preprint-author: 
A. Epstein, L. Keen, and C. Tresser
preprint-title: 
The Set of Maps $F_{a,b}:x \mapsto x+ a+{b\over 2\pi} \sin(2\pi x)$ with any Given Rotation Interval is Contractible.
preprint-abstract: 

Consider the two-parameter family of real analytic maps $F_{a,b}:x \mapsto x+ a+{b\over 2\pi} \sin(2\pi x)$ which are lifts of degree one endomorphisms of the circle. The purpose of this paper is to provide a proof that for any closed interval $I$, the set of maps $F_{a,b}$ whose rotation interval is $I$, form a contractible set.

preprint-year: 
1994