A Remark on Mackey-functors
نویسنده
چکیده
In the following note we characterize the category of Mackey-functors from a category ~, satisfying a few assumptions, to a category ~ as the category of functors from Sp(~), the category of "spans" in ~, to ~ which preserve finite products. This caracterization permits to apply all results on categories of functors preserving a given class of limits to the case of Mackey-functors. We recall (cf. [3], w the definition of a Mackey-functor: (ii) !~f (I) i_ss ~ pullback diagram i_~n ~, then the diagram (2) commutes: A f)C MA-N~f >MC (iii) M~ : ~o____~ preserves finite products.
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