Dartmouth Logic Seminar

## Fall 2012

This Fall, the seminar meets every other Wednesday in Kemeny 120 at 3pm.

DateSpeakerTitle
Sep 18
Organizational Meeting
Kemeny 120 at 2pm
Sep 26
François G. Dorais
Dartmouth College
Interpreting set theory in second-order arithmetic

We will discuss the problem of interpreting fragments of set theory into subsystems of second-order arithmetic. We will see how and why $\mathsf{ATR}_0$ is the weakest subsystem of second-order arithmetic that has a robust interpretation of set theory. We will discuss what can be done in weaker subsystems such as $\mathsf{ACA}_0$ and $\mathsf{ACA}_0^+$. Finally, we will discuss potential applications to reverse mathematics.

We will begin with a review of second-order arithmetic, so familiarity with $\mathsf{ACA}_0$, $\mathsf{ACA}_0^+$, $\mathsf{ATR}_0$ and other subsystems of second-order arithmetic is not necessary.

Oct 10
François G. Dorais
Dartmouth College
Interpreting set theory in second-order arithmetic (second part)

(Continued from Sep 26)

Oct 24
Seth Harris
Dartmouth College
Reverse mathematics of Menger's Theorem
Oct 28
New England Recursion and Definability Seminar (NERDS)

At Wellesley College (Wellesley, MA)

François G. Dorais (Dartmouth College), Rachel Epstein (Harvard University), Tyler Markkanen (Manhattan College), Russell Miller (Queens College, CUNY).

Nov 7
Marcia Groszek
Dartmouth College
First-order axioms and second-order arithmetic