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Related papers: Unimodular Sasaki and Vaisman Lie groups

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A Vaisman manifold is a special kind of locally conformally Kaehler manifold, which is closely related to a Sasaki manifold. In this paper we show a basic structure theorem of simply connected homogeneous Sasaki and Vaisman manifods of…

Differential Geometry · Mathematics 2020-04-08 Dmitry Alekseevsky , Keizo Hasegawa , Yoshinobu Kamishima

We prove various classification results for homogeneous locally conformally symplectic manifolds. In particular, we show that a homogeneous locally conformally Kaehler manifold of a reductive group is of Vaisman type, if the normalizer of…

Differential Geometry · Mathematics 2016-01-15 Dmitri V. Alekseevsky , Vicente Cortes , Keizo Hasegawa , Yoshinobu Kamishima

We define reduction of locally conformal Kaehler manifolds, considered as conformal Hermitian manifolds, and we show its equivalence with an unpublished construction given by Biquard and Gauduchon. We show the compatibility between this…

Differential Geometry · Mathematics 2007-05-23 Rosa Gini , Liviu Ornea , Maurizio Parton

We study left-invariant locally conformally K\"ahler structures on Lie groups, or equivalently, on Lie algebras. We give some properties of these structures in general, and then we consider the special cases when its complex structure is…

Differential Geometry · Mathematics 2020-04-06 Adrián Andrada , Marcos Origlia

We characterize unimodular solvable Lie algebras with Vaisman structures in terms of K\"ahler flat Lie algebras equipped with a suitable derivation. Using this characterization we obtain algebraic restrictions for the existence of Vaisman…

Differential Geometry · Mathematics 2020-04-06 Adrián Andrada , Marcos Origlia

Sasakian manifolds are odd-dimensional counterpart to Kahler manifolds. They can be defined as contact manifolds equipped with an invariant Kahler structure on their symplectic cone. The quotient of this cone by the homothety action is a…

Differential Geometry · Mathematics 2024-05-24 Liviu Ornea , Misha Verbitsky

The Hessian geometry is the real analogue of the K\"ahler one. Sasakian geometry is an odd-dimensional counterpart of the K\"ahler geometry. In the paper, we study the connection between projective Hessian and Sasakian manifolds analogous…

Differential Geometry · Mathematics 2019-10-11 Pavel Osipov

We study homogeneous metric spaces, by which we mean connected, locally compact metric spaces whose isometry group acts transitively. After a review of some classical results, we use the Gleason-Iwasawa-Montgomery-Yamabe-Zippin structure…

Let $G/H$ be a contractible homogeneous Sasaki manifold. A compact locally homogeneous aspherical Sasaki manifold $\Gamma\big\backslash G/H$ is by definition a quotient of $G/H$ by a discrete uniform subgroup $\Gamma\leq G$. We show that a…

Differential Geometry · Mathematics 2020-04-21 Oliver Baues , Yoshinobu Kamishima

In this paper we show as main results two structure theorems of a compact homogeneous locally conformally Kaehler (or shortly l.c.K.) manifold, a holomorphic structure theorem asserting that it has a structure of holomorphic principal fiber…

Complex Variables · Mathematics 2016-01-19 Keizo Hasegawa , Yoshinobu Kamishima

We study the Lie algebra of infinitesimal isometries on compact Sasakian and K--contact manifolds. On a Sasakian manifold which is not a space form or 3--Sasakian, every Killing vector field is an infinitesimal automorphism of the Sasakian…

Differential Geometry · Mathematics 2019-01-08 Florin Belgun , Andrei Moroianu , Uwe Semmelmann

We obtain an exhaustive classification of totally umbilical surfaces in unimodular and non-unimodular simply-connected 3-dimensional Lie groups endowed with arbitrary left-invariant Riemannian metrics. This completes the classification of…

Differential Geometry · Mathematics 2015-03-02 José M. Manzano , Rabah Souam

We obtain some general results on Sasakian Lie algebras and prove as a consequence that a (2n + 1)-dimensional nilpotent Lie group admitting left-invariant Sasakian structures is isomorphic to the real Heisenberg group $H_{2n + 1}$.…

Differential Geometry · Mathematics 2009-03-12 Adrian Andrada , Anna Fino , Luigi Vezzoni

In this paper, we discuss several relations between the existence of invariant volume forms for Hamiltonian systems on Poisson-Lie groups and the unimodularity of the Poisson-Lie structure. In particular, we prove that Hamiltonian vector…

Differential Geometry · Mathematics 2023-01-11 I. Gutierrez-Sagredo , D. Iglesias Ponte , J. C. Marrero , E. Padrón , Z. Ravanpak

Suppose $G$ is a connected complex Lie group and $H$ is a closed complex subgroup such that $X := G/H$ is Kaehler and the codimension of the top non-vanishing homology group of $X$ with coefficients in $\mathbb Z_2$ is less than or equal to…

Complex Variables · Mathematics 2016-12-30 Seyed Ruhallah Ahmadi , Bruce Gilligan

For each left-invariant Riemannian metric on simply connected nonunimodular Lie groups of dimension four, we determine the full group of isometries.

Differential Geometry · Mathematics 2025-05-22 Youssef Ayad

We describe the full group of isometries of each left invariant Riemannian metric on the simply connected unimodular nilpotent or solvable $(R)$-type Lie groups of dimension four.

Differential Geometry · Mathematics 2024-12-03 Youssef Ayad , Said Fahlaoui

We describe the full group of isometries of absolutely simple, compact, connected real Lie groups, of SO(4) and of U(n), endowed with suitable bi-invariant Riemannian metrics.

Differential Geometry · Mathematics 2021-06-14 Alberto Dolcetti , Donato Pertici

Classification results are given for (i) compact quaternionic K\"ahler manifolds with a cohomogeneity-one action of a semi-simple group, (ii) certain complete hyperK\"ahler manifolds with a cohomogeneity-two action of a semi-simple group…

Differential Geometry · Mathematics 2007-05-23 Andrew Dancer , Andrew Swann

It is known that automorphism group $G$ of a compact homogeneous locally conformally K\"ahler manifold $M=G/H$ has at least a 1-dimensional center. We prove that the center of $G$ is at most 2-dimensional, and that if its dimension is 2,…

Differential Geometry · Mathematics 2013-11-05 Andrei Moroianu , Liviu Ornea
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