A *symmetric endofunctor* is an endofunctor together with actions of the symmetric groups on its automorphism groups.

Let $\Phi$ be a graded monoid in the category of groups, e.g. the graded monoid $\Sigma = (\Sigma_n)_{n \ge 0}$ of symmetric groups.

A **symmetric endofunctor** $F : C \to C$ is an endofunctor together with the data of, for each $n \in \mathbf{N}$, a group homomorphism

$\Phi_n \to \Aut(F^{\circ n})$

where $F^{\circ n}$ is the $n$-fold composite of $F$.

Created on February 7, 2014 at 00:55:15. See the history of this page for a list of all contributions to it.