## Classifying topos of a topological categoryAdd to your list(s) Download to your calendar using vCal - Sina Hazratpour, University of Birmingham
- Tuesday 14 November 2017, 14:00-16:00
- 245, School of Computer Science.
If you have a question about this talk, please contact Sina. I will begin by reviewing the ideas of points of toposes and homotopy between maps of toposes ([1],[2]). I then define for a discrete group G, the geometric theory of G-torsors whose models are G-torsors in toposes (aka principal bundles), and construct a classifying topos for this theory. This was first introduced by Grothendieck and Verdier in SGA4 . One will see that the situation is a generalization of construction of classifying spaces in algebraic topology. Next, I will show the construction of [1] S. Mac Lane and I. Moerdijk, Sheaves in geometry and logic [2] Peter Johnstone, Topos theory [3] Graeme Segal, Classifying spaces and spectral sequences [4] P. Deligne, Théorie de Hodge III [5] I.Moerdijk, Classifying spaces and classifying topoi This talk is part of the Cargo series. ## This talk is included in these lists:Note that ex-directory lists are not shown. |
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