Pseudo-monodromy and the Mandelbrot set

We investigate the discontinuity of codings for the Julia set of a quadratic map. To each parameter ray, we associate a natural coding for Julia sets on the ray. Given a hyperbolic component H H of the Mandelbrot set, we consider the codings along the two parameter rays landing on the root point of H H . Our main result describes the discontinuity of these two codings in terms of the kneading sequences of the hyperbolic components which are conspicuous to H H . This result can be interpreted as a solution to the degenerate case of the monodromy action conjecture in the horseshoe locus for the complex Hénon family.