Density of thin film billiard reflection pseudogroup in Hamiltonian symplectomorphism pseudogroup

Fuente: arXiv
Saved in:
Bibliographic Details
Main Author: Glutsyuk, Alexey
Format: Preprint
Published: 2020
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866916951149772800
author Glutsyuk, Alexey
author_facet Glutsyuk, Alexey
contents Reflections from hypersurfaces act by symplectomorphisms on the space of oriented lines with respect to the canonical symplectic form. We consider an arbitrary $C^{\infty}$-smooth hypersurface $γ\subset\mathbb R^{n+1}$ that is either a global strictly convex closed hypersurface, or a germ of hypersurface. We deal with the pseudogroup generated by compositional ratios of reflections from $γ$ and of reflections from its small deformations. In the case, when $γ$ is a global convex hypersurface, we show that the latter pseudogroup is dense in the pseudogroup of Hamiltonian diffeomorphisms between subdomains of the phase cylinder: the space of oriented lines intersecting $γ$ transversally. We prove an analogous local result in the case, when $γ$ is a germ. The derivatives of the above compositional differences in the deformation parameter are Hamiltonian vector fields calculated by Ron Perline. To prove the main results, we find the Lie algebra generated by them and prove its $C^{\infty}$-density in the Lie algebra of Hamiltonian vector fields. We also prove analogues of the above results for hypersurfaces in Riemannian manifolds.
format Preprint
id arxiv_https___arxiv_org_abs_2005_02657
institution arXiv
publishDate 2020
record_format arxiv
spellingShingle Density of thin film billiard reflection pseudogroup in Hamiltonian symplectomorphism pseudogroup
Glutsyuk, Alexey
Dynamical Systems
Symplectic Geometry
37D50, 37J40
Reflections from hypersurfaces act by symplectomorphisms on the space of oriented lines with respect to the canonical symplectic form. We consider an arbitrary $C^{\infty}$-smooth hypersurface $γ\subset\mathbb R^{n+1}$ that is either a global strictly convex closed hypersurface, or a germ of hypersurface. We deal with the pseudogroup generated by compositional ratios of reflections from $γ$ and of reflections from its small deformations. In the case, when $γ$ is a global convex hypersurface, we show that the latter pseudogroup is dense in the pseudogroup of Hamiltonian diffeomorphisms between subdomains of the phase cylinder: the space of oriented lines intersecting $γ$ transversally. We prove an analogous local result in the case, when $γ$ is a germ. The derivatives of the above compositional differences in the deformation parameter are Hamiltonian vector fields calculated by Ron Perline. To prove the main results, we find the Lie algebra generated by them and prove its $C^{\infty}$-density in the Lie algebra of Hamiltonian vector fields. We also prove analogues of the above results for hypersurfaces in Riemannian manifolds.
title Density of thin film billiard reflection pseudogroup in Hamiltonian symplectomorphism pseudogroup
topic Dynamical Systems
Symplectic Geometry
37D50, 37J40
url https://arxiv.org/abs/2005.02657