BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Biset functors defined on categories - Peter Webb (University of M
 innesota)
DTSTART:20240610T124500Z
DTEND:20240610T131500Z
UID:TALK217318@talks.cam.ac.uk
DESCRIPTION:The classical biset category (with a modification) first arose
  in a description of the morphisms between classifying spaces of finite gr
 oups\, as a consequence of the Segal Conjecture. Biset functors are linear
  functors from this category to abelian groups. They are closely related t
 o Mackey functors\, being sometimes called globally defined Mackey functor
 s. The classical theory has since been extended in several directions: one
  is that the biset category can now be taken to have as its objects all fi
 nite categories\, rather than just all finite groups\, so that biset funct
 ors are now defined on arbitrary finite categories. A key role is played b
 y the Burnside ring of the finite category\, for which the definition is n
 ew when the category is not a group. The homology and cohomology of simpli
 cial complexes can both be regarded as biset functors\, and this provides 
 a uniform setting for the construction of transfer maps. &nbsp\;Another di
 rection of development is that both the biset category and the category of
  biset functors are monoidal\, and the biset category is\, in fact\, rigid
 . I give an overview of key aspects of this theory.
LOCATION:External
END:VEVENT
END:VCALENDAR