3 papers
gr-qc2025
Null fluid gravitational fields on Kerr manifolds and optical lifts of Sasaki structures
Masoud Ganji, Cristina Giannotti, Andrea Spiro
Building on the characterisation in [C. D. Hill, J. Lewandowski and P. Nurowski, Indiana Univ. Math. J. 57 (2008), 3131--3176] of 4-dimensional Lorentzian metrics adapted to an opt…
math.DG2024
Einstein manifolds with optical geometries of Kerr type
Masoud Ganji, Cristina Giannotti, Gerd Schmalz +1
We classify the Ricci flat Lorentzian -manifolds satisfying three particular conditions, encoding and combining some crucial features of the Kerr metrics and the Robinson-Trautm…
math.DG2023
The Levi-Civita connections of manifolds with prescribed optical geometries
Dmitri V. Alekseevsky, Masoud Ganji, Gerd Schmalz +1
We explicitly derive the Christoffel symbols in terms of adapted frame fields for the Levi-Civita connection of a Lorentzian -manifold , equipped with a prescribed optic…