activity
20242026
collaborators

6 papers

math.DG2026

Locally conformally homogeneous Lorentzian spaces

Thomas Leistner, Lilia Mehidi, Abdelghani Zeghib

We study locally conformally homogeneous Lorentzian manifolds of dimension at least , admitting an essential pseudo-group of local conformal transformations. Generalizing a rece…

math.DG2025

On homogeneous plane waves

Malek Hanounah, Lilia Mehidi, Abdelghani Zeghib

Plane waves are a special class of Lorentzian spaces with a parallel null vector field. They are of great importance in Geometry (e.g. Lorentzian holonomy) and in Physics (General…

math.DG2025

On completeness and dynamics of compact Brinkmann spacetimes

Lilia Mehidi, Abdelghani Zeghib

Brinkmann Lorentz manifolds are those admitting an isotropic parallel vector field. We prove geodesic completeness of the compact and also compactly homogeneous Brinkmann spaces. W…

math.DG2025

On completeness of foliated structures, and null Killing fields

Malek Hanounah, Lilia Mehidi

We consider a compact manifold with a foliation , and a smooth affine connection on the tangent bundle of the foliation . W…

math.DG2025

Introduction to Kundt spaces

Lilia Mehidi, Abdelghani Zeghib

This paper provides an introduction to Kundt spaces, clarifying several important properties, many of which are typically scattered across the mathematical literature or presented…

math.DG2024

Topology and Dynamics of compact plane waves

Malek Hanounah, Ines Kath, Lilia Mehidi +1

We study compact locally homogeneous plane waves. Such a manifold is a quotient of a homogeneous plane wave by a discrete subgroup of its isometry group. This quotient is calle…