Topological Structures in the Julia Sets of Rational Maps Dynamics of the family of complex maps n F (z) z zn with: Paul Blanchard Toni Garijo Matt Holzer U. Hoomiforgot Dan Look Sebastian Marotta Mark Morabito Monica Moreno Rocha Kevin Pilgrim Elizabeth Russell Yakov Shapiro David Uminsky Three different types of topological objects: 1. Cantor Necklaces A Cantor necklace is a planar set that is homeomorphic to the Cantor middle thirds set with open disks replacing removed intervals. Three different types of topological objects: 1. Cantor Necklaces QuickTime™ and a decompressor are needed to see this picture. dynamical plane n=2 Three different types of topological objects: 1. Cantor Necklaces QuickTime™ and a decompressor are needed to see this picture. dynamical plane n=2 Three different types of topological objects: 1. Cantor Necklaces QuickTime™ and a decompressor are needed to see this picture. dynamical plane n=2 Three different types of topological objects: 1. Cantor Necklaces QuickTime™ and a decompressor are needed to see this picture. QuickTime™ and a decompressor are needed to see this picture. parameter plane dynamical plane n=2 Three different types of topological objects: 2. Mandelpinski Necklaces Infinitely many simple closed curves in the parameter plane that pass alternately through centers of “Sierpinski holes” and centers of baby Mandelbrot sets. Three different types of topological objects: 2. Mandelpinski Necklaces QuickTime™ and a decompressor are needed to see this picture. QuickTime™ and a decompressor are needed to see this picture. parameter plane zoom in n=3 Three different types of topological objects: 3. CanManPinski Trees A tree of Cantor necklaces with Mandelbrot sets interspersed between each branch Three different types of topological objects: 3. CanManPinski Trees QuickTime™ and a decompressor are needed to see this picture. QuickTime™ and a decompressor are needed to see this picture. parameter plane parameter plane n=2 Three different types of topological objects: 3. CanManPinski Trees QuickTime™ and a decompressor are needed to see this picture. QuickTime™ and a decompressor are needed to see this picture. parameter plane parameter plane n=2 Dynamics of F (z) z n zn , z complex and n 2 The Julia set J(F ) is: The closure of the set of repelling periodic points; The boundary of the escaping orbits; The chaotic set. The Fatou set is the complement of J(F ). When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 When 0 , the Julia set is the unit circle But when 0 , the Julia set explodes QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 1/16 When 0 , the Julia set is the unit circle But when 0 , the Julia set explodes QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 1/16 A Sierpinski curve When 0 , the Julia set is the unit circle But when 0 , the Julia set explodes QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 0.01 Another Sierpinski curve When 0 , the Julia set is the unit circle But when 0 , the Julia set explodes QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 F (z) z 2 z2 0.2 Also a Sierpinski curve Sierpinski Curve A Sierpinski curve is any planar set that is homeomorphic to the Sierpinski carpet fractal. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. The Sierpinski Carpet F (z ) z 3 Easy computations: 2n free critical points c 1/2n z3 QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. .036.026i F (z ) z 3 Easy computations: 2n free critical points c 1/2n z3 QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. .036.026i F (z ) z 3 Easy computations: 2n free critical points c 1/2n Only 2 critical values z3 QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. v 2 .036.026i F (z ) z 3 Easy computations: 2n free critical points c 1/2n Only 2 critical values z3 QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. v 2 .036.026i F (z ) z 3 Easy computations: 2n free critical points c 1/2n Only 2 critical values z3 QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. v 2 .036.026i F (z ) z 3 Easy computations: 2n free critical points c 1/2n Only 2 critical values z3 QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. v 2 But really only 1 free critical orbit since the map has 2n-fold symmetry .036.026i F (z ) z 3 Easy computations: is superattracting, so z3 B have immediate basin B mapped n-to-1 to itself. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. .036.026i F (z ) z 3 Easy computations: is superattracting, so z3 B have immediate basin B mapped n-to-1 to itself. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. T 0 is a pole, so have trap door T mapped n-to-1 to B. .036.026i F (z ) z 3 Easy computations: is superattracting, so z3 B have immediate basin B mapped n-to-1 to itself. