A class of charged and charged-Taub-NUT metrics in the presence of a massless scalar field and some of their astrophysical aspects

TL;DR

This paper introduces a new class of exact Einstein solutions with scalar and dyonic charges, analyzing particle motion, gravitational lensing, and quasi-normal modes to explore their astrophysical implications.

Contribution

It derives generalized charged and NUT metrics with scalar fields and investigates their effects on particle dynamics and light deflection.

Findings

Effective potential for particle motion derived

Scalar and dyonic charges influence light deflection

Quasi-normal modes characterized for these metrics

Abstract

We consider a class of exact solutions to the Einstein equations in the presence of a scalar field, recently introduced in [arXiv:2307.09328, arXiv:2307.13588], and derive their generalized form with dyonic charges using Harrison transformations. For specific parameter values, this class of metrics includes the charged Fisher Janis Newman Winicour (FJNW) and gamma metrics. We then investigate the motion of neutral particles in the background of these metrics and derive the corresponding effective potential. Next, by applying Ehlers transformations, we introduce the NUT parameter into the Reissner Nordstrom metric in the presence of the scalar field. We also examine gravitational lensing, focusing on the effects of dyonic and NUT charges, as well as the scalar field, on the deflection angle of light. Finally, we explore the quasi normal modes associated with this class of metrics.