C. E. Koudjinan

activity

20192026

most citedA KAM Theorem for finitely differentiable Hamiltonian systems

11 citations · 25 across the 8 of their papers we have counts for

collaborators

Showing 2021Show all

2 papers · 1 filter

math.DS2021★ 1 cited

Non co-preservation of the $1/2$ & $1/ (2 l + 1)$ -rational caustics along deformations of circles

V. Kaloshin, C. E. Koudjinan

For any given positive integer $l$ , we prove that every plane deformation of a circle which preserves the $1/2$ and $1/ (2 l + 1)$ -rational caustics is trivial i.e. the deformation con…

math.DS2021

On some invariants of Birkhoff billiards under conjugacy

V. Kaloshin, C. E. Koudjinan

In the class of strictly convex smooth boundaries, each of which not having strip around its boundary foliated by invariant curves, we prove that the Taylor coefficients of the "no…

Non co-preservation of the 1/2 & 1/(2l+1)-rational caustics along deformations of circles

On some invariants of Birkhoff billiards under conjugacy

Non co-preservation of the $1/2$ & $1/ (2 l + 1)$ -rational caustics along deformations of circles