Bernhard Koenig: Different ways to produce non-special omega_2-Aronszajntrees

Week 1, Friday June 19, 11:10-11:35

The consistency strength of "no omega_2-Suslin trees" is still open, but the consistency strength of "no non-special omega_2-Aronszajn trees" is known to be a weakly compact. We discuss some statements in between those two and give some results about special and non-special omega_2-Aronszajn trees respectively. We might also mention some related results if time allows.