Timeline for What does the classifying space of a category classify?

8 events

when toggle format	what		by	license	comment
S Jan 17, 2015 at 12:28	history	suggested	Pierre Cagne	CC BY-SA 3.0	LaTeXified.
Jan 17, 2015 at 11:53	review	Suggested edits
S Jan 17, 2015 at 12:28
May 7, 2010 at 22:39	comment	added	Matthew Morrow		While recently reading V. Srinvas book "Algebraic K-theory", I learned the following (lemma 6.1), which is contained in what Peter says: The category of covering spaces of $BC$ is naturally equivalent to the category of functors $F:C\to\mbox{Sets}$ for which $F(f)$ is an isomorphism for every morphism $f$ in $C$. (Via the usual fibre construction: Fix a covering space. Then each object $X$ in $C$ gives a point of $BC$, and taking the fibre in the covering space gives a set; this gives the functor $C\to \mbox{Sets}$.)
May 7, 2010 at 18:27	history	edited	Allen Knutson	CC BY-SA 2.5	Moerdijk
May 7, 2010 at 17:17	history	edited	Peter Arndt	CC BY-SA 2.5	orthography
May 7, 2010 at 16:01	vote	accept	Don Stanley
May 7, 2010 at 16:01	vote	accept	Don Stanley
May 7, 2010 at 16:01
May 7, 2010 at 14:43	history	answered	Peter Arndt	CC BY-SA 2.5