Classification of exotic circles of \(PL_+(S^1)\)
Let \(G\) be a subgroup of the group \(\text{PL}_+(S^1)\) of orientation-preserving piecewise-linear homeomorphisms of the circle \(S^1\). An exotic circle of \(G\) is a subgroup which is topologically conjugate to SO(2) but not conjugate in \(G\) to SO(2). An explicit construction of exotic circles is given and these circles are classified up to PL conjugacy.
scientific article; zbMATH DE number 1100534