Rotational entropy for annulus endomorphisms
We study how some dynamical properties on a homeomorphism of the annulus affects its rotation set. We also introduce a topological invariant, designated "rotational entropy," that basically measures the rotational complexity of an annulus mapping. © 1991 by Pacific Journal of Mathematics.
Pacific Journal of Mathematics
Botelho, F. (1991). Rotational entropy for annulus endomorphisms. Pacific Journal of Mathematics, 151 (1), 1-19. https://doi.org/10.2140/pjm.1991.151.1