Operads in iterated monoidal categories.
Operads of decorated trees and their duals
This is an extended version of a talk presented by the second author on the Third Mile High Conference on Nonassociative Mathematics (August 2013, Denver, CO). The purpose of this paper is twofold. First, we would like to review the technique developed in a series of papers for various classes of di-algebras and show how the same ideas work for tri-algebras. Second, we present a general approach to the definition of pre- and post-algebras which turns out to be equivalent to the construction of dendriform...
Operády v současné matematice
Properads and homological differential operators related to surfaces
We give a biased definition of a properad and an explicit example of a closed Frobenius properad. We recall the construction of the cobar complex and algebra over it. We give an equivalent description of the algebra in terms of Barannikov’s theory which is parallel to Barannikov’s theory of modular operads. We show that the algebra structure can be encoded as homological differential operator. Example of open Frobenius properad is mentioned along its specific properties.
Quotients of unital -categories.
Reedy categories which encode the notion of category actions
We study a certain type of action of categories on categories and on operads. Using the structure of the categories Δ and Ω governing category and operad structures, respectively, we define categories which instead encode the structure of a category acting on a category, or a category acting on an operad. We prove that the former has the structure of an elegant Reedy category, whereas the latter has the structure of a generalized Reedy category. In particular, this approach gives a new way to regard...
Roots of unity as a Lie algebra.
Shellability of a poset of polygonal subdivisions.
Shuffle bialgebras
The goal of our work is to study the spaces of primitive elements of some combinatorial Hopf algebras, whose underlying vector spaces admit linear basis labelled by subsets of the set of maps between finite sets. In order to deal with these objects we introduce the notion of shuffle algebras, which are coloured algebras where composition is not always defined. We define bialgebras in this framework and compute the subpaces of primitive elements associated to them. These spaces of primitive elements...
Structure theory for the group algebra of the symmetric group, with applications to polynomial identities for the octonions
This is a survey paper on applications of the representation theory of the symmetric group to the theory of polynomial identities for associative and nonassociative algebras. In §1, we present a detailed review (with complete proofs) of the classical structure theory of the group algebra of the symmetric group over a field of characteristic 0 (or ). The goal is to obtain a constructive version of the isomorphism where is a partition of and counts the standard tableaux of shape ....
Superalgebras and operads. I.
Superization and -specialization in combinatorial Hopf algebras.
Sur une opérade ternaire liée aux treillis de Tamari
On introduit une opérade anticyclique définie par une présentation ternaire quadratique. On montre qu’elle admet une base indexée par les arbres binaires planaires. On relie cette construction à la famille des treillis de Tamari en construisant un isomorphisme entre et le groupe de Grothendieck de la catégorie qui envoie la base de sur les classes des modules projectifs et qui transforme la structure anticyclique de en la transformation de Coxeter de la catégorie dérivée de . La dualité...
The associative operad and the weak order on the symmetric groups.
Théorie des opérades de Koszul et homologie des algèbres de Poisson
Towards an -category of cobordisms.
Une opérade anticyclique sur les arbustes
We define new combinatorial objects, called shrubs, such that forests of rooted trees are shrubs. We then introduce a structure of operad on shrubs. We show that this operad is contained in the Zinbiel operad, by using the inclusion of Zinbiel in the operad of moulds. We also prove that this inclusion is compatible with the richer structure of anticyclic operad that exists on Zinbiel and on moulds.