scholarly journals Linear Bundle of Lie Algebras Applied to the Classification of Real Lie Algebras

Symmetry ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1455
Author(s):  
Alina Dobrogowska ◽  
Karolina Wojciechowicz
Keyword(s):  
Lie Algebras ◽  
Hamiltonian Structure ◽  
Three Dimensional ◽  
Poisson Structures ◽  
Triangular Matrices ◽  
Dual Spaces ◽  
Upper Triangular Matrices ◽  
Low Dimensional ◽  
Algebra Level

We present a new look at the classification of real low-dimensional Lie algebras based on the notion of a linear bundle of Lie algebras. Belonging to a suitable family of Lie bundles entails the compatibility of the Lie–Poisson structures with the dual spaces of those algebras. This gives compatibility of bi-Hamiltonian structure on the space of upper triangular matrices and with a bundle at the algebra level. We will show that all three-dimensional Lie algebras belong to two of these families and four-dimensional Lie algebras can be divided in three of these families.

The classification of three-dimensional Lie algeb­ras on complex field

2020 ◽  
pp. 143-155
Author(s):  
E. R. Shamardina
Keyword(s):  
Lie Algebra ◽  
Lie Algebras ◽  
Three Dimensional ◽  
Structural Equations ◽  
Complex Numbers ◽  
Complex Field ◽  
Low Dimensional

In this paper, we study the classification of three-dimensional Lie al­gebras over a field of complex numbers up to isomorphism. The proposed classification is based on the consideration of objects invariant with re­spect to isomorphism, namely such quantities as the derivative of a subal­gebra and the center of a Lie algebra. The above classification is distin­guished from others by a more detailed and simple presentation. Any two abelian Lie algebras of the same dimension over the same field are isomorphic, so we understand them completely, and from now on we shall only consider non-abelian Lie algebras. Six classes of three-dimensional Lie algebras not isomorphic to each other over a field of complex numbers are presented. In each of the classes, its properties are described, as well as structural equations defining each of the Lie alge­bras. One of the reasons for considering these low dimensional Lie alge­bras that they often occur as subalgebras of large Lie algebras

scholarly journals Minimal linear representations of the low-dimensional nilpotent Lie algebras

2008 ◽  
Vol 102 (1) ◽  
pp. 17 ◽  
Author(s):  
J. C. Benjumea ◽  
J. Núnez ◽  
A. F. Tenorio
Keyword(s):  
Lie Algebras ◽  
Nilpotent Lie Algebra ◽  
Matrix Representations ◽  
Triangular Matrices ◽  
Nilpotent Lie Algebras ◽  
Linear Representations ◽  
Minimal Dimension ◽  
The Matrix ◽  
Low Dimensional

The main goal of this paper is to compute a minimal matrix representation for each non-isomorphic nilpotent Lie algebra of dimension less than $6$. Indeed, for each of these algebras, we search the natural number $n\in\mathsf{N}\setminus\{1\}$ such that the linear algebra $\mathfrak{g}_n$, formed by all the $n \times n$ complex strictly upper-triangular matrices, contains a representation of this algebra. Besides, we show an algorithmic procedure which computes such a minimal representation by using the Lie algebras $\mathfrak{g}_n$. In this way, a classification of such algebras according to the dimension of their minimal matrix representations is obtained. In this way, we improve some results by Burde related to the value of the minimal dimension of the matrix representations for nilpotent Lie algebras.

scholarly journals Classification of real low-dimensional Jacobi (generalized)–Lie bialgebras

2016 ◽  
Vol 14 (01) ◽  
pp. 1750007 ◽  
Author(s):  
A. Rezaei-Aghdam ◽  
M. Sephid
Keyword(s):  
Lie Groups ◽  
Lie Algebras ◽  
Three Dimensional ◽  
Lie Bialgebras ◽  
Structure Constants ◽  
Definition Of ◽  
Low Dimensional

We describe the definition of Jacobi (generalized)–Lie bialgebras [Formula: see text] in terms of structure constants of the Lie algebras [Formula: see text] and [Formula: see text] and components of their 1-cocycles [Formula: see text] and [Formula: see text] in the basis of the Lie algebras. Then, using adjoint representations and automorphism Lie groups of Lie algebras, we give a method for classification of real low-dimensional Jacobi–Lie bialgebras. In this way, we obtain and classify real two- and three-dimensional Jacobi–Lie bialgebras.

