Brjuno-Like Functions for nonlinear expanding maps: Fractional Derivatives and Regularity Dichotomies
Cohomological equations appear frequently in dynamical systems. One of the most classical examples is the Livšic equation $$ v(x) = α\circ F(x) - α(x).$$ The existence and regularity of its solutions $α$ is well understood when $F$ is a hyperbolic dynamical system (for instance an expanding map of the circle) and $v$ is a Hölder...