You are cordially invited to the Graduate Mathematics Seminar Series organized by the Department of Mathematics.
Speaker: Mehmet Kırtışoğlu (Bilkent University)
“Thomason Cohomology and Quillen’s Theorem A”
Abstract: We Given a functor φ : C->D between small categories, Quillen showed that there is a homotopy equivalence κ : hocolim_D N(φ/-)-> NC, where N(φ/-) is the functor that sends each object d of D to the nerve of the comma category φ/d. We show that the homotopy equivalence κ induces an isomorphism on the Gabriel-Zisman cohomology of the associated simplicial sets. As a consequence, we obtain a version of Quillen’s Theorem A for the Thomason cohomology of categories. We also construct a spectral sequence converging to the Thomason cohomology of the Grothendieck construction of a functor F : D -> Cat with arbitrary coefficients.
This a joint work with my advisor Prof. Dr. ERGÜN YALÇIN.
Advisor: Prof. Dr. ERGÜN YALÇIN.
Date: 07.05.2026
Time: 13:30
Place: SA- 141