Speaker: 

Derek Levinson

Institution: 

UCLA

Time: 

Monday, November 27, 2023 - 4:00pm to 5:30pm

Host: 

Location: 

RH 340P

We prove from ZF + AD + DC that there is no sequence of distinct $\Gamma_{1,m}$ sets of length $\aleph_{m+2}$. This is the optimal result for the pointclass $\Gamma_{1,m}$ by earlier work of Hjorth. We also get a bound on the length of sequences of $\Gamma_{2n+1,m}$ sets using the same techniques.