Abstract
We offer a criterion for showing that the automorphism group of an ultrahomogeneous structure is topologically 2-generated and even has a cyclically dense conjugacy class. We then show how finite topological rank of the automorphism group of an ω-categorical structure can go down to reducts. Together, those results prove that a large number of ω-categorical structures that appear in the literature have an automorphism group of finite topological rank. In fact, we are not aware of any ω-categorical structure to which they do not apply (assuming the automorphism group has no compact quotients). We end with a few questions and conjectures.
Original language | English |
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Pages (from-to) | 2011-2043 |
Number of pages | 33 |
Journal | Transactions of the American Mathematical Society |
Volume | 372 |
Issue number | 3 |
DOIs | |
State | Published - 1 Aug 2019 |
Bibliographical note
Publisher Copyright:© 2019 Itay Kaplan and Pierre Simon.