3 papers
math.DG2025
Perturbations of Fefferman spaces over CR three-manifolds
Arman Taghavi-Chabert
We introduce a generalisation of Fefferman's conformal circle bundle over a contact Cauchy-Riemann three-manifold. These can be viewed as exact `perturbations' of Fefferman's struc…
math.DG2025
Perturbations of Fefferman spaces over almost CR manifolds
Arman Taghavi-Chabert
We construct a one-parameter family of Lorentzian conformal structures on the canonical circle bundle of a partially integrable contact almost Cauchy-Riemann manifold. This builds…
math.DG2025
Optical geometries
Anna Fino, Thomas Leistner, Arman Taghavi-Chabert
We study the notion of optical geometry, defined to be a Lorentzian manifold equipped with a null line distribution, from the perspective of intrinsic torsion. This is an instance…