3 papers
math.DG2025
A local Lorentzian Ferrand-Obata theorem for conformal vector fields
Sorin Dumitrescu, Charles Frances, Karin Melnick +2
For a conformal vector field on a closed, real-analytic, Lorentzian manifold we prove that the flow is locally isometric -- that it preserves a metric in the conformal class on a n…
math.DG2017
Topology of automorphism groups of parabolic geometries
C. Frances, K. Melnick
We prove for the automorphism group of an arbitrary parabolic geometry that the and topologies coincide, and the group admits the structure of a Lie group in thi…
math.DG2012
About pseudo-Riemannian Lichnerowicz conjecture
Charles Frances
We construct the first known examples of compact pseudo-Riemannian manifolds having an essential group of conformal transformations, and which are not conformally flat. Our example…