Accessible Mandelbrot Sets in the Family zn + λ/zn

In this paper we prove the existence of infinitely many accessible Mandelbrot sets in the parameter plane for the family of maps zn + λ/zn when n > 1. These are Mandelbrot sets for which the cusp of the main cardioid touches the outer boundary of the connectedness locus. We show that there is a unique such Mandelbrot set at the landing point of each external ray that is periodic under θ → nθ.