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. T 0 is a pole, so have trap door T mapped n-to-1 to B. So any orbit that eventually enters B must do so by passing through T. .036.026i The Escape Trichotomy (with Dan Look & David Uminsky) There are three distinct ways the critical orbit can enter B: v B v T J(F ) is a Cantor set J(F ) is a Cantor set of simple closed curves (this case does not occur if n = 2) F (v ) T k J(F ) is a Sierpinski curve QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. parameter plane when n = 3 Case 1: v B J(F ) is a Cantor set QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. parameter plane when n = 3 v B J is a Cantor set J(F ) is a Cantor set QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. parameter plane when n = 3 v B J is a Cantor set J(F ) is a Cantor set QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. parameter plane when n = 3 v B J is a Cantor set J(F ) is a Cantor set QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. parameter plane when n = 3 v B J is a Cantor set J(F ) is a Cantor set QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. parameter plane when n = 3 v B J is a Cantor set J(F ) is a Cantor set QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. parameter plane when n = 3 v B J is a Cantor set J(F ) is a Cantor set QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. parameter plane when n = 3 v B J is a Cantor set J(F ) is a Cantor set QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. parameter plane when n = 3 v B J is a Cantor set J(F ) is a Cantor set QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. parameter plane when n = 3 v B J is a Cantor set J(F ) is a Cantor set QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. parameter plane when n = 3 v B J is a Cantor set J(F ) is a Cantor set QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. parameter plane when n = 3 v B J is a Cantor set J(F ) is a Cantor set QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. parameter plane when n = 3 v B J is a Cantor set J(F ) is a Cantor set Case 2: the critical values lie in T, not B QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. parameter plane when n = 3 QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. parameter plane when n = 3 v T lies in the McMullen domain QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. parameter plane when n = 3 v T J is a Cantor set of simple closed curves lies in the McMullen domain Remark: There is no McMullen domain in the case n = 2. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. parameter plane when n = 3 v T J is a Cantor set of simple closed curves lies in the McMullen domain QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. parameter plane when n = 3 v T J is a Cantor set of simple closed curves lies in the McMullen domain QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. parameter plane when n = 3 v T J is a Cantor set of simple closed curves lies in the McMullen domain QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. parameter plane when n = 3 v T J is a Cantor set of simple closed curves lies in the McMullen domain QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. parameter plane when n = 3 v T J is a Cantor set of simple closed curves lies in the McMullen domain QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. parameter plane when n = 3 v T J is a Cantor set of simple closed curves lies in the McMullen domain Case 3: the critical orbit eventually lands in the trap door. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. parameter plane when n = 3 F (v ) T k lies in a Sierpinski hole QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. parameter plane when n = 3 F (v ) T k J is a Sierpinski curve lies in a Sierpinski hole QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. parameter plane when n = 3 F (v ) T k J is a Sierpinski curve lies in a Sierpinski hole QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. parameter plane when n = 3 F (v ) T k J is a Sierpinski curve lies in a Sierpinski hole QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. parameter plane when n = 3 F (v ) T k J is a Sierpinski curve lies in a Sierpinski hole QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. parameter plane when n = 3 F (v ) T k J is a Sierpinski curve lies in a Sierpinski hole QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. parameter plane when n = 3 F (v ) T k J is a Sierpinski curve lies in a Sierpinski hole QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. parameter plane when n = 3 F (v ) T k J is a Sierpinski curve lies in a Sierpinski hole QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. parameter plane when n = 3 F (v ) T k J is a Sierpinski curve lies in a Sierpinski hole QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. parameter plane when n = 3 F (v ) T k J is a Sierpinski curve lies in a Sierpinski hole QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. parameter plane when n = 3 F (v ) T k J is a Sierpinski curve lies in a Sierpinski hole QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. parameter plane when n = 3 F (v ) T k J is a Sierpinski curve lies in a Sierpinski hole 1. Cantor necklaces in the dynamical and parameter plane The Cantor necklace is homeomorphic to the Cantor middle thirds set with open disks replacing removed intervals. 