3 papers
gr-qc2026
Closed and broken electromagnetic orbits in Kerr--Newman spacetime
Erasmo Caponio, Giulio Sanzeni, Stefan Suhr
We study future-pointing timelike solutions of the Lorentz force equation in the sub-extremal Kerr--Newman spacetime, with special attention to the time-machine region $\mathfrak T…
gr-qc2025
Geodesic causality in Kerr spacetimes with
Giulio Sanzeni, Karim Mosani
The analytic extension of the Kerr spacetimes into the negative radial region contains closed causal curves for any non-zero rotation parameter and mass parameter . Furtherm…
gr-qc2024
Nonexistence of closed timelike geodesics in Kerr spacetimes
Giulio Sanzeni
The Kerr-star spacetime is the extension over the horizons and in the negative radial region of the Kerr spacetime. Despite the presence of closed timelike curves below the inner h…