%0 Journal Article %T The Hausdorff dimension of the boundary of the Mandelbrot set and Julia sets %A Mitsuhiro Shishikura %J Mathematics %D 1991 %I arXiv %X It is shown that the boundary of the Mandelbrot set $M$ has Hausdorff dimension two and that for a generic $c \in \bM$, the Julia set of $z \mapsto z^2+c$ also has Hausdorff dimension two. The proof is based on the study of the bifurcation of parabolic periodic points. %U http://arxiv.org/abs/math/9201282v1