Low-dimensional lattices. VI. Voronoi reduction of three-dimensional lattices

1992 ◽  
Vol 436 (1896) ◽  
pp. 55-68 ◽  
Keyword(s):  
Simple Formula ◽  
Three Dimensional ◽  
Voronoi Cell ◽  
Dimensional Lattice ◽  
Usual Treatment ◽  
Low Dimensional

The aim of this paper is to describe how the Voronoi cell of a lattice changes as that lattice is continuously varied. The usual treatment is simplified by the introduction of new parameters called the vonorms and conorms of the lattice. The present paper deals with dimensions n ≼ 3; a sequel will treat four-dimensional lattices. An elegant algorithm is given for the Voronoi reduction of a three-dimensional lattice, leading to a new proof of Voronoi’s theorem that every lattice of dimension n ≼ 3 is of the first kind, and of Fedorov’s classification of the three-dimensional lattices into five types. There is a very simple formula for the determinant of a three-dimensional lattice in terms of its conorms.

VERSAL DEFORMATIONS OF THREE-DIMENSIONAL LIE ALGEBRAS AS L∞ ALGEBRAS

2005 ◽  
Vol 07 (02) ◽  
pp. 145-165 ◽  
Author(s):  
ALICE FIALOWSKI ◽  
MICHAEL PENKAVA
Keyword(s):  
Vector Space ◽  
Lie Algebras ◽  
Moduli Space ◽  
Deformation Theory ◽  
Three Dimensional ◽  
3 Dimensional ◽  
Exterior Degree ◽  
Versal Deformations

We consider versal deformations of 0|3-dimensional L∞ algebras, also called strongly homotopy Lie algebras, which correspond precisely to ordinary (non-graded) three-dimensional Lie algebras. The classification of such algebras is well-known, although we shall give a derivation of this classification using an approach of treating them as L∞ algebras. Because the symmetric algebra of a three-dimensional odd vector space contains terms only of exterior degree less than or equal to three, the construction of versal deformations can be carried out completely. We give a characterization of the moduli space of Lie algebras using deformation theory as a guide to understanding the picture.

COMPUTING THE LAW OF A FAMILY OF SOLVABLE LIE ALGEBRAS

2009 ◽  
Vol 19 (03) ◽  
pp. 337-345 ◽  
Author(s):  
JUAN C. BENJUMEA ◽  
JUAN NÚÑEZ ◽  
ÁNGEL F. TENORIO
Keyword(s):  
Lie Algebra ◽  
Lie Algebras ◽  
Lie Group ◽  
Triangular Matrices ◽  
Upper Triangular Matrices ◽  
Computational Data ◽  
Solvable Lie Algebras ◽  
Final Output ◽  
The Matrix ◽  
The Law

This paper shows an algorithm which computes the law of the Lie algebra associated with the complex Lie group of n × n upper-triangular matrices with exponential elements in their main diagonal. For its implementation two procedures are used, respectively, to define a basis of the Lie algebra and the nonzero brackets in its law with respect to that basis. These brackets constitute the final output of the algorithm, whose unique input is the matrix order n. Besides, its complexity is proved to be polynomial and some complementary computational data relative to its implementation are also shown.

Material rotating frame, rate-independent plasticity with regularization of Schmid law and study of channel-die compression

2017 ◽  
Vol 24 (1) ◽  
pp. 18-39
Author(s):  
Karim Fathallah ◽  
Ahmed Chenaoui ◽  
Michel Darrieulat ◽  
Abdelwaheb Dogui
Keyword(s):  
Three Dimensional ◽  
Phenomenological Approach ◽  
Frame Rate ◽  
Common Element ◽  
Rotating Frame ◽  
Phenomenological Method ◽  
Large Plastic Deformation ◽  
Triangular Matrices ◽  
Upper Triangular Matrices ◽  
Velocity Tensor

Metals often exhibit several crystallographic components that rotate when subjected to large plastic deformation. Studying their evolution constitutes a prospect to apply the finite plastic strain theory. In this respect, this research paper formulates a three-dimensional extension of Dogui’s plane kinematics to choose a material rotating frame in which deformation and velocity tensor gradients are represented by upper triangular matrices. This technique facilitates numerical calculation and renders it faster. This can prove to be useful if used for crystalline calculation. We study the kinematics of a channel-die loading to implement the material rotating frame model. The rate-independent formulation, which uses the multi-surface theory to represent the plastic flow of crystals, often leads to slip indeterminacy. Hence, we have developed a phenomenological method to solve such a difficulty using the regularization of Schmid’s yield law. As a significant application of this proposed phenomenological approach, aluminium crystal flow in channel-die compression is numerically simulated for three cases of loadings: (i) classical rolling components Cube, Goss, Brass, Copper and Dillamore orientations; (ii) {110} compression; and (iii) Strange orientation, which has no common element of symmetry with the channel-die. A good correlation between the simulation results and the available experimental ones is observed.

scholarly journals Classification of three-dimensional complex $\omega$-Lie algebras

2014 ◽  
Vol 71 (2) ◽  
pp. 97-108 ◽  
Author(s):  
Yin Chen ◽  
Chang Liu ◽  
Runxuan Zhang
Keyword(s):  
Lie Algebras ◽  
Three Dimensional
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