Title: The critical renormalization fixed point for commuting pairs of area-preserving maps
Authors: Gianni Arioli and Hans Koch
Abstract:   We prove the existence of the critical fixed point (F,G) for MacKay's renormalization operator for pairs of maps of the plane. The maps F and G commute, are area-preserving, reversible, real analytic, and they satisfy a twist condition.
Paper: Sections 1-7, Section_8.tgz (formatted program source and README file)