11 citations · 25 across the 8 of their papers we have counts for
10 papers
(Super-)fast convergence rates for Chernoff approximations via centered differences and Richardson extrapolation
Comlan Edmond Koudjinan
We use centered differences to construct Chernoff families and derive even asymptotic expansions for their iterated products. Richardson extrapolation is then used to cancel polyno…
High-order persistence of resonant caustics in perturbed circular billiards
Comlan Edmond Koudjinan, Rafael Ramírez-Ros
We find necessary and sufficient conditions for high-order persistence of resonant caustics in perturbed circular billiards. The main tool is a perturbation theory based on the Bia…
Birkhoff Conjecture for nearly centrally symmetric domains
Vadim Kaloshin, Comlan Edmond Koudjinan, Ke Zhang
In this paper we prove a perturbative version of a remarkable Bialy-Mironov (Ann.Math:389-413(196), 2022) result. They prove non perturbative Birkhoff conjecture for centrally-symm…
Non co-preservation of the & -rational caustics along deformations of circles
V. Kaloshin, C. E. Koudjinan
For any given positive integer , we prove that every plane deformation of a circle which preserves the and -rational caustics is trivial i.e. the deformation con…
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…
V.I. Arnold's "Global" KAM Theorem and geometric measure estimates
L. Chierchia, C. E. Koudjinan
This paper continues the discussion started in [CK19] concerning Arnold's legacy on classical KAM theory and (some of) its modern developments. We prove a detailed and explicit `gl…