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This is a collection of notes on the properties of left-invariant metrics on the eight-dimensional compact Lie group SU(3). Among other topics we investigate the existence of invariant pseudo-Riemannian Einstein metrics on this manifold. We…

Differential Geometry · Mathematics 2021-07-27 Robert Coquereaux

This work is devoted to the study of a class of Poisson-Lie groups endowed with left invariant metrics. The triples $(G,\pi,<,>)$ are considered, where $G$ is a simply connected Lie group, ?$\pi$ is a multiplicative Poisson tensor and $<,>$…

Differential Geometry · Mathematics 2011-08-03 Amine bahayou

In this paper, we discuss the decomposition of a Lie group with a left invariant pseudo-Riemannian metric and the uniqueness. In fact, it is a decomposition of a Lie group into totally geodesic sub-manifolds which is different from the De…

Group Theory · Mathematics 2012-03-16 Zhiqi Chen , Ke Liang , Mingming Ren

A Lorentzian flat Lie group is a Lie group $G$ with a flat left invariant metric $\mu$ with signature $(1,n-1)=(-,+,\ldots,+)$. The Lie algebra $\mathfrak{g}=T_eG$ of $G$ endowed with $\langle\;,\;\rangle=\mu(e)$ is called flat Lorentzian…

Differential Geometry · Mathematics 2015-04-21 Mohamed Boucetta , Hicham Lebzioui

In this work we provide a complete characterization of left-invariant symmetric Killing tensors on almost abelian Lie groups endowed with a left-invariant Riemannian metric. We show in particular that all such tensors are decomposable, in…

Differential Geometry · Mathematics 2025-10-01 Renan Berto-Cuevas , Viviana del Barco , Andrei Moroianu

Almost contact structures can be identified with sections of a twistor bundle and this allows to define their harmonicity, as sections or maps. We consider the class of nearly cosymplectic almost contact structures on a Riemannian manifold…

Differential Geometry · Mathematics 2011-09-14 E. Loubeau , E. Vergara-Diaz

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

We study integrability of generalized almost contact structures, and find conditions under which the main associated maximal isotropic vector bundles form Lie bialgebroids. These conditions differentiate the concept of generalized contact…

Differential Geometry · Mathematics 2014-02-26 Yat Sun Poon , Aissa Wade

In this paper we classify all simply connected five dimensional nilpotent Lie groups which admit $(\alpha,\beta)$-metrics of Berwald and Douglas type defined by a left invariant Riemannian metric and a left invariant vector field. During…

Differential Geometry · Mathematics 2024-07-23 Masoumeh Hosseini , Hamid Reza Salimi Moghaddam

In this paper by using left invariant Riemannian metrics on some 3-dimensional Lie groups we construct some complete non-Riemannian Berwald spaces of non-positive flag curvature and several families of geodesically complete locally…

Differential Geometry · Mathematics 2016-12-30 H. R. Salimi Moghaddam

In this paper, we establish a complete structural description of flat Lorentzian Lie groups, i.e., Lie groups endowed with a flat left invariant Lorentzian metric, thereby resolving a long-standing open problem in the theory of…

Differential Geometry · Mathematics 2026-05-12 Mohamed Boucetta

We describe the quasi-isometric classification of fundamental groups of irreducible non-geometric 3-manifolds which do not have "too many" arithmetic hyperbolic geometric components, thus completing the quasi-isometric classification of…

Geometric Topology · Mathematics 2014-07-29 Jason Behrstock , Walter D Neumann

Weak almost contact manifolds, i.e., the linear complex structure on the contact distribution is replaced by a nonsingular skew-symmetric tensor, defined by the author and R. Wolak, allowed us to take a new look at the theory of contact…

Differential Geometry · Mathematics 2024-10-11 Vladimir Rovenski

A new characterization is provided for the class of compact rank-one symmetric spaces. Such spaces are the only symmetric spaces of compact type for which the standard vector field on their sphere bundles is Killing with respect to some…

Differential Geometry · Mathematics 2023-06-21 J. C. González-Dávila

We give a characterization of almost abelian Lie groups carrying left invariant hypercomplex structures and we show that the corresponding Obata connection is always flat. We determine when such Lie groups admit HKT metrics and study the…

Differential Geometry · Mathematics 2023-04-26 Adrián Andrada , María Laura Barberis

A 3-dimensional Riemannian manifold equipped with a tensor structure of type $(1,1)$, whose third power is the identity, is considered. This structure and the metric have circulant matrices with respect to some basis, i.e., these structures…

Differential Geometry · Mathematics 2020-09-22 Iva Dokuzova

We investigate the local geometry of a pair of independent contact structures on 3-manifolds under maps that independently preserve each contact structure. We discover that such maps are homotheties on the contact 1-forms and we discover…

Differential Geometry · Mathematics 2024-05-22 Taylor J. Klotz , George R. Wilkens

In this paper, we study and almost completely classify contact structures on closed 3--manifolds which are totally geodesic for some Riemannian metric. Due to previously known results, this amounts to classifying contact structures on…

Geometric Topology · Mathematics 2014-11-11 Patrick Massot

We study invariant pseudo-K\"ahler structures on a solvmanifold $G$ such that the Lie algebra $\mathfrak{g}$ is almost abelian, that is $\mathfrak{g}=\mathfrak{h}\rtimes\mathbb{R}$, with $\mathfrak{h}$ abelian; comparing with the…

Differential Geometry · Mathematics 2025-06-30 Diego Conti , Alejandro Gil-García

We study left invariant locally conformally product structures on simply connected Lie groups and give their complete description in the solvable unimodular case. Based on previous classification results, we then obtain the complete list of…

Differential Geometry · Mathematics 2024-12-25 Adrián Andrada , Viviana del Barco , Andrei Moroianu