Monday, March 30, 20155:00 pmnote new timeSet theory seminarGC 3309

# Harrington’s Principle and remarkable cardinals

## Ralf Schindler

### University of Münster

It is open whether $\Pi^1_1$ determinacy implies the existence of $0^{\#}$ in 3rd order arithmetic, call it $Z_3$. We compute the large cardinal strength of $Z_3$ plus “there is a real $x$ such that every $x$-admissible is an $L$-cardinal.” This is joint work with Yong Cheng.

Notice the unusual day and time.

Ralf Schindler is a professor at the University of Münster. He earned his PhD in 1996 at the University of Bonn and Habilitation in 2001 at Humboldt University of Berlin. He has also held research and teaching positions at UC Berkeley, University of Bonn, and University of Barcelona among others. His research interests include inner model theory, large cardinals, and forcing.