Southern Wisconsin Logic Colloquium

SWLC Schedule

Refreshments will be served in the 9th floor lounge a half hour before talks. Please check the schedule below. All talks will be in 901 Van Vleck Hall unless stated otherwise.

Date Time Speaker Title Cookies,
dinner, etc.
Tuesday, September 10 4:00 p.m. Arnie Miller, UW TBA cookies/ beverages at 3:30

Math 873 - Fall 2013 - Reverse Mathematics of Combinatorial Principles

Instructor: Steffen Lempp
Course Description: Reverse mathematics tries to pinpoint the exact axioms needed to prove a theorem in "ordinary" mathematics, ideally by showing that the proof can be "reversed" and a certain set of axioms can be proved from the theorem (over a weaker base theory, usually RCA0, the theory corresponding to "computable mathematics").

Most theorems in analysis and algebra reverse to one of just five "big" axiom systems. Combinatorics, however, yields a large number of new axiom systems, and the relationship between these has been the subject of intense investigation for several decades.

I plan to start with the seminal 1972 paper by Jockusch on computable combinatorics and continue with highlights like Seetapun's 1995 separation of Ramsey's Theorem for Pairs from the axiom system ACA0, the Cholak/Jockusch/Slaman 2001 paper expanding Seetapun's result in a number of ways, the 2007 and 2009 papers by Hirschfeldt/Shore and Hirschfeldt/Slaman/Shore on order-theoretic principles and theorems from model theory, and the recent papers by Liu (showing that Ramsey's Theorem for Pairs does not imply Weak König's Lemma), by Chong/Slaman/Yang (that the stable version of Ramsey's Theorem does not imply the full version) and by Wang (that Thin Set Theorem implies almost no other combinatorial principle).

Math 975 - Reading Seminar in Logic

Our reading seminar is meeting on Wednesdays at 3:30 in room B129 Van Vleck Hall.

Prepared by Steffen Lempp (@math.wisc.edu">lemppmath.wisc.edu)