1. Cantor necklaces in the dynamical and parameter plane QuickTime™ and a decompressor are needed to see this picture. The Cantor necklace is homeomorphic to the Cantor middle thirds set with open disks replacing removed intervals. Julia set n = 2 = -0.23 1. Cantor necklaces in the dynamical and parameter plane QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. The Cantor necklace is homeomorphic to the Cantor middle thirds set with open disks replacing removed intervals. parameter plane n=4 Dynamical plane: n = 2 B T Suppose B and T are disjoint. Dynamical plane: n = 2 1/4 Four critical points Dynamical plane: n = 2 21/2 And two critical values that do not lie in T Dynamical plane: n = 2 The critical lines... Dynamical plane: n = 2 are mapped two-to-one to one of two critical value rays S1 S0 So the sectors S0 and S1 are mapped one-to-one to C - {critical value rays) Dynamical plane: n = 2 I1 I0 And the regions I0 - T and I1 - T are mapped one-to-one to C - B - {critical value rays) Dynamical plane: n = 2 And the regions I0 - T and I1 - T are mapped one-to-one to C - B - {critical value rays) Dynamical plane: n = 2 I1 T I0 So consider the bow-tie I0 T I1 Dynamical plane: n = 2 I1 T I0 Both I0 and I1 are mapped one-to-one over the entire bow-tie I0 T I1 Dynamical plane: n = 2 T So we have a preimage of the bow-tie inside each of I0 and I1 Dynamical plane: n = 2 T Then a second preimage, etc., etc. Dynamical plane: n = 2 T The points whose orbits stay in I0 I1 form a Cantor set, and the preimages of T give the adjoined disks. Dynamical plane: n = 2 QuickTime™ and a decompressor are needed to see this picture. The points whose orbits stay in I0 I1 form a Cantor set, and the preimages of T give the adjoined disks. Cantor Necklaces in the Parameter Plane F (z) z 2 c = 1/4 v = 2 1/2 z2 F(v) = 1/4 + 4 D = {| || < 1, Re() < 0} D For each D, have a Cantor set of points inside I1 I1 ... :. ... . . . . T I0 For each D, have a Cantor set of points inside I1 Let zs() be the point in the Cantor set with itinerary s I1 ... :. ... . . . . zs() T I0 For each D, have a Cantor set of points inside I1 Let zs() be the point in the Cantor set with itinerary s zs() depends analytically on and continuously on s I1 ... :. ... . . . . zs() T I0 For each D, have a Cantor set of points inside I1 Let zs() be the point in the Cantor set with itinerary s zs() depends analytically on and continuously on s and zs() lies in the half-disk H given by |z| < 2, Re(z) < 0 I1 ... :. ... . . . . zs() H T I0 So have an analytic map zs() that takes D into H zs() D H So have an analytic map zs() that takes D into H Have another map G() = F(v) = 1/4 + 4 which maps D over a larger half disk containing H zs() G() D H So have an analytic map zs() that takes D into H Have another map G() = F(v) = 1/4 + 4 which maps D over a larger half disk containing H But G is invertible. zs() G-1 D H So have an analytic map zs() that takes D into H Have another map G() = F(v) = 1/4 + 4 which maps D over a larger half disk containing H But G is invertible. So G-1(zs()) maps D strictly inside itself. zs() G-1 D H By the Schwarz Lemma, for each itinerary s there is a unique fixed point s for the map G-1(zs()). zs() s G-1 D H By the Schwarz Lemma, for each itinerary s there is a unique fixed point s for the map G-1(zs()). This is a parameter for which G(s) = zs(s), i.e., the second iterate of the critical points lands on a point in the Cantor set portion of the Cantor necklace. zs() s zs(s) G-1 D H So the points s for each s give a Cantor set of points in the parameter plane. zs() s zs(s) G-1 D H So the points s for each s give a Cantor set of points in the parameter plane. Similar arguments involving Böttcher coordinates on and itineraries of preimages of the trap door then append the Sierpinski holes to the necklace. zs() s zs(s) G-1 D H This necklace lies along the negative real axis. QuickTime™ and a decompressor are needed to see this picture. QuickTime™ and a decompressor are needed to see this picture. parameter plane n=2 There are lots of other Cantor necklaces in the parameter planes. QuickTime™ and a decompressor are needed to see this picture. parameter plane n=2 There are lots of other Cantor necklaces in the parameter planes. QuickTime™ and a decompressor are needed to see this picture. parameter plane n=2 There are lots of other Cantor necklaces in the parameter planes. