Indecomposable continua and the Julia sets of polynomial-like mappings

Abstract

Let $f$ be a polynomial-like mapping of the sphere of degree $d \geq 2$. We show that the Julia set $J(f)$ of $f$ cannot be the union of a finite number of proper indecomposable subcontinua. As a corollary, we prove that $J(f)$ is an indecomposable continuum if and only if there exists a prime end of some complementary region of $J(f)$ whose impression is the entire $J(f)$, generalizing a result by Childers, Mayer and Rogers.