Revisiting Seetapun’s theorem with his disjunction
Date/Time:29 Aug 2019 17:00Venue: S17 #06-11Speaker: Chong Chi Tat, National University of SingaporeRevisiting Seetapun’s theorem with his disjunctionRamsey’s theorem RT^n_2 states that if the n-rtuples of the set of natural numbers are coloured in either red or blue, then there is an infinite subset all of whose n-tuples have the same color. The proof-theoretic strength of RT^n_2 has been a prominent line of study in reverse mathematics. The first major breakthrough was obtained by David Seetapun (Seetapun and Slaman (1995)) who showed that RT^2_2 is strictly weaker than RT^3_2. This talk will describe a proof of this theorem using the technique called “Seetapun disjunction” introduced in Chong, Slaman and Yang (2014).Add to calendar:
