Abstract
We shall study the concept of renormalisation for a family of unicritical correspondences with rational exponents. Lyubich and Shishikura proved (independently) that if a quadratic map has no indifferent cycle and is only finite renormalizable, then its Julia set has measure zero. For non-integer exponents, Siqueira recently proved that the Julia set has Hausdorff dimension d< 2 for param…