Feb 10th, Grisha Taroian, Homological algebra in topoi III

This is the continuation of the previous 2 talks. We will (finally) define the Chech cohomology for objects in (Grothendieck) topoi. Also, we will start discussing the presentation of $H^1(\mathcal{E};G)$ as a group of $G$-torsors on $\mathcal{E}.$ The talk is still based on Chapter 8 in Johnstone's "Topos Theory"