Motivated by applications to Mackey functors, Serge Bouc characterized pullback and finite coproduct preserving functors between categories of permutation representations of finite groups. Initially surprising to a category theorist, this result does have a categorical explanation which we provide.
Keywords: topos, permutation representations, limits and colimits, adjunction, Mackey functors
2000 MSC: 58A03, 18A30
Theory and Applications of Categories, Vol. 16, 2006, No. 28, pp 771-784.
A corrigendum is published as Theory and Applications of Categories, Vol. 18, 2007, No. 5, pp 150-156.http://www.tac.mta.ca/tac/volumes/16/28/16-28.dvi