Department of Mathematical Sciences, University of Wisconsin, Milwaukee, Wisconsin 53211 ; Thomas J. Watson Research Center, I.B.M., P.O. Box 218, Yorktown Heights, New York 10598
Abstract:
Let be a circle endomorphism of degree one with exactly two critical points and negative Schwarzian derivative. Assume that there is no real number such that has a unique rotation number equal to . Then the same holds true for any such that stands above in the Farey tree and can be related to it by a path on the tree.