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.
http://www.tac.mta.ca/tac/volumes/16/28/16-28.dvi
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ftp://ftp.tac.mta.ca/pub/tac/html/volumes/16/28/16-28.dvi
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