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. parameter plane n=2 There are lots of other Cantor necklaces in the parameter planes. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. parameter plane n=2 When n > 2, get more complicated Cantor webs case n = 3: When n > 2, get more complicated Cantor webs case n = 3: When n > 2, get more complicated Cantor webs case n = 3: When n > 2, get more complicated Cantor webs case n = 3: When n > 2, get more complicated Cantor webs case n = 3: Continue in this way and then adjoin Cantor sets QuickTime™ and a decompressor are needed to see this picture. Dynamical plane QuickTime™ and a decompressor are needed to see this picture. Parameter plane n = 3 QuickTime™ and a decompressor are needed to see this picture. Dynamical plane QuickTime™ and a decompressor are needed to see this picture. Parameter plane n = 3 QuickTime™ and a decompressor are needed to see this picture. Dynamical plane QuickTime™ and a decompressor are needed to see this picture. Parameter plane n = 3 QuickTime™ and a decompressor are needed to see this picture. Dynamical plane QuickTime™ and a decompressor are needed to see this picture. Parameter plane n = 3 QuickTime™ and a decompressor are needed to see this picture. Dynamical plane QuickTime™ and a decompressor are needed to see this picture. Parameter plane n = 3 Cantor webs in the parameter plane QuickTime™ and a decompressor are needed to see this picture. Parameter plane n = 3 Cantor webs in the parameter plane QuickTime™ and a decompressor are needed to see this picture. Parameter plane n = 3 Cantor webs in the parameter plane QuickTime™ and a decompressor are needed to see this picture. Parameter plane QuickTime™ and a decompressor are needed to see this picture. Parameter plane n = 3 Cantor webs in the parameter plane QuickTime™ and a decompressor are needed to see this picture. Parameter plane QuickTime™ and a decompressor are needed to see this picture. Parameter plane n = 3 Cantor webs in the parameter plane QuickTime™ and a decompressor are needed to see this picture. Parameter plane QuickTime™ and a decompressor are needed to see this picture. Parameter plane n = 3 Different Cantor webs when n = 4 QuickTime™ and a decompressor are needed to see this picture. Dynamical plane QuickTime™ and a decompressor are needed to see this picture. Parameter plane n = 4 Part 2: Mandelpinski Necklaces A “Mandelpinski necklace” is a simple closed curve in the parameter plane that passes alternately through k centers of baby Mandelbrot sets and k centers of Sierpinski holes. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. Parameter plane for n = 3 A “Mandelpinski necklace” is a simple closed curve in the parameter plane that passes alternately through k centers of baby Mandelbrot sets and k centers of Sierpinski holes. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. C1 passes through the centers of 2 M-sets and 2 S-holes Easy check: C1 is the circle r = 2-2n/n-1 Parameter plane for n = 3 A “Mandelpinski necklace” is a simple closed curve in the parameter plane that passes alternately through k centers of baby Mandelbrot sets and k centers of Sierpinski holes. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. Parameter plane for n = 3 A “Mandelpinski necklace” is a simple closed curve in the parameter plane that passes alternately through k centers of baby Mandelbrot sets and k centers of Sierpinski holes. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. C2 passes through the centers of 4 M-sets* and 4 S-holes * only exception: 2 centers of period 2 bulbs, not M-sets Parameter plane for n = 3 A “Mandelpinski necklace” is a simple closed curve in the parameter plane that passes alternately through k centers of baby Mandelbrot sets and k centers of Sierpinski holes. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. Parameter plane for n = 3 C3 passes through the centers of 10 M-sets and 10 S-holes A “Mandelpinski necklace” is a simple closed curve in the parameter plane that passes alternately through k centers of baby Mandelbrot sets and k centers of Sierpinski holes. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. Parameter plane for n = 3 C4 passes through the centers of 28 M-sets and 28 S-holes A “Mandelpinski necklace” is a simple closed curve in the parameter plane that passes alternately through k centers of baby Mandelbrot sets and k centers of Sierpinski holes. