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Related papers: Graphs and Metric 2-step Nilpotent Lie Algebras

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In this paper, we provide the structure of Hopf graphs associated to pairs $(G, \mathfrak{r})$ consisting of groups $G$ together with ramification datas $\mathfrak{r}$ and their Leavitt path algebras. Consequently, we characterize the…

Rings and Algebras · Mathematics 2023-06-02 T. G. Nam , N. T. Phuc

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

We consider Lie groups equipped with arbitrary distances. We only assume that the distance is left-invariant and induces the manifold topology. For brevity, we call such object metric Lie groups. Apart from Riemannian Lie groups,…

Metric Geometry · Mathematics 2016-02-01 Ville Kivioja , Enrico Le Donne

The index of a Lie algebra is an important invariant which arises in several areas, e.g. in the study of coadjoint orbits for a Lie group, in invariant theory and in representation theory. We study the index for several classes of nilpotent…

Representation Theory · Mathematics 2025-05-14 Dietrich Burde , Karel Dekimpe

We give a geometric classification of complex $n$-dimensional $2$-step nilpotent (all, commutative and anticommutative) algebras. Namely, has been found the number of irreducible components and their dimensions. As a corollary, we have a…

Rings and Algebras · Mathematics 2021-11-02 Mikhail Ignatyev , Ivan Kaygorodov , Yury Popov

We give an algebraic construction of the topological graph-tree configuration pairing of Sinha and Walter beginning with the classical presentation of Lie coalgebras via coefficients of words in the associative Lie polynomial. Our work…

Rings and Algebras · Mathematics 2016-12-30 Ben Walter

For a closed cocompact subgroup $\Gamma$ of a locally compact group $G$, given a compact abelian subgroup $K$ of $G$ and a homomorphism $\rho:\hat{K}\to G$ satisfying certain conditions, Landstad and Raeburn constructed equivariant…

Operator Algebras · Mathematics 2009-09-29 Hanfeng Li

We introduce a directed graph related to a group $G$, which we call the N-prime graph $\Gamma_{\rm{N}}(G)$ of $G$ and which is a refinement of the classical Gruenberg-Kegel graph. The vertices of $\Gamma_{\rm{N}}(G)$ are the primes $p$ such…

Group Theory · Mathematics 2025-11-14 Emanuele Pacifici , Angel del Rio , Marco Vergani

We give a basic treatment of lattices $\Gamma$ in these groups. Certain tori $T_F$ and $T_B$ provide the model fiber and the base for a submersion of $\Gamma\backslash N$. This submersion may not be pseudoriemannian in the usual sense,…

Differential Geometry · Mathematics 2011-05-26 Luis A. Cordero , Phillip E. Parker

We consider seven-dimensional unimodular Lie algebras $\mathfrak{g}$ admitting exact $G_2$-structures, focusing our attention on those with vanishing third Betti number $b_3(\mathfrak{g})$. We discuss some examples, both in the case when…

Differential Geometry · Mathematics 2020-05-28 Marisa Fernández , Anna Fino , Alberto Raffero

We study the relation between two special classes of Riemannian Lie groups $G$ with a left-invariant metric $g$: The Einstein Lie groups, defined by the condition $\operatorname{Ric}_g=cg$, and the geodesic orbit Lie groups, defined by the…

Differential Geometry · Mathematics 2024-01-15 Nikolaos Panagiotis Souris

In this paper we give detailed construction of $G$-equivariant Kuranishi chart of moduli spaces of pseudo-holomorphic curves to a symplectic manifold with $G$-action, for an arbitrary compact Lie group $G$. The proof is based on the…

Symplectic Geometry · Mathematics 2020-07-28 Kenji Fukaya

A Lie 2-group $G$ is a category internal to the category of Lie groups. Consequently it is a monoidal category and a Lie groupoid. The Lie groupoid structure on $G$ gives rise to the Lie 2-algebra $\mathbb{X}(G)$ of multiplicative vector…

Differential Geometry · Mathematics 2019-08-29 Eugene Lerman

Let H be a symplectic vector space, let V be a vector space, and consider the nilpotent Lie algebra L_H(V) = H \otimes V + S^2(V) with bracket [(h_1 \otimes v_1;a_1),(h_2 \otimes v_2;a_2)] = (0,<h_1,h_2> v_1 v_2) . In this paper, we…

K-Theory and Homology · Mathematics 2007-05-23 E. Getzler

We develop a new, intrinsic, computationally friendly approach to Lie coalgebras through graph coalgebras, which are new and likely to be of independent interest. Our graph coalgebraic approach has advantages both in finding relations…

Algebraic Topology · Mathematics 2009-01-16 Dev Sinha , Ben Walter

We construct examples of two-step and three-step nilpotent Lie groups whose automorphism groups are `small' in the sense of either not having a dense orbit for the action on the Lie group, or being nilpotent (the latter being stronger).…

Dynamical Systems · Mathematics 2007-05-23 S. G. Dani

The structure of a solvable Lie groups admitting an Einstein left-invariant metric is, in a sense, completely determined by the nilradical of its Lie algebra. We give an easy-to-check necessary and sufficient condition for a nilpotent…

Differential Geometry · Mathematics 2007-08-01 Y. Nikolayevsky

A Lie algebra $L$ is said to be of breadth $k$ if the maximal dimension of the images of left multiplication by elements of the algebra is $k$. In this paper we give characterization of finite dimensional nilpotent Lie algebras of breadth…

Rings and Algebras · Mathematics 2014-10-13 Borworn Khuhirun , Kailash C. Misra , Ernie Stitzinger

We associate a graph ${\mathcal N}_{S}$ with a semigroup $S$ (called the upper non-nilpotent graph of $S$). The vertices of this graph are the elements of $S$ and two vertices are adjacent if they generate a semigroup that is not nilpotent…

Group Theory · Mathematics 2014-03-03 E. Jespers , M. H. Shahzamanian

We study generalized complex structures and $T$-duality (in the sense of Bouwknegt, Evslin, Hannabuss and Mathai) on Lie algebras and construct the corresponding Cavalcanti and Gualtieri map. Such a construction is called "Infinitesimal…

Differential Geometry · Mathematics 2018-07-04 Viviana del Barco , Lino Grama , Leonardo Soriani