Algebra, Combinatorics and Number Theory

Estimating length of non-associative algebras

The length of a finite system of generators for a finite-dimensional algebra over a field is the least positive integer $k$ such that the products of length not exceeding $k$ span this algebra as a vector space.The maximum length for the systems of generators of an algebra is called the length of this algebra. Length function is an important invariant widely used to study finite dimensional algebras since 1959. The length evaluation is a difficult problem.  For example, the length of the full matrix algebra is still  unknown.

Groups with a solvable subgroup of prime-power index

I will present some results that were obtained in collaboration with Csaba Schneider (Universidade Federal de Minas Gerais) concerning groups that have a solvable subgroup of prime-power index. Under weak conditions such groups are solvable and, when they are not, the index of their solvable radical is asymptotically small. 
 

Keywords: Solvability and Fermat primes

The twisted partial group algebra and (co)homology of partial crossed products

Given a group $G$ and a partial factor set $\sigma $ of $G,$ we introduce the twisted partial group algebra $\kappa_{par}^{\sigma}G,$ which governs the partial projective $\sigma $-representations of $G$ into algebras over a field $\kappa .$ Using the relation between partial projective representations and twisted partial actions we endow $\kappa_{par}^{\sigma}G$   with the structure of a crossed product by a twisted partial action of $G$ on a commutative subalgebra of $\kappa_{par}^{\sigma}G.$   Then, we use twisted partial group algebras to obtain a first quadrant Grothendieck spectral se

Admissible representation of vertex algebras

The simple positive energy representations for an affine vertex algebras associated to higher rank Lie algebras of type $A$ and admissible levels whose top spaces are induced modules of cuspidal representation of type $A$ are extensively studied. Note that all simple weight modules with finite-dimensional weight spaces are classified. However, the general classification of simple admissible weight modules of type $A$ is not know. In this talk, we explain the recent developments in the general open problem.

Generalized polynomial identities and $2 \times 2$ upper triangular matrices

Let $A$ be an associative algebra over a field $F$ of characteristic zero, $F\langle X \rangle$ be the free algebra generated by the countable set $X=\{x_1,x_2,\ldots \}$ and $W$ be a unitary algebra over $F$. Then $A$ is called $W$-algebra if it has a structure of $W$-bimodule with some additional conditions. 

On the Kantor product and conservative algebras

In 1972, Kantor introduced the class of conservative algebras, which contains many other important classes of algebras, for example, associative, Lie, Jordan, and Leibniz algebras. Initially, we will discuss some known results about conservative algebras, and especially the algebra $U(n)$ (space of bilinear multiplications on the n-dimensional space $V_n$). Then, we will present results obtained on the study of the Kantor product (product defined in $U(n)$). In particular, we will study the Kantor product of some finite-dimensional algebras.