34,463 research outputs found
Operads from posets and Koszul duality
We introduce a functor from the category of posets to the category
of nonsymmetric binary and quadratic operads, establishing a new connection
between these two categories. Each operad obtained by the construction provides a generalization of the associative operad because all of its
generating operations are associative. This construction has a very singular
property: the operads obtained from are almost never basic. Besides,
the properties of the obtained operads, such as Koszulity, basicity,
associative elements, realization, and dimensions, depend on combinatorial
properties of the starting posets. Among others, we show that the property of
being a forest for the Hasse diagram of the starting poset implies that the
obtained operad is Koszul. Moreover, we show that the construction
restricted to a certain family of posets with Hasse diagrams satisfying some
combinatorial properties is closed under Koszul duality.Comment: 40 page
Identities of finitely generated graded algebras with involution
We consider associative algebras with involution graded by a finite abelian
group G over a field of characteristic zero. Suppose that the involution is
compatible with the grading. We represent conditions permitting
PI-representability of such algebras. Particularly, it is proved that a
finitely generated (Z/qZ)-graded associative PI-algebra with involution
satisfies exactly the same graded identities with involution as some finite
dimensional (Z/qZ)-graded algebra with involution for any prime q or q = 4.
This is an analogue of the theorem of A.Kemer for ordinary identities, and an
extension of the result of the author for identities with involution. The
similar results were proved also recentely for graded identities
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