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. Parameter plane for n = 3 C5 passes through the centers of 82 M-sets and 82 S-holes Theorem: There exist closed curves Cj, j 1,..., surrounding the McMullen domain. Each Cj passes alternately through (n-2)nj-1 +1 centers of baby Mandelbrot sets and centers of Sierpinski holes. Theorem: There exist closed curves Cj, j 1,..., surrounding the McMullen domain. Each Cj passes alternately through (n-2)nj-1 +1 centers of baby Mandelbrot sets and centers of Sierpinski holes. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. Parameter plane for n = 3 C14 passes through the centers of 4,782,969 M-sets and S-holes Theorem: There exist closed curves Cj, j 1,..., surrounding the McMullen domain. Each Cj passes alternately through (n-2)nj-1 +1 centers of baby Mandelbrot sets and centers of Sierpinski holes. C1: 3 holes and M-sets QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. Parameter plane for n = 4 Theorem: There exist closed curves Cj, j 1,..., surrounding the McMullen domain. Each Cj passes alternately through (n-2)nj-1 +1 centers of baby Mandelbrot sets and centers of Sierpinski holes. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. Parameter plane for n = 4 C2: 9 holes and M-sets* C3: 33 holes and M-sets F (z ) z 3 Easy computations: Critical points: 1/2n Prepoles: (-)1/2n z3 QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. .08i F (z ) z 3 Easy computations: All of the critical points and prepoles lie on the “critical circle” 0 : |z| = | | 1/2n z3 0 QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. .08i F (z ) z 3 Easy computations: All of the critical points and prepoles lie on the “critical circle” 0 : |z| = | | 1/2n QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. v z3 0 v which is mapped 2n-to-1 the “critical onto value line” connecting v .08i F (z ) z 3 Easy computations: Any other circle around 0 is mapped n-to-1 to an ellipse whose foci are 2 z3 0 v QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. v .08i F (z ) z 3 Easy computations: Any other circle around 0 is mapped n-to-1 to an ellipse whose foci are 2 z3 0 v QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. v .08i F (z ) z 3 Easy computations: Any other circle around 0 is mapped n-to-1 to an ellipse whose foci are 2 So the exterior of 0 is mapped as an n-to-1 covering of the exterior of the critical value line. z3 0 v QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. v .08i F (z ) z 3 Easy computations: Any other circle around 0 is mapped n-to-1 to an ellipse whose foci are 2 So the exterior of 0 is mapped as an n-to-1 covering of the exterior of the critical value line. Same with the interior of 0. z3 0 v QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. v .08i Now assume that v lies inside the critical circle: v v 0 Warning: this is not a real proof.... Now assume that v lies inside the critical circle: The exterior of 0 is mapped n-to-1 onto the exterior of the critical value is a preimage ray, so there 1 mappedn-to-1 to 0 , v v 0 Now assume that v lies inside the critical circle: The exterior of 0 is mapped n-to-1 onto the exterior of the critical value is a preimage ray, so there 1 mappedn-to-1 to 0 , v v 0 1 Now assume that v lies inside the critical circle: The exterior of 0 is mapped n-to-1 onto the exterior of the critical value is a preimage ray, so there 1 mappedn-to-1 to 0 , then 2 is mapped n-to-1 to 1 , v v 0 1 2 Now assume that v lies inside the critical circle: The exterior of 0 is mapped n-to-1 onto the exterior of the critical value is a preimage ray, so there 1 mappedn-to-1 to 0 , then 2 is mapped n-to-1 to 1 , v and on and on out to B v 0 1 2 B 0 contains 2n critical points and 2n prepoles, so 1 contains 2n2 pre-critical points and pre-prepoles v v 0 1 0 contains 2n critical points and 2n prepoles, so 1 contains 2n2 pre-critical points and pre-prepoles k contains 2nk+1 points that map to the critical points and pre-prepoles under Fk v v 0 1 2 B 0 contains 2n critical points and 2n prepoles, so 1 contains 2n2 pre-critical points and pre-prepoles k contains 2nk+1 points that map to the critical points and pre-prepoles under Fk QuickTime™ and a decompressor are needed to see this picture. n=3 0 contains 2n critical points and 2n prepoles, so 1 contains 2n2 pre-critical points and pre-prepoles k contains 2nk+1 points that map to the critical points and pre-prepoles under Fk QuickTime™ and a decompressor are needed to see this picture. n=3 0 contains 2n critical points and 2n prepoles, so 1 contains 2n2 pre-critical points and pre-prepoles k contains 2nk+1 points that map to the critical points and pre-prepoles under Fk QuickTime™ and a decompressor are needed to see this picture. n=3 As rotates by one turn, these 2nk+1 points on k each rotate by 1/2nk+1 of a turn. v v 0 k As rotates by one turn, these 2nk+1 points on k each rotate by 1/2nk+1 of a turn. Since 1 1n/2 F (v ) 2 n n/2 n 2 2 n n/2 the second iterate of the critical