By Axel Osmond
For a model of a geometric theory in a Grothendieck topos, we can construct the over-topos of this model classifying homomorphisms above it. In this talk, we provide a site theoretic description of this construction. In the case of a set-valued model, a site will be provided by the category of global elements together with a certain antecedents topology, and we can describe a canonical geometric theory classified by this over-topos. In the general case, one must consider a more complicated category of generalized elements ; an antecedent topology then can be recovered through a notion of lifted topology, whose construction can be understood in the framework of stacks and comorphisms of sites.
This is joint work with Olivia Caramello.
By Dustin Clausen
By Riccardo Zanfa
By Jean-Claude Belfiore
By Daniel Bennequin
By Samson Abramsky
By Jens Hemelaer
By Francesco Genovese
By Clément Delcamp
By Christoph Koutschan
By Christoph Koutschan
By Christiane Koch
By Marie Kerjean
By Misha Gromov
