4 papers
Nearly-optimal effective stability estimates around Diophantine tori of Hölder Hamiltonians
Santiago Barbieri, Gerard Farré
We prove that the solutions of Hölder-differentiable Hamiltonian systems, associated to initial conditions in a small ball of radius around a Lagrangian, Diophantine,…
Semi-algebraic Geometry and generic Hamiltonian stability
Santiago Barbieri
The steepness property is a local geometric transversality condition on the gradient of a -function which is fundamental in order to ensure the stability of sufficiently-regul…
Analytic Smoothing and Nekhoroshev estimates for Hölder steep Hamiltonians
Santiago Barbieri, Jean-Pierre Marco, Jessica Elisa Massetti
In this paper we prove the first result of Nekhoroshev stability for steep Hamiltonians in Hölder class. Our new approach combines the classical theory of normal forms in analytic…
Bernstein-Remez inequality for Nash functions: A complex analytic approach
Santiago Barbieri, Laurent Niederman
Consider an open, bounded set , a positive integer and a compact of cardinality strictly greater than . We prove that, for any fu…