D. M. Xun , Q. H. Liu , X. M. Zhu

This is the second of two companion papers. We describe a generalization of the point vortex system on surfaces to a Hamiltonian dynamical system consisting of two or three points on complex projective space CP^2 interacting via a…

Mathematical Physics · Physics 2021-05-18 James Montaldi , Amna Shaddad

A torus manifold is a closed smooth manifold of dimension $2n$ having an effective smooth $T^n = (S^1)^n$-action with non-empty fixed points. Petrie \cite{petrie:1973} has shown that any homotopy equivalence between a complex projective…

Algebraic Topology · Mathematics 2012-09-03 Suyoung Choi

We define the notion of a moment map and reduction in both generalized complex geometry and generalized K\"{a}hler geometry. As an application, we give very simple explicit constructions of bi-Hermitian structures on $\C\P^n$, Hirzebruch…

Differential Geometry · Mathematics 2009-11-11 Yi Lin , Susan Tolman