November 27
Corey Switzer, CUNY
Why PA?

Peano’s original investigations into the foundations of arithmetic led to the observation that the axioms of PA are categorical for the Natural Numbers when treated in 2nd order logic. In this talk we will give a proof of Wilkie’s theorem which states that PA is in a sense the least such theory with this property. Arguably this justifies its significance in foundational studies. The proof uses the method of (L, n)-models, which I have previously talked about and I’ll discuss it’s use here as well.