abstract We show that any virtual or welded period of a classical knot $K$ can be realized as a classical period. A direct consequence is that a classical knot admits only finitely many virtual or welded periods.
published in Breadth in contemporary topology, 29--42, Proc. Sympos. Pure Math., 102, Amer. Math. Soc., Providence, RI, 2019 Journal
keywords INVARIANTS Mathematics Nielsen realization Physical Sciences Science & Technology Virtual and welded knots group automorphisms periodic knots