Symmetries and Model Theory
Evans, Macpherson & Ivanov (1997) provide a model-theoretic description of the covering maps of cycles.
Tararin (2001, 2001) studies groups of automorphisms of cycles with various transitivity properties. Giraudet & Holland (2002) characterize cycles whose full automorphism groups act freely and transitively. Campero-Arena & Truss (2009) characterize countable colored cycles whose automorphism groups act transitively. Truss (2009) studies the automorphism group of the unique (up to isomorphism) countable dense cycle.
Kulpeshov & Macpherson (2005) study minimality conditions on circularly ordered structures, i.e. models of first-order languages that include a cyclic order relation. These conditions are analogues of o-minimality and weak o-minimality for the case of linearly ordered structures. Kulpeshov (2006, 2009) continues with some characterizations of ω-categorical structures.
Read more about this topic: Cyclic Order
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