points rotate by 1 - n/2 of a turn v v 0 k As rotates by one turn, these 2nk+1 points on k each rotate by 1/2nk+1 of a turn. Since 1 1n/2 F (v ) 2 n n/2 n 2 2 n n/2 the second iterate of the critical points rotate by 1 - n/2 of a turn, so this point hits exactly (n / 2 1)(2n k 1 ) 1 (n 2)n k 1 preimages of the critical points and prepoles on k 1 v v 0 k The real proof involves the Schwarz Lemma (as before): There is a natural parametrization k ( ) of each k k ( ) v QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. v 0 k The real proof involves the Schwarz Lemma (as before): There is a natural parametrization k ( ) of each k k ( ) v QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. Best to restrict to a “symmetry region” inside the circle C1, so that k ( ) is well-defined. v 0 k Then we have a second map from the parameter plane to the dynamical plane, namely G( ) F (v ) which is invertible on the symmetry sector QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. k ( ) G 1 Best to restrict to a “symmetry region” inside the circle C1, so that k ( ) is well-defined. v v 0 k Then we have a second map from the parameter plane to the dynamical plane, namely G( ) F (v ) which is invertible on the symmetry sector QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. G 1 So consider the composition G 1 ( k ( ) ) a map from a “disk” to itself. k ( ) v v 0 k Schwarz implies that G 1 ( k ( ) ) has a unique fixed point, i.e., a parameter for which the second iterate of the critical point lands on the point k ( ), so this proves the existence of lots of parameters for which the critical orbits are periodic and land on 0. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. G 1 So consider the composition G 1 ( k ( ) ) a map from a “disk” to itself. k ( ) v v 0 k Remarks: 1. This proves the existence of centers of Sierpinski holes and Mandelbrot sets. Producing the entire M-set involves polynomial-like maps; while the entire S-hole involves qc-surgery. Remarks: 1. This proves the existence of centers of Sierpinski holes and Mandelbrot sets. Producing the entire M-set involves polynomial-like maps; while the entire S-hole involves qc-surgery. 2. It is known that each S-hole in the Mandelpinski necklace is also surrounded by infinitely many sub-necklaces, which in turn are surrounded by sub-sub-necklaces, etc. QuickTime™ and a decompressor are needed to see this picture. QuickTime™ and a decompressor are needed to see this picture. n=3 3. CanManPinski Trees A tree of Cantor necklaces with Mandelbrot sets interspersed between each branch QuickTime™ and a decompressor are needed to see this picture. QuickTime™ and a decompressor are needed to see this picture. parameter plane parameter plane n=2 Recall that we have a Cantor necklace in the dynamical plane lying in I0 T I1 I0 I1 Dynamical plane: n = 2 The regions I2 and I3 are mapped one-to-one over I0 T I1, so there are Cantor necklaces in I2 and I3 I2 I0 I1 I3 Dynamical plane: n = 2 The regions I2 and I3 are mapped one-to-one over I0 T I1, so there are Cantor necklaces in I2 and I3 I2 I0 I1 I3 Dynamical plane: n = 2 This necklace is mapped one-to-one onto the original necklace. This necklace is mapped one-to-one onto the original necklace. And so is the bottom necklace Now consider the regions Sj. S1 S0 S2 S3 Now consider the regions Sj. S0 is mapped two-to-one onto S0 S1 S1 S0 S2 S3 Now consider the regions Sj. S0 is mapped two-to-one onto S0 S1 S1 Similarly, S1 S2 S3, S2 S0 S1 and S3 S2 S3 S0 S2 S3 Assuming lies in the upper half plane, the critical values v lie in S0 and S2 (easy check) S1 v S0 S2 -v S3 Assuming lies in the upper half plane, the critical values v lie in S0 and S2 (easy check) So there is a region in S3 mapped one-to-one onto S3. S1 v S0 S2 -v S3 So there is a preimage of this Cantor necklace in S3 S1 v S0 S2 -v S3 So there is a preimage of this Cantor necklace in S3, S1 v S0 S2 -v S3 So there is a preimage of this Cantor necklace in S3, and then another preimage, S1 v S0 S2 -v S3 So there is a preimage of this Cantor necklace in S3, and then another preimage, and so on, yielding infinitely many necklaces eventually mapping to the original necklace. Looking like branches of a tree.... S1 v S0 S2 -v S3 By symmetry, we have similar branches in S1 S1 v S0 S2 -v S3 By symmetry, we have similar branches in S1, S0, S1 S0 S2 S3 By symmetry, we have similar branches in S1, S0, and S2 S1 S0 S2 S3 This produces trees of Cantor necklaces in the dynamical plane This produces trees of Cantor necklaces in the dynamical plane QuickTime™ and a decompressor are needed to see this picture. Assuming is in the upper half plane, we can again use G() = 1/4 + 4 and an appropriate coding of points in the necklace, and then the Schwarz Lemma produces a similar tree in the