Embeddings into 𝓟(ℕ)/fin and extension of automorphisms
A. Bella, A. Dow, K. P. Hart, M. Hrusak, J. van Mill, P. Ursino (2002)
Fundamenta Mathematicae
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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.