Abstract:
In the study of different mathematical structures well known and
long used in mathematics algebraic method is the selection of
classes of objects by means of identities. Class of all linear
algebras over some field in which a fixed set of identities takes
place is called the variety of linear algebras over a given field by
A.I. Malcev. We have such concept as the growth of the variety.
There is polynomial or exponential growth in mathematical analysis.
In this work we will speak about properties of some varieties in
different classes of linear algebras over zero characteristic field
with almost polynomial growth. That means that the growth of the
variety is not polynomial, but the growth of any its own subvariety
is polynomial. The article has a synoptic and abstract character.
One unit of the article is devoted to the description of basic
properties all associative, Lie's and Leibniz's varieties over zero
characteristic field with almost polynomial growth. In the case of
associative algebras there are only two such varieties. In the class
of Lie algebras there are exactly four solvable varieties with
almost polynomial growth and is found one unsolvable variety wiht
almost polynomial growth and the question about its uniqueness is
opened in our days. In the case of Leibniz algebras there are nine
varieties with almost polynomial growth. Five of them are named
before Lie varieties, which are Leibniz varieties too. The last four
ones are varieties which have the same properties as solvable Lie
varieties of almost polynomial growth.
Next units we'll devote to famous and new characteristics of two
Lie's varieties with almost polynomial growth. In the first of them
we speak about found by us colength of the variety generated by
three-dimensional simple Lie algebra $sl_2$, which is formed by a
set of all $2\times2$ matrices with zero trace over a basic field
with operation of commutation.
Then it will be described a basis of multilinear part of the variety
which consists of Lie algebras with nilpotent commutant degree not
higher than two. Also we'll give formulas for its colength and
codimension.
The last unit is devoted to description the basis of multilinear
part of Leibniz variety with almost polynomial growth defined by the
identity $x_1(x_2x_3)(x_4x_5)\equiv0$.
Keywords:variety, almost polynomial growth, colength, codimension, basis of multilinear part.