The failure of the uncountable non-commutative Specker Phenomenon

Saharon Shelah*, Lutz Strüngmann

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

3 Scopus citations

Abstract

Higman proved in 1952 that every free group is non-commutatively slender, that is, for a free group G and for a homomorphism h from the free complete product xωℤ of countably many copies of ℤ into G, there exists a finite subset F ⊆ ω and a homomorphism h̄: *Fℤ → G such that h = h̄pF, where pF is the natural map from xωℤ into *Fℤ. Because of the corresponding phenomenon for abelian groups this is called the non-commutative Specker Phenomenon. In the present paper we shall show that Higman's result fails if one passes from countable to uncountable and thereby answer a question posed by K. Eda. In particular, we will see that, for an uncountable cardinal λ and for non-trivial groups Gx (α ∈ λ), there are 2 homomorphisms from the free complete product of the groups Gx into the integers.

Original languageEnglish
Pages (from-to)417-426
Number of pages10
JournalJournal of Group Theory
Volume4
Issue number4
DOIs
StatePublished - 2001

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