center of an additive category

The **center of an additive category** $A$ is the endomorphism ring of the identity functor $Id_A$ (cf. with center).

In general, the center is not functorial, but it is functorial in some important special circumstances, like some reconstruction theorems in the commutative setup. (It is also functorial on equivalences.)

An early occurence of the definition of the center of an additive category is in section 5.d of

- Pierre Gabriel, Des catégories abéliennes, Bulletin de la Société Mathématique de France
**90**(1962), 323-448 (numdam)

Revised on April 8, 2013 21:51:10
by Urs Schreiber
(82.113.99.18)