Search results for " *-codimension"
showing 7 items of 7 documents
Polynomial growth and identities of superalgebras and star-algebras
2009
Abstract We study associative algebras with 1 endowed with an automorphism or antiautomorphism φ of order 2, i.e., superalgebras and algebras with involution. For any fixed k ≥ 1 , we construct associative φ -algebras whose φ -codimension sequence is given asymptotically by a polynomial of degree k whose leading coefficient is the largest or smallest possible.
Algebras with involution with linear codimension growth
2006
AbstractWe study the ∗-varieties of associative algebras with involution over a field of characteristic zero which are generated by a finite-dimensional algebra. In this setting we give a list of algebras classifying all such ∗-varieties whose sequence of ∗-codimensions is linearly bounded. Moreover, we exhibit a finite list of algebras to be excluded from the ∗-varieties with such property. As a consequence, we find all possible linearly bounded ∗-codimension sequences.
Minimal star-varieties of polynomial growth and bounded colength
2018
Abstract Let V be a variety of associative algebras with involution ⁎ over a field F of characteristic zero. Giambruno and Mishchenko proved in [6] that the ⁎-codimension sequence of V is polynomially bounded if and only if V does not contain the commutative algebra D = F ⊕ F , endowed with the exchange involution, and M , a suitable 4-dimensional subalgebra of the algebra of 4 × 4 upper triangular matrices , endowed with the reflection involution. As a consequence the algebras D and M generate the only varieties of almost polynomial growth. In [20] the authors completely classify all subvarieties and all minimal subvarieties of the varieties var ⁎ ( D ) and var ⁎ ( M ) . In this paper we e…
Polynomial growth and star-varieties
2016
Abstract Let V be a variety of associative algebras with involution over a field F of characteristic zero and let c n ⁎ ( V ) , n = 1 , 2 , … , be its ⁎-codimension sequence. Such a sequence is polynomially bounded if and only if V does not contain the commutative algebra F ⊕ F , endowed with the exchange involution, and M, a suitable 4-dimensional subalgebra of the algebra of 4 × 4 upper triangular matrices. Such algebras generate the only varieties of ⁎-algebras of almost polynomial growth, i.e., varieties of exponential growth such that any proper subvariety is polynomially bounded. In this paper we completely classify all subvarieties of the ⁎-varieties of almost polynomial growth by gi…
On Codimensions of Algebras with Involution
2020
Let A be an associative algebra with involution ∗ over a field F of characteristic zero. One associates to A, in a natural way, a numerical sequence \(c^{\ast }_n(A),\)n = 1, 2, …, called the sequence of ∗-codimensions of A which is the main tool for the quantitative investigation of the polynomial identities satisfied by A. In this paper we focus our attention on \(c^{\ast }_n(A),\)n = 1, 2, …, by presenting some recent results about it.
Polynomial codimension growth of graded algebras
2009
We study associative $G$-graded algebras with 1 of polynomial $G$-codimension growth, where $G$ is a finite group. For any fixed $k\geq 1,$ we construct associative $G$-graded algebras of upper triangular matrices whose $G$-codimension sequence is given asymptotically by a polynomial of degree $k$ whose leading coefficient is the largest or smallest possible.
Supervarieties and *-varieties of algebras of polynomial growth
2008
We study the sequence of supercodimensions and *-codimensions of unitary algebras.