Related papers: Relativistic Astrophysics with Resonant Multiple I…
Modelling of gravitational waves from binary black hole inspiral has played an important role in the recent observations of such signals. The late-stage ringdown phase of the gravitational waveform is often associated with the null particle…
The defining feature of a classical black hole is being a perfect absorber. Any evidence showing otherwise would indicate a departure from the standard black-hole picture. Energy and angular momentum absorption by the horizon of a black…
Gravitational-wave data analysis requires a detailed understanding of the highly relativistic, late stages of inspiral of neutron-star and black-hole binaries. A promising method to compute the late inspiral and its emitted waves is…
States of particles with negative energies are considered for the nonrelativistic and relativistic cases. In nonrelativistic case it is shown that the decays close to the attracting center can lead to the situation similar to the Penrose…
A nonrelativistic particle released from rest at the edge of a ball of uniform charge density or mass density oscillates with simple harmonic motion. We consider the relativistic generalizations of these situations where the particle can…
A perturbed black hole emits gravitational radiation, usually termed the ringdown signal, whose frequency and time-constant depends on the mass and spin of the black hole. I investigate the case of a binary black hole merger resulting from…
Black hole-neutron star mergers resulting in the disruption of the neutron star and the formation of an accretion disk and/or the ejection of unbound material are prime candidates for the joint detection of gravitational-wave and…
Relativistic binary pulsars, such as B1534+12 and B1913+16 are characterized by having close orbits with a binary separation of ~ 3 R_\sun. The progenitor of such a system is a neutron star, helium star binary. The helium star, with a…
Extreme mass ratio bursts (EMRBs) have been proposed as a possible source for future space-borne gravitational wave detectors, such as the Laser Interferometer Space Antenna (LISA). These events are characterized by long-period,…
Starting with a post-Newtonian description of compact binary systems, we derive a set of equations that describes the evolution of the orbital angular momentum and both spin vectors during inspiral. We find regions of phase space that…
Chaos is present in most stellar dynamical systems and manifests itself through the exponential growth of small perturbations. Exponential divergence drives time irreversibility and increases the entropy in the system. A numerical…
Quadrupole oscillation modes in stars can resonate with incident gravitational waves (GWs), and grow non-linear at the expense of GW energy. Stars near massive black hole binaries (MBHB) can act as GW-charged batteries, cooling radiatively.…
The construction of ready to use templates for gravitational waves from spinning binaries is an important challenge in the investigation of detectable gravitational wave signals. Here we present a method to evaluate the gravitational wave…
The light deflection of one component of a binary system due to the gravitational field of the other component is investigated. While this relativistic effect has not been observed thus far, the question arises that whether this effect…
Different numbers of self-gravitating particles (in different types of periodic motion) are most likely to generate very different shapes of gravitational waves, some of which, however, can be accidentally almost the same. One such example…
We study a black hole with a blurred mass density instead of a singular one, which is caused by the noncommutativity of 3-space. Depending on its mass, such object has either none, one or two event horizons. It possesses properties, which…
Rotational superradiance generates the amplification of incoming waves of sufficiently low frequency when scattered with a rotating absorbing body. This may be used to discover new \emph{bosonic} particles of mass $m_b$ if the rotating body…
We discuss (3+1) dimensional general relativistic hydrodynamic simulations of close neutron star binary systems. The relativistic field equations are solved at each time slice with a spatial 3-metric chosen to be conformally flat. Against…
The radial velocity method for detecting extra-solar planets relies on measuring the star's wobble around the system's center of mass. Since this is an indirect method, we may ask if there are other dynamical effects that can mimic such…
Sitnikov problem, consisting two close binaries and a third small body is considered, leading to a rapid ejection of the small body from the binaries. This mechanism is proposed as an explanation of jets in many astrophysical systems.…