Linear Response for Intermittent Circle Maps
Odaudu Etubi
TL;DR
This work develops a linear response theory for the intermittent circle map by leveraging Baladi–Todd cone techniques to obtain weak differentiability of the SRB measure with respect to parameter changes. Central to the approach is the construction of invariant cones, a random perturbation framework with distortion control, and careful transfer-operator calculus to derive a well-defined derivative formula involving the resolvent $(I-\mathcal L_\alpha)^{-1}$. The authors establish local Lipschitz continuity of the parameter-to-observable map, prove summability of the perturbative terms, and extend results to observables in $L^q$. As an application, they lift regularity to the base dynamics of a solenoid map with intermittency, proving statistical stability of the associated SRB measure under perturbations. The results combine precise control of neutral fixed-point behavior with perturbative spectral analysis, contributing to the understanding of linear response in slowly mixing systems and their skew-product extensions.
Abstract
Using the Cone technique of Baladi and Todd, we show some form of weak differentiability of the SRB measure for the intermittent circle maps, demonstrating linear response in the process. Subsequently, as an application, we lift the regularity from the base dynamics of the solenoid map with intermittency, showing that this family is statistically stable.
