19 citations · 42 across the 7 of their papers we have counts for
Showing gr-qcShow all
3 papers · 1 filter
gr-qc2022★ 7 cited
Gravitational lensing in Brill spacetimes
Mourad Halla, Volker Perlick
We consider the Brill metric which is an electrovacuum solution to Einstein's field equation. It depends on three parameters, a mass parameter , a NUT parameter and a charge…
gr-qc2021★ 7 cited
A Morse-theoretical analysis of lensing in wormhole spacetimes
Mourad Halla, Volker Perlick
We consider a class of stationary and axisymmetric wormhole spacetimes that is closely related to, but not identical with, the class of Teo wormholes. We fix a point (observati…
gr-qc2020★ 19 cited
Application of the Gauss-Bonnet theorem to lensing in the NUT metric
Mourad Halla, Volker Perlick
We show with the help of Fermat's principle that every lightlike geodesic in the NUT metric projects to a geodesic of a two-dimensional Riemannian metric which we call the optical…