upper half of the parameter plane. QuickTime™ and a decompressor are needed to see this picture. Symmetry under complex conjugation yields a similar tree in the lower half-plane. QuickTime™ and a decompressor are needed to see this picture. Then polynomial-like map theory produces a Mandelbrot set in each region in between the branches. QuickTime™ and a decompressor are needed to see this picture. Open problems: Can we use these trees to give a complete map of the Sierpinski-hole regions and buried parameters in the parameter planes? Same question for the baby Mandelbrot sets. Using “Yoccoz puzzles,” do these trees allow us to see that the boundary of the parameter plane locus is a simple closed curve? Open problems: Can we use these trees to give a complete map of the Sierpinski-hole regions and buried parameters in the parameter planes? Same question for the baby Mandelbrot sets. Using “Yoccoz puzzles,” do these trees allow us to see that the boundary of the parameter plane locus is a simple closed curve? Would it be better to call these things Cantormandelbrotsierpinski trees? Open problems: Can we use these trees to give a complete map of the Sierpinski-hole regions and buried parameters in the parameter planes? Same question for the baby Mandelbrot sets. Using “Yoccoz puzzles,” do these trees allow us to see that the boundary of the parameter plane locus is a simple closed curve? Would it be better to call these things Cantormandelbrotsierpinski trees? Who the hell is this? Parameter plane (rotated) when n = 2 QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. Other topics: Main cardioid of a buried baby M-set Perturbed rabbit Convergence to the unit disk Major application If lies in the main cardioid of a buried Mandelbrot set, then again the Julia set is a Sierpinski curve. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. n=4 If lies in the main cardioid of a buried Mandelbrot set, then again the Julia set is a Sierpinski curve. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. n=4 If lies in the main cardioid of a buried Mandelbrot set, then again the Julia set is a Sierpinski curve. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. n=4 If lies in the main cardioid of a buried Mandelbrot set, then again the Julia set is a Sierpinski curve. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. A Sierpinski curve, but very different dynamically from the earlier ones. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. n=4 If lies in the main cardioid of a buried Mandelbrot set, then again the Julia set is a Sierpinski curve. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. A Sierpinski curve, but very different dynamically from the earlier ones. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. n=4 If lies in the main cardioid of a buried Mandelbrot set, then again the Julia set is a Sierpinski curve. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. A Sierpinski curve, but very different dynamically from the earlier ones. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. n=4 If lies in the main cardioid of a buried Mandelbrot set, then again the Julia set is a Sierpinski curve. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. A Sierpinski curve, but very different dynamically from the earlier ones. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. n=4 If lies in the main cardioid of a buried Mandelbrot set, then again the Julia set is a Sierpinski curve. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. A Sierpinski curve, but very different dynamically from the earlier ones. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. n=4 If lies in the main cardioid of a buried Mandelbrot set, then again the Julia set is a Sierpinski curve. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. A Sierpinski curve, but very different dynamically from the earlier ones. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. n=4 If lies in the main cardioid of a buried Mandelbrot set, then again the Julia set is a Sierpinski curve. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. A Sierpinski curve, but very different dynamically from the earlier ones. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. n=4 If lies in the main cardioid of a buried Mandelbrot set, then again the Julia set is a Sierpinski curve. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. A Sierpinski curve, but very different dynamically from the earlier ones. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. n=4 If lies in the main cardioid of a buried Mandelbrot set, then again the Julia set is a Sierpinski curve. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. A Sierpinski curve, but very different dynamically from the earlier ones. