Automorphisms of $P(omega_1)/Fin$

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Speaker: 
Paul Larson
Institution: 
Miami University, Oxford, Ohio
Time: 
Mon, 10/13/2014 - 4:00pm - 5:30pm
Host: 
Martin Zeman
Location: 
RH 440R

It appears to be an open question whether for every regular uncountable regular $\lambda$, every automorphism of $P(\lambda)/fin$ is trivial on a co-countable set. We will show that a small fragment of Martin's Axiom implies that if $\lambda$ is at most the continuum then every automorphism of $P(\lambda)/fin$ which is trivial on sets of cardinality less than $\lambda$ is trivial.