Combinatorial structures associated with Lie algebras of finite dimension (original) (raw)

Study of Lie algebras by using combinatorial structures

Linear Algebra and its Applications, 2012

In this paper, we study the structure and properties of those n-dimensional Lie algebras associated with either summed structures of complete graphs or some families of digraphs, having into consideration that all these combinatorial structures are made up of n vertices. Our main goal is to obtain criteria determining when a Lie algebra is associated with some of combinatorial structures considered in this paper, as well as to study the properties of those structures in order to use them as a tool for classifying the types of Lie algebras associated with them.

Combinatorial structures of three vertices and Lie algebras

International Journal of Computer Mathematics, 2012

This paper shows a characterization of digraphs of three vertices associated with Lie algebras, as well as determining the list of isomorphism classes for Lie algebras associated with these digraphs. Additionally, we introduce and implement two algorithmic procedures related to this study: the first is devoted to draw, if exists, the digraph associated with a given Lie algebra; whereas the

Graph operations and Lie algebras

International Journal of Computer Mathematics, 2013

>IJH=?J This paper deals with several operations on graphs and combinatorial structures linking them with their associated Lie algebras. More concretely, our main goal is to obtain some criteria to determine when there exists a Lie algebra associated with a combinatorial structure arising from those operations. Additionally, we show an algorithmic method for one of those operations.

Low-dimensional Leibniz algebras and combinatorial structures

Given a finite-dimensional Leibniz algebra with certain basis, we show how to associate such a Lie algebra with a combinatorial structure of dimension 2. In some particular cases, this structure can be reduced to a digraph or a pseudodigraph. In this paper, we study some theoretical properties about this association and we determine the type of Leibniz algebra associated with each of these structures having no more than 3 vertices.

A combinatorial construction for simply-laced Lie algebras

Advances in Applied Mathematics, 2003

This paper shows how to uniformly associate Lie algebras to the simply-laced Dynkin diagrams excluding E 8 by constructing explicit combinatorial models of minuscule representations using only graph-theoretic ideas. This involves defining raising and lowering operators in a space of ideals of certain distributive lattices associated to sequences of vertices of the Dynkin diagram.

Combinatorial structures associated with finite-dimensional Leibniz algebras

This paper is the second in a series giving the foundations for associating Leibniz algebras with combinatorial structures of dimension 2. On this occasion, we characterize Leibniz algebras of dimension greater than 3 associated with (psuedo)digraphs and, consequently, we also study the converse, proving some properties about (pseudo)digraphs associated with Leibniz algebras. Finally, we analyze the nilpotency and solvability for Leibniz algebras associated with (pseudo)digraphs.

Combinatorial structures and Lie algebras of upper triangular matrices

Applied Mathematics Letters, 2012

This work shows how to associate the Lie algebra h n , of upper triangular matrices, with a specific combinatorial structure of dimension 2, for n ∈ N. The properties of this structure are analyzed and characterized. Additionally, the results obtained here are applied to obtain faithful representations of solvable Lie algebras.

Lie algebras associated with triangular configurations

Linear Algebra and its Applications, 2005

A new class of Lie algebras of finite dimension, those which are associated with a certain combinatorial configuration made up by triangles of weighted and non-directed edges, is introduced and a characterization theorem for them is proved. Moreover, some subclasses of such Lie algebras are classified.

Combinatorial representation theory of Lie algebras. Richard Stanley’s work and the way it was continued

The Mathematical Legacy of Richard P. Stanley, 2016

Dedicated to Richard Stanley on the occasion of his seventieth birthday. Representation theory is a fundamental tool for studying group symmetry − geometric, analytic, or algebraic − by means of linear algebra, which has important applications to other areas of mathematics and mathematical physics. One very successful trend in this field in recent decades involves using combinatorial objects to model the representations, which allows one to apply combinatorial methods for studying them, e.g., for concrete computations. This trend led to the emergence of combinatorial representation theory, which has now become a thriving area. Richard Stanley played a crucial role, through his work and his students, in the development of this new area. In the early stages, he has the merit to have pointed out to combinatorialists, in [34, 36], the potential that representation theory has for applications of combinatorial methods. Throughout his distinguished career, he wrote significant articles which touch upon various combinatorial aspects related to representation theory (of Lie algebras, the symmetric group, etc.). I will describe some of Richard's contributions involving Lie algebras, as well as recent developments inspired by them (including some open problems), which attest the lasting impact of his work. Acknowledgement. Meeting Richard was a defining moment of my life and career, as well as of my evolution since then. Therefore, I always said that I consider him my mentor. I admire him both as a person and as a scientist, while his vast work in combinatorics and on its many relationships with other areas of mathematics is a continuous inspiration for me.

Directed pseudo-graphs and lie algebras over finite fields

Czechoslovak Mathematical Journal, 2014

The main goal of this paper is to show an application of Graph Theory to classifying Lie algebras over finite fields. It is rooted in the representation of each Lie algebra by a certain pseudo-graph. As partial results, it is deduced that there exist, up to isomorphism, four, six, fourteen and thirty-four 2-, 3-, 4-, and 5-dimensional algebras of the studied family, respectively, over the field Z/2Z. Over Z/3Z, eight and twenty-two 2and 3-dimensional Lie algebras, respectively, are also found. Finally, some ideas for future research are presented.