Related papers: Orbital and epicyclic frequencies in massive scala…
According to various models, the orbital and the epicyclic frequencies of particles moving on a circular orbit around compact objects are related to the quasi-periodic oscillations observed in the X-ray flux of some pulsars or black hole…
We study the orbital and epicyclic frequencies of particles orbiting around rapidly rotating neutron stars and strange stars in a particular scalar-tensor theory of gravity. We find very large deviations of these frequencies, when compared…
The frequencies of quasi-periodic oscillations around neutron stars are believed to be related to characteristic frequencies in the gravitational fields of the compact objects. In different variability models, these include the Keplerian,…
In the modern era of abundant X-ray detections and the increasing momentum of gravitational waves astronomy, tests of General Relativity in strong field regime become increasingly feasible and their importance for probing gravity cannot be…
Binary pulsar observations and gravitational wave detections seriously constrained scalar-tensor theories with massless scalar field allowing only small deviations from general relativity. If we consider a nonzero mass of the scalar field,…
We study torsional oscillations of neutron stars in the scalar-tensor theory of gravity using the relativistic Cowling approximation. We compute unperturbed neutron star models adopting realistic equations of state for the neutron star's…
We study non-geodesic corrections to the quasicircular motion of charged test particles in the field of magnetized slowly rotating neutron stars. The gravitational field is approximated by the Lense-Thirring geometry, the magnetic field is…
This work explores the dynamic properties of test particles surrounding a distorted, deformed compact object. The astrophysical motivation was to choose such background, which could constitute a more reasonable model of a real situation…
This work presents the dynamic properties of charged test particles influenced by the gravitational and electromagnetic fields. Accordingly, in this work, we concentrate on the static and axially symmetric metric containing two quadrupole…
The external Hartle-Thorne geometry, which describes the space-time outside a slowly-rotating compact star, is characterized by the gravitational mass $M$, angular momentum $J$ and quadrupole moment $Q$ of the star and gives a convenient…
In this article, we try to capture the influence of deviation from standard Kerr black hole spacetime on observed high-frequency quasi-periodic oscillations signal. We explore the dynamics of test particles in the field of rotating compact…
We derive the perturbation equations for relativistic stars in scalar-tensor theories of gravity and study the corresponding oscillation spectrum. We show that the frequency of the emitted gravitational waves is shifted proportionally to…
Unlike general relativity, the scalar gravitational waves can be excited due to the radial oscillations in scalar-tensor gravity. To examine the scalar gravitational waves in scalar-tensor gravity, we derive the evolution equations of the…
Scalar-tensor theories are well studied extensions of general relativity that offer deviations which are yet within observational boundaries. We present the time evolution equations governing the perturbations of a nonrotating scalarized…
We perform the first study of the oscillation frequencies of rapidly rotating neutron stars in alternative theories of gravity, focusing mainly on the fundamental $f$-modes. We concentrated on a particular class of alternative theories -…
Epicyclic frequencies are usually observed in X-ray binaries and constitute a powerful astrophysical mean to probe the strong gravitational field around a compact object. We consider them in the equatorial plane around a general stationary…
We report on numerical calculations of orbital and epicyclic frequencies in nearly circular orbits around rotating neutron stars and strange quark stars. The FPS equation of state was used to describe the neutron star structure while the…
The spectrum of oscillating compact objects can be considerably altered in alternative theories of gravity. In particular, it may be enriched by modes with no counterpart in general relativity, tied to the dynamics of additional degrees of…
The oscillations of the test particles on circular orbits in field of super-extremal charged central object are researched. The formulae for oscillation frequencies are obtained in cases of circular orbits perturbations caused by small…
This paper studies the oscillation properties of relativistic, non-self-gravitating tori in the background of a distorted deformed compact object. This work concentrates on the static and axially symmetric metric containing two quadrupole…