Hölder properties of Weierstrass-like solutions of $θ$-twisted cohomological equations
It is proved that bounded solutions of modified ($θ$-twisted) cohomological equations for expanding circle maps are $θ$-Hölder continuous but are not $(θ+γ)$-Hölder continuous for every $γ>0$ at almost every point. This gives new examples of "nonlinear" Weierstrass-like functions for which the optimal \holder exponent at most points is known.