Structured colimits via internal algebras

Mark Weber – 28 March 2012

The theory of internal algebras, originally due to Batanin, is recalled as a part of 2-dimensional monad theory. It is used to provide the combinatorial objects which enable one to organise better various colimit calculations arising in operad theory, such as the computation of free operads of various kinds or the calculation of colimits in the category of algebras of a given operad.