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. n=4 If lies in the main cardioid of a buried Mandelbrot set, then again the Julia set is a Sierpinski curve. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. A Sierpinski curve, but very different dynamically from the earlier ones. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. n=4 If lies in the main cardioid of a buried Mandelbrot set, then again the Julia set is a Sierpinski curve. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. A Sierpinski curve, but very different dynamically from the earlier ones. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. n=4 QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. A Sierpinski curve, but very different dynamically from the earlier ones. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. n=4 If lies in the main cardioid of a buried Mandelbrot set, then again the Julia set is a Sierpinski curve. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. A Sierpinski curve, but very different dynamically from the earlier ones. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. n=4 Consider the family of maps F (z) z c n zn where c is the center of a hyperbolic component of the Mandelbrot set. Consider the family of maps F (z) z c n zn where c is the center of a hyperbolic component of the Mandelbrot set. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. c 1 QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 Consider the family of maps F (z) z c n zn where c is the center of a hyperbolic component of the Mandelbrot set. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. c .12.75i QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. 0 When 0, the Julia set again expodes. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. When 0, the Julia set again expodes. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. When 0, the Julia set again expodes. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. When 0, the Julia set again expodes. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. When 0, the Julia set again expodes. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. A doubly-inverted Douady rabbit. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. If you chop off the “ears” of each internal rabbit in each component of the original Julia set, then what’s left is another Sierpinski curve (provided that both of the critical orbits eventually escape). QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. The case n = 2 is very different from (and much more difficult than) the case n > 2. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. n=3 QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. n=2 One difference: there is a McMullen domain when n > 2, but no McMullen domain when n = 2 QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. n=3 QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. n=2 One difference: there is a McMullen domain when n > 2, but no McMullen domain when n = 2 QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. n=3 QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. n=2 There is lots of structure when n > 2, but what is going on when n = 2? QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. n=3 QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. n=2 There is lots of structure when n > 2, but what is going on when n = 2? QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. n=3 QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. n=2 There is lots of structure when n > 2, but what is going on when n = 2? QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. n=3 QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. n=2 Also, not much is happening for the Julia sets near 0 when n > 2 QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. n=3 QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. .01 The Julia set is always a Cantor set of circles. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. n=3 QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. .0001 The Julia set is always a Cantor set of circles. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. n=3 QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. .000001 The Julia set is always a Cantor set of circles. There is always a round annulus of some fixed width in the Fatou set, so the Julia set does not converge to the unit disk. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. .000001 But when n = 2, lots of things happen near the origin; in fact, the Julia sets converge to the unit disk as 0 QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. disk-converge n=2 Here’s the parameter plane when n = 2: QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture. Rotate it by 90 degrees: and this object appears everywhere..... QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture.