Solving the geodesic equations
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Black hole shadow in a general rotating spacetime obtained through Newman-Janis algorithm Open
The Newman-Janis (NJ) algorithm has been extensively used in the literature\nto generate rotating black hole solutions from nonrotating seed spacetimes. In\nthis work, we show, using various constants of motion, that the null geodesic\nequ…
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Gravitational Wave Glitches in Chaotic Extreme-Mass-Ratio Inspirals Open
The Kerr geometry admits the Carter symmetry, which ensures that the geodesic equations are integrable. It is shown that gravitational waveforms associated with extreme-mass-ratio inspirals involving a nonintegrable compact object display …
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Tidal disruptions by rotating black holes: relativistic hydrodynamics with Newtonian codes Open
We propose an approximate approach for studying the relativistic regime of stellar tidal disruptions by rotating massive black holes. It combines an exact relativistic description of the hydrodynamical evolution of a test fluid in a fixed …
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Geodesics and the magnitude-redshift relation on cosmologically symmetric Finsler spacetimes Open
We discuss the geodesic motion of both massive test particles, following timelike geodesics, and light, following null geodesics, on Finsler spacetimes with cosmological symmetry. Using adapted coordinates on the tangent bundle of the spac…
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Gravitational-wave glitches: Resonant islands and frequency jumps in nonintegrable extreme-mass-ratio inspirals Open
The detection of gravitational waves from extreme-mass-ratio inspirals with upcoming space-borne detectors will allow for unprecedented tests of general relativity in the strong-field regime. Aside from assessing whether black holes are un…
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Wormhole shadows in rotating dust Open
As an extension of our previous work, which investigated the shadows of the Ellis wormhole surrounded by nonrotating dust, in this paper we study wormhole shadows in rotating dust flow. First, we derive steady-state solutions of slowly rot…
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Geodesic equations in the static and rotating dilaton black holes: Analytical solutions and applications Open
In this paper, we consider the timelike and null geodesics around the static\n[GMGHS (Gibbons, Maeda, Garfinkle, Horowitz and Strominger), magnetically\ncharged GMGHS, electrically charged GMGHS] and the rotating (Kerr-Sen\ndilaton-axion) …
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Precisely computing bound orbits of spinning bodies around black holes\n I: General framework and results for nearly equatorial orbits Open
Very large mass ratio binary black hole systems are of interest both as a\nclean limit of the two-body problem in general relativity, as well as for their\nimportance as sources of low-frequency gravitational waves. At lowest order,\nthe s…
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Completing characterization of photon orbits in Kerr and Kerr-Newman metrics Open
Recently, several new characteristics have been introduced to describe null geodesic structure of stationary spacetimes, such as photon regions (PR) and transversely trapping surfaces (TTS). The former are three-dimensional domains confini…
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Numerical relativity in spherical coordinates: A new dynamical spacetime and general relativistic MHD evolution framework for the Einstein Toolkit Open
We present SphericalNR, a new framework for the publicly available Einstein Toolkit that numerically solves the Einstein field equations coupled to the equations of general relativistic magnetohydrodynamic (GRMHD) in a 3+1 split of spaceti…
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Photon trapping in static axially symmetric spacetime Open
Recently, several new characteristics have been introduced to describe null\ngeodesic structure of strong gravitational field, such as photon regions,\ntransversely trapping surfaces and some generalizations. They give an\nalternative and …
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Orbits of light rays in scale-dependent gravity: Exact analytical solutions to the null geodesic equations Open
We study photon orbits in the background of $(1+3)$-dimensional static, spherically symmetric geometries. In particular, we have obtained exact analytical solutions to the null geodesic equations for light rays in terms of the Weierstra{\s…
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Geodesics of the hyperbolically symmetric black hole Open
We carry out a systematic study on the motion of test particles in the region\ninner to the horizon of a hyperbolically symmetric black hole. The geodesic\nequations are written and analyzed in detail. The obtained results are\ncontrasted …
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Constraining black holes with light boson hair and boson stars using epicyclic frequencies and quasiperiodic oscillations Open
Light bosonic fields are ubiquitous in extensions of the Standard Model. Even when minimally coupled to gravity, these fields might evade the assumptions of the black-hole no-hair theorems and give rise to spinning black holes which can be…
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Killing Tensor and Carter Constant for Painlevé–Gullstrand Form of Lense–Thirring Spacetime Open
