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In this paper, we study the coupled Einstein constraint equations on complete manifolds through the conformal method, focusing on non-compact manifolds with flexible asymptotics. This is physically well-motivated by standard cosmological…

Analysis of PDEs · Mathematics 2026-03-25 Rodrigo Avalos , Jorge Lira , Nicolas Marque

The main purpose of the paper is to prove that if a compact Riemannian manifold admits a gradient $\rho$-Einstein soliton such that the gradient Einstein potential is a non-trivial conformal vector field, then the manifold is isometric to…

Differential Geometry · Mathematics 2018-08-20 Absos Ali Shaikh , Chandan Kumar Mondal

In this paper we use a diffeo-geometric framework based on manifolds that are locally modeled on "convenient" vector spaces to study the geometry of some infinite dimensional spaces. Given a finite dimensional symplectic manifold…

Differential Geometry · Mathematics 2009-11-03 Brian Lee

We prove that the recently shown cohomological obstruction for quasiregular ellipticity has a generalization in the theory of quasiregular values. More specifically, if $M$ is a closed, connected, and oriented Riemannian $n$-manifold, and…

Differential Geometry · Mathematics 2025-11-06 Susanna Heikkilä , Ilmari Kangasniemi

Recent interest among geometers in $f$-structures of K. Yano is due to the study of topology and dynamics of contact foliations, which generalize the flow of the Reeb vector field on contact manifolds to higher dimensions. Weak metric…

Differential Geometry · Mathematics 2025-05-28 Vladimir Rovenski

In the spirit of peripheral subgroups in relatively hyperbolic groups, we exhibit a simple class of quasi-isometrically rigid subgroups in graph products of finite groups, which we call eccentric subgroups. As an application, we prove that,…

Group Theory · Mathematics 2022-08-10 Anthony Genevois

Let $G$ be a non-compact classical semisimple Lie group and let $G/V$ be the adjoint orbit with respect to a fixed element in $G$. These manifolds can be equipped with an almost-K\"ahler structure and we provide explicit formulae for the…

Combinatorics · Mathematics 2022-09-30 Alice Gatti

We explicitly construct several Poisson structures with compact support. For example, we show that any Poisson structure on $\R^n$ with polynomial coefficients of degree at most two can be modified outside an open ball, such that it becomes…

Symplectic Geometry · Mathematics 2022-10-21 Gil R. Cavalcanti , Ioan Marcut

In this article, we investigate certain geometric inequalities on quasi-Einstein manifolds. We use the generalized Reilly's formulas by Qiu-Xia and Li-Xia to establish new boundary estimates and an isoperimetric type inequality for compact…

Differential Geometry · Mathematics 2025-07-01 Rafael Diógenes , Jaciane Gonçalves , Ernani Ribeiro

We call a metric $m$-quasi-Einstein if $Ric_X^m$ (a modification of the $m$-Bakry-Emery Ricci tensor in terms of a suitable vector field $X$) is a constant multiple of the metric tensor. It is a generalization of Einstein metrics which…

Differential Geometry · Mathematics 2015-07-01 Zhiqi Chen , Ke Liang , Fahuai Yi

Let G be a Lie group and g its Lie algebra. We develop a theory of quasi Poisson structures relative to a not necessarily non-degenerate Ad-invariant symmetric 2-tensor in the tensor square of g and one of general not necessarily…

Differential Geometry · Mathematics 2026-01-22 Johannes Huebschmann

We determine the Hamiltonian vector field on an odd dimensional manifold endowed with almost cosymplectic structure. This is a generalization of the corresponding Hamiltonian vector field on manifolds with almost transitive contact…

Differential Geometry · Mathematics 2022-11-23 Stefan Berceanu

This paper focuses on the study of the newly introduced $\ast-\boldsymbol{\kappa}$-Ricci-Bourguignon almost soliton pertaining to Kenmotsu structure manifolds. Our analysis concerns the characteristics of this soliton and derive the scalar…

Differential Geometry · Mathematics 2026-01-21 Lavanya Kumar , Soumendu Roy

A manifold is said to be $n$-plectic if it is equipped with a closed, nondegenerate $(n+1)$-form. This thesis develops the theory of \emph{relative $n$-plectic structures}, where the classical condition is replaced by a closed,…

Symplectic Geometry · Mathematics 2025-09-11 Dinamo Djounvouna

In this paper we prove that under certain conditions in a quasi Einstein semi Riemannian warped product the fiber is necessarily a Einstein manifold. We provide all the quasi Einstein manifolds when r Bakry Emery tensor is null, the base is…

Differential Geometry · Mathematics 2019-05-07 Paula Gonçalves Correia Bonfim , Romildo Pina

We study the large scale geometry of mapping class groups MCG(S), using hyperbolicity properties of curve complexes. We show that any self quasi-isometry of MCG(S) (outside a few sporadic cases) is a bounded distance away from a…

Geometric Topology · Mathematics 2010-04-12 Jason Behrstock , Bruce Kleiner , Yair Minsky , Lee Mosher

A symplectic integration of a Poisson manifold $(M,\Lambda)$ is a symplectic groupoid $(\Gamma,\eta)$ which realizes the given Poisson manifold, i.e. such that the space of units $\Gamma_0$ with the induced Poisson structure $\Lambda_0$ is…

dg-ga · Mathematics 2008-02-03 F. Alcalde-Cuesta , G. Hector

On $4$-symmetric symplectic spaces, invariant almost complex structures -- up to sign -- arise in pairs. We exhibit some $4$-symmetric symplectic spaces, with a pair of "natural" compatible (usually not positive) invariant almost complex…

Differential Geometry · Mathematics 2022-06-14 Michel Cahen , Simone Gutt , Manar Hayyani , Mohammed Raouyane

A locally conformally Kaehler (l.c.K.) manifold is a complex manifold admitting a Kaehler covering $\tilde M$, with each deck transformation acting by Kaehler homotheties. A compact l.c.K. manifold is Vaisman if it admits a holomorphic flow…

Differential Geometry · Mathematics 2019-09-02 Liviu Ornea , Misha Verbitsky

We present a K-theoritic approach to the Guillemin-Sternberg conjecture, about the commutativity of geometric quantization and symplectic reduction, which was proved by Meinrenken and Tian-Zhang. Besides providing a new proof of this…

Differential Geometry · Mathematics 2007-05-23 Paul-Emile Paradan