Regularity of calibrated sub-actions for circle expanding maps and Sturmian optimization

2021/05/22 by Gao, Rui
#Dynamical Systems (math.DS) #FOS: Mathematics

paper · doi:10.48550/arxiv.2105.10767

Abstract

In this short and elementary note, we study some ergodic optimization problems for circle expanding maps. We first make an observation that if a function is not far from being convex, then its calibrated sub-actions are closer to convex functions in certain effective way. As an application of this simple observation, for circle doubling map, we generalize a result of Bousch saying that translations of the cosine function are uniquely optimized by Sturmian measures. Our argument follows the mainline of Bousch's original proof, while the technical part is simplified by the observation mentioned above, and no numerical calculation is needed.

Related

• Typicality of periodic optimization over an expanding circle map
• Low complexity of optimizing measures over an expanding circle map
• An iterative process for approximating subactions
• Ergodic maximization problem for expanding maps with differentiable observables
• Dynamical obstruction to the existence of continuous sub-actions for\n interval maps with regularly varying property