Centralizers in the full transformation semigroup.
The authors study centralizers of elements in the full transformation semigroup on an arbitrary set. The main result is a rather technical criterion for a transformation to belong to the centralizer of another transformation, given in terms of connected components of the action graph. The results simplifies a bit in some special cases, namely, for transformations on finite sets, for idempotents and for injective transformations. The last section of the paper is a list of several open problems in the area.
scientific article; zbMATH DE number 6147881
scientific article