Modular curves, C* algebras, and chaotic cosmology

We make some brief remarks on the relation of the mixmaster universe model of chaotic cosmology to the geometry of modular curves and to noncommutative geometry. In particular we consider a class of solutions with bounded number of cycles in each Kasner era and describe their dynamical properties, which we relate to the noncommutative geometry of a moduli space of such solutions, given by a Cuntz-Krieger C*-algebra.