Year: 2011
Type: article
Abstract: Using the theory of Weyl structures, we give a natural generalization of the notion of essential conformal structures and conformal Killing fields to arbitrary parabolic geometries.We show that a parabolic structure is inessential whenever the automorphism group acts properly on the base space.As a corollary of the generalized Ferrand-Obata theorem proved by C. Frances, this proves a generalization of the "Lichnérowicz conjecture" for conformal Riemannian, strictly pseudo-convex CR, and quaternionic/octonionic contact manifolds in positive-definite signature.For an infinitesimal automorphism with a singularity, we give a generalization of the dictionary introduced by Frances for conformal Killing fields, which characterizes (local) essentiality via the so-called holonomy associated to a singularity of an infinitesimal automorphism.
Author: Jesse Alt
Institution: University of the Witwatersrand
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W2144493413