Embeddings into P(N)/fin and extension of automorphisms
Angelo Bella, Alan S. Dow, Klaas Pieter Hart, Michael Hrušák, Jan VAN MILL, Pietro Ursino · arXiv (Cornell University) · 2001
Given a Boolean algebra B and an embedding e:B -> P(N)/fin we consider the possibility of extending each or some automorphism of B to the whole P(N)/fin. Among other things, we show, assuming CH, that for a wide class of Boolean algebras there are embeddings for which no non-trivial automorphism can be extended.