Paper detail

Typical orbits of quadratic polynomials with a neutral fixed point: non-Brjuno type

We investigate the quantitative and analytic aspects of the near-parabolic renormalization scheme introduced by Inou and Shishikura in 2006. These provide techniques to study the dynamics of some holomorphic maps of the form $f(z) = e^{2πi α} z + \mathcal{O}(z^2)$, including the quadratic polynomials $e^{2πi α} z+z^2$, for some irrational values of $α$. The main results of the paper concern fine-scale features of the measure-theoretic attractors of these maps, and their dependence on the data. As a bi-product, we establish an optimal upper bound on the size of the maximal linearization domain in terms of the Siegel-Brjuno-Yoccoz series of $α$.