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Related papers: Central extensions of groups of symplectomorphisms

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We introduce the notion of \emph{topo-symmetric extensions} of topological groups, a new generalization of classical group extensions that incorporates both topological and symmetry constraints. We define morphisms between such extensions,…

General Mathematics · Mathematics 2025-10-02 Es-said En-naoui

Introducing the notion of stabilized fundamental group for the complement of a branch curve in $CP^2$, we define effectively computable invariants of symplectic 4-manifolds that generalize those previously introduced by Moishezon and…

Geometric Topology · Mathematics 2007-05-23 D. Auroux , S. K. Donaldson , L. Katzarkov , M. Yotov

Let $\mathbb{G}$ be a Lie group with solvable connected component and finitely-generated component group and $\alpha\in H^2(\mathbb{G},\mathbb{S}^1)$ a cohomology class. We prove that if $(\mathbb{G},\alpha)$ is of type I then the same…

Group Theory · Mathematics 2022-09-07 Alexandru Chirvasitu

Torus orbifolds are topological generalization of symplectic toric orbifolds. We give a construction of smooth orbifolds with torus actions whose boundary is a disjoint union of torus orbifolds using toric topological method. As a result,…

Algebraic Topology · Mathematics 2019-05-21 Soumen Sarkar , Dong Youp Suh

A geometrical structure on even-dimensional manifolds is defined which generalizes the notion of a Calabi-Yau manifold and also a symplectic manifold. Such structures are of either odd or even type and can be transformed by the action of…

Differential Geometry · Mathematics 2011-05-05 Nigel Hitchin

The aim of this paper is to study the $(\alpha, \gamma)$-prolongation of central extensions. We obtain the obstruction theory for $(\alpha, \gamma)$-prolongations and classify $(\alpha, \gamma)$-prolongations thanks to low-dimensional…

Group Theory · Mathematics 2013-01-09 Nguyen Tien Quang , Che T. Kim Phung , Pham Thi Cuc

We construct new examples of immersed minimal surfaces with catenoid ends and finite total curvature, of both genus zero and higher genus. In the genus zero case, we classify all such surfaces with at most $2n+1$ ends, and with symmetry…

Differential Geometry · Mathematics 2008-04-29 Wayne Rossman

It was shown by Gersten that a central extension of a finitely generated group is quasi-isometrically trivial provided that its Euler class is bounded. We say that a finitely generated group $G$ satisfies Property QITB (quasi-isometrically…

Group Theory · Mathematics 2022-11-15 Roberto Frigerio , Alessandro Sisto

We examine asymptotic dimension and property A for groups acting on complexes. In particular, we prove that the fundamental group of a finite, developable complex of groups will have finite asymptotic dimension provided the geometric…

Group Theory · Mathematics 2007-05-23 Gregory C. Bell

We characterise the set of fundamental groups for which there exist $n$-manifolds that are $h$-cobordant (hence homotopy equivalent) but not simple homotopy equivalent, when $n$ is sufficiently large. In particular, for $n \ge 12$ even, we…

Geometric Topology · Mathematics 2024-09-06 Csaba Nagy , John Nicholson , Mark Powell

We use differential forms on loop spaces to prove that the fundamental group of certain geometric transformation groups is infinite. Examples include both finite and infinite dimensional Lie groups. The finite dimensional examples are the…

Differential Geometry · Mathematics 2025-10-03 Yoshiaki Maeda , Steven Rosenberg

The mapping class group of a surface with one boundary component admits numerous interesting representations including as a group of automorphisms of a free group and as a group of symplectic transformations. Insofar as the mapping class…

Geometric Topology · Mathematics 2009-06-01 Jorgen Ellegaard Andersen , Alex James Bene , R. C. Penner

We provide examples of contact manifolds of any odd dimension $\geq 5$ which are not diffeomorphic but have exact symplectomorphic symplectizations.

Symplectic Geometry · Mathematics 2015-12-11 Sylvain Courte

The connections between Euler's equations on central extensions of Lie algebras and Euler's equations on the original, extended algebras are described. A special infinite sequence of central extensions of nilpotent Lie algebras constructed…

Differential Geometry · Mathematics 2024-12-03 I. A. Taimanov

This paper is the first part in a 2 part study of an elementary functorial construction from the category of finite non-abelian groups to a category of singular compact, oriented 2-manifolds. After a desingularization process this…

Geometric Topology · Mathematics 2013-10-16 Mark Herman , Jonathan Pakianathan , Ergun Yalcin

The purpose of this note is to verify that the results attained in [6] admit an extension to the multidimensional setting. Namely, for subsets of the two dimensional torus we find the sharp growth rate of the step(s) of a generalized…

Classical Analysis and ODEs · Mathematics 2017-11-13 Itay Londner

We consider isomonodromic deformations of connections with a simple pole on the torus, motivated by the elliptic version of the sixth Painlev\'e equation. We establish an extended symmetry, complementing known results. The Calogero-Moser…

Mathematical Physics · Physics 2024-11-22 Mohamad Alameddine

Given two four-dimensional symplectic manifolds, together with knots in their boundaries, we define an ``anchored symplectic embedding'' to be a symplectic embedding, together with a two-dimensional symplectic cobordism between the knots…

Symplectic Geometry · Mathematics 2025-12-09 Michael Hutchings , Agniva Roy , Morgan Weiler , Yuan Yao

Thurston has claimed (unpublished) that central extensions of word hyperbolic groups by finitely generated abelian groups are automatic. We show that they are in fact biautomatic. Further, we show that every 2-dimensional cohomology class…

Group Theory · Mathematics 2008-02-03 Walter Neumann , Lawrence Reeves

We consider the dimensional reduction on a torus of the family of 6d $(1,0)$ SCFTs UV completing an $so(N)$ gauge theory with $N-8$ vector hypermultiplets. These SCFTs are known to possess a rich structure of discrete symmetries, notably…

High Energy Physics - Theory · Physics 2025-03-04 Gabi Zafrir