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.