Calibrating the strength of Ramsey's theorem is one of the central
topic in the study of reverse mathematics. In this talk, I will talk
about the recent studies on the strength of Ramsey's theorem, mainly
from the view points of the proof-theoretic strength and the
size/length of proofs.
(Organizer's note: Yokoyama will be discussing the work featured last year in this article: https://www.quantamagazine.org/20160524-mathematicians-bridge-finite-inf...)