On possible set{theoretical entropies of self{homeomorphisms of a topological space

In the following text, for natural numbers q1; : : : ; qn we prove there exists a topological space X such that fs1q1 + + snqn : s1; : : : ; sn 0g is the collection of all set{theoretical entropies of homeomorphisms like f : X ! X.

کلیدواژه ها:

Disjoint union ، Homeomorphism ، Set{theoretical entropy