Videolibrary
RUS  ENG    JOURNALS   PEOPLE   ORGANISATIONS   CONFERENCES   SEMINARS   VIDEO LIBRARY   PACKAGE AMSBIB  
Video Library
Archive
Most viewed videos

Search
RSS
New in collection






International Conference "Analytic Theory of Differential and Difference Equations" Dedicated to the Memory of Andrey Bolibrukh
January 29, 2021 19:30, online, Moscow
 


Geometry of hyperbolic Cauchy–Riemann singularities and KAM-like theory for holomorphic involutions

Laurent Stolovitch

Université de Nice Sophia Antipolis
Video records:
MP4 260.0 Mb
Supplementary materials:
Adobe PDF 305.5 Kb



Abstract: This joint work with Z. Zhao (Nice) is concerned with the geometry of germs of real analytic surfaces in $(\mathbb{C}^2,0)$ having an isolated Cauchy–Riemann (CR) singularity at the origin. These are perturbations of Bishop quadrics. There are two kinds of CR singularities stable under perturbation : elliptic and hyperbolic. Elliptic case was studied by Moser–Webster who showed that such a surface is locally, near the CR singularity, holomorphically equivalent to normal form from which lots of geometric features can be read off.
In this talk we focus on perturbations of hyperbolic quadrics. As was shown by Moser–Webster, such a surface can be transformed to a formal normal form by a formal change of coordinates that may not be holomorphic in any neighborhood of the origin.
Given a non-degenerate real analytic surface $M$ in $(\mathbb{C}^2,0)$ having a hyperbolic CR singularity at the origin, we prove the existence of Whitney smooth family of holomorphic curves intersecting $M$ along holomorphic hyperbolas. This is the very first result concerning hyperbolic CR singularity not equivalent to quadrics.
This is a consequence of a non-standard KAM-like theorem for pair of germs of holomorphic involutions $\{\tau_1,\tau_2\}$ at the origin, a common fixed point. We show that such a pair has large amount of invariant analytic sets biholomorphic to $\{z_1z_2=const\}$ (which is not a torus) in a neighborhood of the origin, and that they are conjugate to restrictions of linear maps on such invariant sets.

Supplementary materials: sildes_mw_hyperbolic_bolibruch.pdf (305.5 Kb)

Language: English
 
  Contact us:
 Terms of Use  Registration to the website  Logotypes © Steklov Mathematical Institute RAS, 2024