Michael Zhao Memorial Student Colloquium
Each week, the Michael Zhao Memorial Student Colloquium holds 45minute talks by Columbia mathematics
faculty about their own research. The talks are intended for current PhD students in mathematics at Columbia.
If you are an undergraduate student or external graduate student and would like to come, please email
ams2637@columbia.edu or
rh3101@columbia.edu.
When: Tuesday 6:00  7:00 PM ET
Where: Mathematics Building, Room 520
Organizers: Alex Scheffelin, Rafah Hajjar Muñoz
When: Tuesday 6:00  7:00 PM ET
Where: Mathematics Building, Room 520
Organizers: Alex Scheffelin, Rafah Hajjar Muñoz
Exceptions: On September 26th, the Colloquium will meet in room 528.
Date  Speaker  Title and Abstract 

September 19  James Hotchkiss 
I will give an introduction to Brauer groups as they appear in a few different contexts:
fields and algebraic varieties, topological spaces, and complex manifolds.
In each context, one meets the same two problems, known as Grothendieck's question and the
periodindex problem. I will explain what is known and what is open, and describe some recent
progress in all three cases.

September 26  Yoonjoo Kim 
A compact hyperKähler manifold is an extremely special compact Kähler manifold,
whose local charts are given by the quaternionic space H^n. It naturally appears
in certain classification theorems in both differential and algebraic geometry.
Its rigid and special nature is well reflected in its (singular) cohomology.
I will introduce the definition of a compact hyperKähler manifold and its basic
cohomology theory. We will focus on its Hodge theoretic behavior.

October 3  TBD  TBD 
October 10  TBD  TBD 
October 17  TBD  TBD 
October 24  TBD  TBD 
October 31  TBD  TBD 
November 7     
November 14  TBD  TBD 
November 21  TBD  TBD 
November 28  TBD  TBD 
December 5  TBD  TBD 