activity
20222026
collaborators

5 papers

math.DS2026

Jet rigidity of Mather's -function and complexified KAM curves holomorphic in potential for analytic standard maps

Mathieu Helfter

Mather's -function associates with each rotation number the least average action carried by an orbit of a twist map. For analytic standard maps in the KAM regime, we prove the f…

math.PR2025

Infinite Dimensional Multifractal Analysis of the Wiener measure

Aihua Fan, Mathieu Helfter

We present a multifractal formalism for measures on infinite dimensional metric spaces, in terms of scales instead of dimensions in the classical multifractal analysis. We prove a…

math.FA2025

Sets with arbitrary Hausdorff and packing scales in infinite dimensional Banach spaces

Mathieu Helfter

For every couple of Hausdorff functions and verifying some mild assumptions, there exists a compact subset of the Baire space such that the -Hausdorff measure an…

math.DS2022

Every diffeomorphism is a total renormalization of a close to identity map

Pierre Berger, Nicolaz Gourmelon, Mathieu Helfter

For any , we show that every diffeomorphism of a manifold of the form is a total renormalization of a -close to identity map…

math.DS2022

Scales

Mathieu Helfter

We introduce the notion of scale to generalize and compare different invariants of metric spaces and their measures. Several versions of scales are introduced such as Hausdorff, pa…