where μA (resp. μB) is the multiplication of A (resp. B). We deduce that the ”natural” tensor product μA⊗B = μA ⊗ μB provides A⊗ B with a Lie-admissible algebra structure. In [2] we have defined special classes of Lie-admissible algebras with relations of definition determined by an action of the subgroupsGi of the 3-degree symmetric group Σ3. We obtain quadratic operads, denoted by Gi−Ass and ...

We investigate algebras with one operation. We study when these algebras form a monoidal category and analyze Koszulness and cyclicity of the corresponding operads. We also introduce a new kind of symmetry for operads, the dihedrality , responsible for the existence of dihedral cohomology. The main trick, which we call the polarization, will be to represent an algebra with one operation without...

There have been a number of mathematical results recently identifying algebras over certain operads [4, 25, 17, 28, 16, 10, 14, 11]. See [1, 26] for expository surveys of the basics of operad theory. Before citing any of these results, let us mention some trivial classical examples. Let A denote one of the three words: “commutative”, “associative” and “Lie”. In each of these cases, consider the...

The most familiar example of higher, or vertically iterated enrichment is that in the definition of strict n-category. We begin with strict n-categories based on a general symmetric monoidal category V. Motivation is offered through a comparison of the classical and extended versions of topological quantum field theory. A sequence of categorical types that filter the category of monoidal catego...

This preprint is an extract from a research monograph in preparation on the homotopy of operads and Grothendieck-Teichmüller groups. The ultimate objective of this book is to prove that the Grothendieck-Teichmüller group is the group of homotopy automorphisms of a rational completion of the little 2-discs operad. The present excerpts include a comprehensive account of the fundamental concepts o...

The subject of this thesis is to study the Little Disk operad and the Cacti operad and show that they are equivalent as operads as presented by Kaufmann in the article [Kau05]. In doing so, we go through a preliminary study of operads, what it means for them to be equivalent and the problems involved. We introduce and use the Little Disk in the process. We furthermore introduce and show results...

We show that the family of standard simplices and the family of Stasheff polytopes are dual to each other in the following sense. The chain modules of the standard simplices, resp. the Stasheff polytopes, assemble to give an operad. We show that these operads are dual of each other in the operadic sense. The main result of this paper is to show that they are both Koszul operads. This theorem ap...