Abstract. According to an analogy to quasi-Fuchsian groups, we investigate the topological and combinatorial structures of Lyubich and Minsky's affine and hyperbolic 3-laminations associated with hyperbolic and parabolic quadratic maps.We begin by showing that hyperbolic rational maps in the same hyperbolic component have quasi-isometrically the same 3-laminations. This gives a good reason to regard the main cardioid of the Mandelbrot set as an analogue of the Bers slices in the quasi-Fuchsian space. Then we describe the topological and combinatorial changes of laminations associated with hyperbolicto-parabolic degenerations (and parabolic-to-hyperbolic bifurcations) of quadratic maps. For example, the differences between the structures of the quotient 3-laminations of Douady's rabbit, the Cauliflower, and z → z 2 are described.The descriptions employ a new method of tessellation inside the filled Julia set introduced in Part I [Ergodic Theory Dynam. Systems 29 (2009)
IntroductionAs an analogue of the hyperbolic 3-orbifolds associated with Kleinian groups, Lyubich and Minsky [LM] introduced hyperbolic orbifold 3-laminations associated with rational maps. For a rational map f :C →C, there exist three kinds of laminations A f , H f , and M f as follows:• The affine lamination A f , a Riemann surface lamination with leaves isomorphic to C or its quotient orbifold.• The H 3 -lamination H f , a hyperbolic 3-lamination with leaves isomorphic to H 3 or its quotient orbifold. (This is a 3D-extension of the affine lamination of f .)As a Kleinian group acts onC and H 3 , there is a natural homeomorphic and leafwise-isomorphic actionf on A f and H f induced from that of f . In particular, the action is properly discontinuous on H f . The third lamination is:• The quotient 3-lamination M f := H f /f , whose leaves are hyperbolic 3-orbifolds.In addition, we have the Fatou-Julia decomposition F f J f = A f of the affine lamination. As a Kleinian group acts on the complement of the limit set properly discontinuously,f acts on F f properly discontinuously. Hence the quotient F f /f forms a Riemann surface lamination and we regard it as the conformal boundary of M f . In this paper we say the quotientLyubich and Minsky applied analogous arguments on rigidity theorems of hyperbolic 3-orbifolds to the hyperbolic 3-laminations, and showed a rigidity result of rational maps that have no recurrent critical points or parabolic points [LM, Theorem 9.1]. However, even for hyperbolic quadratic maps like z 2 − 1 or Douady's rabbit, the precise structure of their laminations have not been investigated. (See the questions in [LM, §10].) Moreover, even for the simplest parabolic quadratic map z 2 + 1/4 ("the Cauliflower") whose 3-lamination has a cuspidal part, its structure had not been precisely known. The aim of this paper is to give a method to describe the topological and combinatorial changes of laminations associated with the motion of parameter c of z 2 + c from one hyperbolic component to another via parabolic parameters. In part...