arXiv subjects

Vitalie Lungu

Publications and source records attributed to Vitalie Lungu.

8 recordsLinked to original sources

arXiv2026

Particle dynamics around an electrically charged Kiselev black hole embedded in quintessence

We introduce and study a new solution describing a static, spherically symmetric and electrically charged black hole embedded in a charged quintessence fluid, which corresponds to an electric generalization of the Kiselev geometry. We derive the effective potential and analyze the various types of orbits followed by charged particles. A special attention is given to circular orbits and their stability. We found that for uncharged particles the periapsis shifts for bounded orbits is always prograde. However, for charged test particles the periapsis shifts can become retrograde in some cases.

gr-qc↗

arXiv2026

Epicyclic motion of charged particles around a weakly magnetized Kiselev black hole

We investigate the motion of charged particles evolving around a magnetized Kiselev black hole, in the weak magnetic field approximation. The effective potential allows us to study the bound motion and the stable circular orbits. We analyze the impact of combined quintessence and magnetic fields on the epicyclic frequencies. Finally, we examine the periapsis shift and gravitational Larmor precession pointing out differences from the Ernst or Kiselev spacetimes.

gr-qc↗

arXiv2025

Accelerating charged and rotating black holes in scalar multipolar universes

Recently, Cardoso and Natario constructed an exact solution of Einstein-scalar field equations that describes a scalar counterpart of the Schwarzschild-Melvin Universe. In fact, this solution belongs to a more general class of solutions described by Herdeiro in [7]. In this work we show how to further generalize these solutions in presence of acceleration, rotation and various charges. More specifically, we describe general accelerating charged rotating black holes with NUT charge in scalar multipolar universes and present some of their properties.

gr-qc↗

arXiv2025

Null geodesics around a magnetized Kiselev black hole

A new magnetically charged Kiselev black hole solution is used to study the null geodesics in this spacetime. We derive the equations of motion for the null geodesics and analyze their properties, including the gravitational lensing effect. The 3D and equatorial plane orbits are discussed, with particular attention given to the effect of quintessence. The deviations from the Ernst black hole provide insights into the potential observational consequences of dark energy in strong gravitational fields.

gr-qc↗

arXiv2025

Charged Particles Orbiting a Magnetized Black Hole Immersed in Quintessential Matter

A new exact magnetized solution describing a Kiselev black hole immersed in a magnetic field is used for studying the dynamics of charged particles. Different types of trajectories are discussed. In the particular case of a weak magnetic field, we employ a first-order perturbative approach to analyze the perturbed circular orbits near the minimum of the effective potential. We obtain an approximate solution for the bounded equatorial trajectory subjected to small radial and latitudinal oscillations. The shape of the trajectory localized near the stable circular orbit depends on the relation between the attractive gravitational force and the repulsive quintessence contribution.

gr-qc↗

arXiv2024

Charged particles in the background of the Kiselev solution in power-Maxwell electrodynamics

In this work we analyze the motion of charged particles in the background of the Kiselev geometry, which is considered here as an exact solution in the context of power-Maxwell electrodynamics. As it is well known, one can use either an electric ansatz or a magnetic one for the nonlinear electromagnetic field. We study the motion of an electrically charged particle for an electrically charged black hole and also for a magnetically charged black hole. In the second case the motion is restricted to Poincaré cones of various angles, as expected.

gr-qc↗

arXiv2024

Charged particles moving around a spherically symmetric dilatonic black hole

For the static spherically symmetric dilatonic black hole described by the Gibbons-Maeda-Garfinkle-Horowitz-Strominger geometry, we analyze the timelike trajectories for electrically charged test particles. Both cases of an electric black hole and a magnetic one are considered. Finally, we are obtaining the solution to the Klein--Gordon equation in terms of Heun confluent functions and the corresponding energy spectrum. A special attention is given to the role of the dilaton parameter.

hep-th↗

arXiv2022

The Kiselev solution in power-Maxwell electrodynamics

In this work we reconsider the solution describing black holes surrounded by a `quintessence'-like fluid. This geometry was introduced by Kiselev in 2003 and its physical source was originally modeled by an anisotropic fluid. We show that the Kiselev geometry is actually an exact solution of the Einstein equations coupled to nonlinear electrodynamics. More specifically, we show that the Kiselev geometry becomes an exact solution in the context of power-Maxwell electrodynamics, using either an electric ansatz or a magnetic one. In both cases the physical source can be modeled by a power-Maxwell Lagrangian, albeit with different powers corresponding to the electric or the magnetic charges. We briefly investigate the motion of charged particles in this geometry. Finally, we give the proper interpretation of the black-hole thermodynamics in this context. Similarly to the Schwarzschild-de Sitter case, we note the presence of the Schottky peaks in the heat capacity, signaling out the possibility of this thermodynamic black hole system to function as a continuous heat machine.

gr-qc↗