Work

Permutations on the random permutation

Year: 2014
Type: preprint
Abstract: The random permutation is the Fraïssé limit of the class of finite structures with two linear orders. Answering a problem stated by Peter Cameron in 2002, we use a recent Ramsey-theoretic technique to show that there exist precisely 39 closed supergroups of the automorphism group of the random permutation, and thereby expose all symmetries of this structure. Equivalently, we classify all structures which have a first-order definition in the random permutation.
Language: English
Open Access status: green
OpenAlex ID: W2952656421
Cites: 1
Cited by: 2
Related to: 20