Speaker: Professor Shun-ichi Kimura
Department of Mathematics, Hiroshima University
Time: September 4, 16:00-17:00
Location: Room 1611, Management and Research Building, Eastern Campus
Title: Counting infinite set by K-ring

Abstract: 

When C is a category, Grothendieck defined its K-ring, generated by objects of C, in the late 1960s in his study of intersection theory on algebraic varieties (partially copied from Wikipedia), which sounds like a story of modern abstract mathematics but come to think about it, the K-ring of the category of finite sets is the integer ring to be more precise, the integer ring was prehistorically defined as the K-ring of finite sets! 
Also when we look at the K-ring of topological spaces, we can recover Euler characteristic. 
In this talk, we relate K-rings from this viewpoint with the celebrated Weil conjecture, and with our ongoing research.