Density of cusps in a cubic parameter boundary
v1.3 research notesFor $f_\lambda(z)=\lambda z^2+z^3$, let $U$ be the parameter component where both finite critical points lie in the immediate basin of zero. Prove tha...
Jordan boundary of a cubic parameter component
v1.3 research notesFor $f_\lambda(z)=\lambda z^2+z^3$, let $U$ be the parameter component where both finite critical points lie in the immediate basin of zero. Prove tha...
Uniform geometry in complex renormalization
v1.3 research notesLet $f_i(z)=z^2+c_i$ range over finitely many critically periodic quadratic polynomials, let $g_n$ be the iterated tuning $f_1\vdash\cdots\vdash f_n$,...
Taylor-coefficient regularity of a Siegel conjugacy
v1.3 research notesFor $P_\rho'(z)=\lambda(1-z)^\rho$, $P_\rho(0)=0$, let $h$ linearize the Siegel disk and write $h'(\zeta)/(1-h(\zeta))=\sum_{\nu\ge0}a_\nu\zeta^\nu$. ...
Arc in a Cremer Julia set
v1.3 research notesFor $P_\alpha(z)=z^2+e^{2\pi i\alpha}z$ with a Cremer fixed point at $0$, is there an arc in its Julia set joining $0$ to its preimage $-e^{2\pi i\alp...
Topological model for a Cremer Julia set
v1.3 research notesGive a plausible topological model for the Julia set of a Cremer polynomial....
Computer picture of a Cremer Julia set
v1.3 research notesProduce a reliable computer picture of the Julia set of a Cremer polynomial....
Lebesgue ergodicity on a spherical Julia set
v1.3 research notesIf $J(f)=\widehat{\mathbb C}$, is $f$ ergodic for Lebesgue measure? At least, does it have at most $2\deg f-2$ ergodic components?...
Invariant line fields on Julia sets
v1.3 research notesAre Lattès maps the only rational maps having measurable invariant line fields on their Julia sets?...
Accessibility of positive-exponent boundary points
v1.3 research notesIn the setting of Przytycki Problem 1.1, is every $x\in\partial U$ with $\liminf_{n\to\infty}n^{-1}\log|(f^n)'(x)|>0$ accessible from $U$?...
Unbounded Jacobian cocycles and singularity
v1.3 research notesFor which positive-entropy invariant measures $m$ does failure of uniform $L^2(m)$ boundedness of the sums of $\log\operatorname{Jac}_m f-\kappa\log|f...
Bounded Jacobian cocycles and absolute continuity
v1.3 research notesFor which positive-entropy invariant measures $m$ does uniform $L^2(m)$ boundedness of the sums of $\log\operatorname{Jac}_m f-\kappa\log|f'|$, where ...
Boundary theorems for geometric coding trees
v1.3 research notesWhich theorems about boundary behavior of Riemann maps have analogues for geometric coding trees?...
Representative transcendental entire dynamics
v1.3 research notesFind a collection of representative examples of transcendental entire maps whose dynamics may serve as models for general phenomena....
Newton dynamics for entire functions
v1.3 research notesDescribe the dynamics of Newton's method when applied to broad natural classes of transcendental entire functions....
An orbit converging to an irrationally indifferent fixed point
v1.3 research notesUnder the hypotheses of Eremenko–Lyubich Question 2, can even a single orbit converge to $z_0$?...
Degenerate-flow limits of bad Newton polynomials
v1.3 research notesCall a polynomial bad if its Newton map has an attracting cycle that is not a root. Prove that every bad degree-$d$ polynomial $f_1$ belongs to a one-...
Local connectivity of quadratic Julia sets
v1.3 research notesFor $P_c(z)=z^2+c$ with connected Julia set, characterize the parameters $c$ for which $J(P_c)$ is locally connected....
Lift-family criterion for finite kneading data
v1.3 research notesFind a general property of a lifting family that guarantees convergence of the real Thurston algorithm for every periodic or preperiodic kneading sequ...
Lift-family criterion for arbitrary kneading data
v1.3 research notesFind a general property of a lifting family that guarantees convergence of the real Thurston algorithm for arbitrary kneading sequences....
Boundary fixed points in rank-zero Hénon components
v1.3 research notesIn the rank-zero case, if the limiting map on an invariant stable component is constant with value $x_0\in\partial U$, prove that one eigenvalue at $x...
Herman-ring retracts for Hénon maps
v1.3 research notesCan the subsequential limit map on an invariant stable component of a polynomial diffeomorphism of $\mathbb C^2$ be a retraction onto a Herman ring or...
Products involving Herman rings as stable components
v1.3 research notesIn the rank-two case for a polynomial diffeomorphism of $\mathbb C^2$, can an invariant stable component be a product of two Herman rings, or a produc...
Density of hyperbolic rational maps
v1.3 research notesFor every degree $d$, prove that expanding (hyperbolic, Axiom A) maps are dense in the spaces $\operatorname{Rat}_d$ of rational maps and $\operatorna...
Haken-type decomposition for rational maps
v1.3 research notesDevelop an analogue of the Haken decomposition for geometrically finite rational maps. In particular, if the Julia set is disconnected, can the map be...