Mathematical logic seminar - February 25, 2014

Time: 12:00 - 13:20

Room: Wean Hall 7201

Speaker:     Chris Lambie-Hanson    
Department of Mathematical Sciences
Carnegie Mellon University

Title: Jonsson cardinals, partition relations and stationary reflection II


Abstract: I will present a proof that, relative to large cardinal assumptions, it is consistent that there is a singular cardinal mu such that every stationary subset of mu^+ reflects but that there is a stationary subset of mu^+ that does not reflect at ordinals of arbitrarily high cofinality. This answers a question of Eisworth motivated by the study of Jónsson cardinals and square-bracket partition relations and is joint work with James Cummings.