Recently, the authors have formulated and explored a novel Painlevé–Gullstrand variant of the Lense–Thirring spacetime, which has some particularly elegant features, including unit-lapse, intrinsically flat spatial 3-slices, and some parti…
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Lightlike geodesics and gravitational lensing in the spacetime of an accelerating black hole Open
The C-metric is a solution to Einstein’s vacuum field equation that describes an accelerating black hole. In this paper we discuss the propagation of light rays and the resulting lensing features in this metric. We first solve the lightlik…
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Effective Geometry of the Bardeen Spacetimes: Gravitational Lensing and Frequency Mapping of Keplerian Disks Open
We study the appearance of Keplerian accretion disks in order to demonstrate the influence of the nonlinear electrodynamics (NED) on the gravitational lensing and frequency shifting of the images of the Keplerian disks. We focus our attent…
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GRay2: A General Purpose Geodesic Integrator for Kerr Spacetimes Open
Fast and accurate integration of geodesics in Kerr spacetimes is an important tool in modeling the orbits of stars and the transport of radiation in the vicinities of black holes. Most existing integration algorithms employ Boyer–Lindquist…
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Gravitational birefringence of light in Robertson-Walker cosmologies Open
The spacetime evolution of massless spinning particles in a Robertson-Walker background is derived using the deterministic system of equations of motion due to Papapetrou, Souriau and Saturnini. A numerical integration of this system of di…
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Geodesic motion in Bogoslovsky-Finsler spacetimes Open
International audience
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Gravitational wave of the Bianchi VII universe: particle trajectories,\n geodesic deviation and tidal accelerations Open
For the gravitational wave model based on the type III Shapovalov wave\nspace-time, test particle trajectories and the exact solution of geodesic\ndeviation equations for the Bianchi type VII universe are obtained. Based on\nthe found 4-ve…
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Analytic solutions of the geodesic equation for Reissner-Nordström–(anti–)de Sitter black holes surrounded by different kinds of regular and exotic matter fields Open
The purpose of this study is the derivation of the equation of motion for particles and light in the spacetime of Reissner-Nordstr\"{o}m-(anti-)de Sitter black holes in the background of different kinds of regular and exotic matter fields.…
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Geodesic Model of HF QPOs Tested for Black Holes in Spacetimes Reflecting the Effect of Surrounding Dark Matter Open
Using the simple but robust model of a shell of dark matter (DM) around a Schwarzschild black hole (BH), represented by the mass ratio of the shell and BH Δ M / M , the shell extension Δ r s and its inner radius r s , we study the influenc…
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Raychaudhuri and optical equations for null geodesic congruences with torsion Open
We study null geodesic congruences (NGCs) in the presence of spacetime\ntorsion, recovering and extending results in the literature. Only the highest\nspin irreducible component of torsion gives a proper acceleration with respect\nto metri…
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Geometry optimization speedup through a geodesic approach to internal coordinates Open
We present a new geodesic-based method for geometry optimization in a basis set of redundant internal coordinates. Our method updates the molecular geometry by following the geodesic generated by a displacement vector on the internal coord…
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Analytical effective one-body formalism for extreme-mass-ratio inspirals with eccentric orbits Open
Extreme-mass-ratio inspirals (EMRIs) are among the most important sources for future spaceborne gravitational wave detectors. In this kind of system, compact objects usually orbit around central supermassive black holes on complicated traj…
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Geodesic Vector Fields on a Riemannian Manifold Open
A unit geodesic vector field on a Riemannian manifold is a vector field whose integral curves are geodesics, or in other worlds have zero acceleration. A geodesic vector field on a Riemannian manifold is a smooth vector field with accelera…
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Geodesic flows in a charged black hole spacetime with quintessence Open
\n We investigate the evolution of timelike geodesic congruences, in the background of a charged black hole spacetime surrounded by quintessence. The Raychaudhuri equations for three kinematical quantities namely the expansion scalar, shea…
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A space-time geodesic approach for phase fitted variational integrators Open
The use of space-time geodesic approach of classical mechanics is investigated, in order to derive time adaptive high order phase fitted variational integrators. The proposed technique is employed for systems of which the Lagrangian is of …
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Non-relativistic spinning particle in a Newton-Cartan background Open
We construct the action of a non-relativistic spinning particle moving in a\ngeneral torsionless Newton-Cartan background. The particle does not follow the\ngeodesic equations, instead the motion is governed by the non-relativistic\nanalog…