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Reza Bahani

Publications and source records attributed to Reza Bahani.

2 recordsLinked to original sources

A Generalized Class of Taub-NUT-Scalar Metrics

We consider a class of three-parameter metrics that was introduced in \cite{azizallahi2024three}. The class of metrics contain Zipoy-Voorhees (ZV) and Fisher-Janis-Newman- Winicour (FJNW) spacetimes at certain values of the parameters. We build an axially symmetric and asymptotically flat spacetime with gravitomagnetic effects by introducing a Newman- Unti-Tamburino (NUT) charge into this class of metrics via the Ehlers transformation. We investigate the physical features of this class of Taub-NUT-scalar (TNS) metrics including gravitational lensing, quasinormal mode (QNM) spectra, and test particle motion. Our results provide fresh insight on how mass, multipole moments, and gravitomagnetic fields behave in the presence of a scalar field and show the effect of the NUT charge on stability of orbits in this class of metrics.

gr-qc

A class of Taub-NUT-scalar metrics via Ehlers transformations

We derive a class of Taub-NUT metrics in the presence of a scalar field (TNS) by using Ernst equations and potential, as well as using Ehlers transformations on the exact solutions that was recently introduced in Azizallahi et al. (Nucl Phys B 998:116414, https://doi.org/10.1016/j.nuclphysb.2023.116414, arXiv:2307.09328 [gr-qc], 2023) and Mirza et al. (Eur Phys J C 83:1161, https://doi.org/10.1140/epjc/s10052-023-12255-7, arXiv:2307.13588 [gr-qc], 2023). Furthermore, we investigate the effective potential, geodesics, topological charge, quasinormal modes (QNMs) and the deflection angle of light in a gravitational lensing for the obtained class of TNS metrics. We also use conformal transformations to generate a new class of exact solutions of the Einstein-conformal-scalar theory by using the obtained TNS solutions as seed metrics. Finally we compare QNMs of the class of exact solutions.

gr-qc