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Related papers: Contact Reduction

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For contact manifolds $(M, \eta)$ a complexification $M^c$ is constructed to which the contact form $\eta$ extends such that the exterior derivative of the extended form is K\"ahlerian. In the case of a proper action of an extendable Lie…

Complex Variables · Mathematics 2010-06-08 Ayse Kurtdere

Let $(M,\omega)$ be a Hamiltonian $G$-space with a momentum map $F:M \to {\frak g}^*$. It is well-known that if $\alpha$ is a regular value of $F$ and $G$ acts freely and properly on the level set $F^{-1}(G\cdot \alpha)$, then the reduced…

dg-ga · Mathematics 2008-02-03 L. Bates , E. Lerman

Let X be a complex-projective contact manifold whose second Betti-number is one. It has long been conjectured that X should then be rational-homogeneous, or equivalently, that there exists an embedding of X into a projective space whose…

Algebraic Geometry · Mathematics 2007-05-23 Stefan Kebekus

The notion of non-projectible contact forms on a given compact manifold $M$ is introduced by the first-named author in [Ohb], the set of which he also shows is a residual subset of the set of (coorientable) contact forms, both in the case…

Symplectic Geometry · Mathematics 2025-05-13 Yong-Geun Oh , Yasha Savelyev

This thesis focuses on developing "stacky" versions of contact structures, extending the classical notion of contact structures on manifolds. A fruitful approach is to study contact structures using line bundle-valued $1$-forms.…

Differential Geometry · Mathematics 2025-04-01 Antonio Maglio

Cartan's method of moving frames is briefly recalled in the context of immersed curves in the homogeneous space of a Lie group $G$. The contact geometry of curves in low dimensional equi-affine geometry is then made explicit. This delivers…

Differential Geometry · Mathematics 2009-10-20 Peter J. Vassiliou

We investigate the correspondence between the geometry of a smooth compact Lie group action on a manifold $\mathrm{M}$ and the intrinsic smooth structure of the orbit space $\mathrm{M}/\mathrm{G}$. While the action on $\mathrm{M}$ is…

Differential Geometry · Mathematics 2025-08-26 Serap Gürer , Patrick Iglesias-Zemmour

The purpose of this paper is to investigate the definition of symplectic structure on a smooth stratified pseudomanifold in the framework of local $\C^{\infty}$-ringed space theory. We introduce a sheaf-theoretic definition of symplectic…

Symplectic Geometry · Mathematics 2023-09-25 Xiangdong Yang

This is a slightly altered version of the authors thesis from 2014. In the first main part we show that the quotient space of a compact, simply connected and nonnegatively curved Riemannian 4-manifold by an effective, isometric…

Differential Geometry · Mathematics 2015-10-07 Wolfgang Spindeler

Two constructions of contact manifolds are presented: (i) products of S^1 with manifolds admitting a suitable decomposition into two exact symplectic pieces and (ii) fibre connected sums along isotropic circles. Baykur has found a…

Symplectic Geometry · Mathematics 2010-06-22 Hansjörg Geiges , András I. Stipsicz

For a compact Lie group $G$ we consider a lattice gauge model given by the $G$-Hamiltonian system which consists of the cotangent bundle of a power of $G$ with its canonical symplectic structure and standard moment map. We explicitly…

Mathematical Physics · Physics 2020-09-21 Markus J. Pflaum , Gerd Rudolph , Matthias Schmidt

Let $G$ be a semisimple Lie group with finite component group, and let $K<G$ be a maximal compact subgroup. We obtain a quantisation commutes with reduction result for actions by $G$ on manifolds of the form $M = G\times_K N$, where $N$ is…

Symplectic Geometry · Mathematics 2015-04-10 Peter Hochs

In this paper, metric reduction in generalized geometry is investigated. We show how the Bismut connections on the quotient manifold are obtained from those on the original manifold. The result facilitates the analysis of generalized…

Differential Geometry · Mathematics 2018-10-08 Yicao Wang

We prove a reduction theorem for the tangent bundle of a Poisson manifold $(M, \pi)$ endowed with a pre-Hamiltonian action of a Poisson Lie group $(G, \pi_G)$. In the special case of a Hamiltonian action of a Lie group, we are able to…

Differential Geometry · Mathematics 2017-03-24 Antonio De Nicola , Chiara Esposito

The purpose of this note is to exhibit some simple and basic constructions for smooth compact transformation groups, and some of their most immediate applications to geometry.

Differential Geometry · Mathematics 2012-07-19 Karsten Grove , Catherine Searle

In this article, we investigate metric structures on the symplectization of a contact metric manifold and prove that there is a unique metric structure, which we call the metric symplectization, for which each slice of the symplectization…

Differential Geometry · Mathematics 2024-07-23 Sannidhi Alape

Consider a compact prequantizable symplectic manifold M on which a compact Lie group G acts in a Hamiltonian fashion. The ``quantization commutes with reduction'' theorem asserts that the G-invariant part of the equivariant index of M is…

dg-ga · Mathematics 2008-02-03 Eckhard Meinrenken , Reyer Sjamaar

It is well-known that an effective orbifold M (one for which the local stabilizer groups act effectively) can be presented as a quotient of a smooth manifold P by a locally free action of a compact lie group K. We use the language of…

Algebraic Topology · Mathematics 2007-05-23 Andre Henriques , David Metzler

There is a canonical identification, due to the author, of a convex real projective structure on an orientable surface of genus g and a pair consisting of a conformal structure together with a holomorphic cubic differential on the surface.…

Differential Geometry · Mathematics 2007-05-23 John C. Loftin

The main purpose of this article is to classify contact structures on some 3-manifolds, namely lens spaces, most torus bundles over a circle, the solid torus, and the thickened torus T^2 x [0,1]. This classification completes earlier work…

Geometric Topology · Mathematics 2009-10-31 Emmanuel Giroux