Affordable Access

Publisher Website

The Eckmann–Hilton argument and higher operads

Advances in Mathematics
Publication Date
DOI: 10.1016/j.aim.2007.06.014
  • Operad
  • N-Category
  • Cartesian Monad
  • Mathematics


Abstract The classical Eckmann–Hilton argument shows that two monoid structures on a set, such that one is a homomorphism for the other, coincide and, moreover, the resulting monoid is commutative. This argument immediately gives a proof of the commutativity of the higher homotopy groups. A reformulation of this argument in the language of higher categories is: suppose we have a one object, one arrow 2-category, then its Hom-set is a commutative monoid. A similar argument due to A. Joyal and R. Street shows that a one object, one arrow tricategory is ‘the same’ as a braided monoidal category. In this paper we begin to investigate how one can extend this argument to arbitrary dimension. We provide a simple categorical scheme which allows us to formalise the Eckmann–Hilton type argument in terms of the calculation of left Kan extensions in an appropriate 2-category. Then we apply this scheme to the case of n-operads in the author's sense and classical symmetric operads. We demonstrate that there exists a functor of symmetrisation Sym n from a certain subcategory of n-operads to the category of symmetric operads such that the category of one object, one arrow, … , one ( n − 1 ) -arrow algebras of A is isomorphic to the category of algebras of Sym n ( A ) . Under some mild conditions, we present an explicit formula for Sym n ( A ) which involves taking the colimit over a remarkable categorical symmetric operad. We will consider some applications of the methods developed to the theory of n-fold loop spaces in the second paper of this series.

There are no comments yet on this publication. Be the first to share your thoughts.