Changing the heights of automorphism towers

Joel David Hamkins, Simon Thomas

Research output: Contribution to journalArticlepeer-review

1 Scopus citations


If G is a centreless group, then τ(G) denotes the height of the automorphism tower of G. We prove that it is consistent that for every cardinal λ and every ordinal α<λ, there exists a centreless group G such that (a) τ(G)=α; and (b) if β is any ordinal such that 1≤β<λ, then there exists a notion of forcing P, which preserves cofinalities and cardinalities, such that τ(G)=β in the corresponding generic extension VP.

Original languageEnglish (US)
Pages (from-to)139-157
Number of pages19
JournalAnnals of Pure and Applied Logic
Issue number1-3
StatePublished - Mar 3 2000

ASJC Scopus subject areas

  • Logic


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