相关论文: Stellar Pulsations excited by a scattered mass
The light-like limit of the Kerr gravitational field relative to a distant observer moving rectilinearly in an arbitrary direction is an impulsive plane gravitational wave with a singular point on its wave front. By colliding particles with…
We identify a new dynamical mechanism for a strong scalar gravitational field effect. To illustrate this mechanism, we investigate the parametric excitation and emission of scalar gravitational waves by a radially pulsating model neutron…
The nonaxisymmetric Ekman flow excited inside a neutron star following a rotational glitch is calculated analytically including stratification and compressibility. For the largest glitches, the gravitational wave strain produced by the…
The orbital dynamics of fast spinning neutron stars encountering a massive Black Hole (BH) with unbounded orbits are investigated using the quadratic-in-spin Mathisson-Papapetrou- Dixon (MPD) formulation. We consider the motion of the…
Gravitational waves are expected to be radiated by supermassive black hole binaries formed during galaxy mergers. A stochastic superposition of gravitational waves from all such binary systems will modulate the arrival times of pulses from…
The prospects for detection of gravitational waves from precessing pulsars have been considered by constructing fully relativistic rotating neutron star models and evaluating the expected wave amplitude $h$ from a galactic source. For a…
Pulsar glitches, i.e. the sudden spin-ups of pulsars, have been detected for most pulsars that we known. The mechanism giving rise to this kind of phenomenon is uncertain, although a large data set has been built. In the framework of…
We employ scattering amplitudes in curved space to model the dynamics of a light probe particle with mass $m$ orbiting in the background spacetime induced by a heavy gravitational source with mass $M$. Observables are organized as an…
The high eccentricities of the known extrasolar planets remain largely unexplained. We explore the possibility that eccentricities are excited in the outer parts of an extended planetary disk by encounters with stars passing at a few…
We propose that when neutron stars in low-mass X-ray binaries accrete sufficient mass and become millisecond pulsars, the interiors of these stars may undergo phase transitions, which excite stellar radial oscillations. We show that the…
The astronomical observations indicate that the universe expands with acceleration and it has a finite event horizon. The recent CMB observations confirm the universe is homogeneous, isotropic and asymptotically flat. The total…
Understanding the coevolution of supermassive black holes and their host galaxies requires tracing their growth over time. Mass measurements of distant black holes have been limited to active nuclei and commonly rely on spatially unresolved…
Black holes are a common feature of the Universe. They are observed as stellar mass black holes spread throughout galaxies and as supermassive objects in their centres. Observations of stars orbiting close to the centre of our Galaxy…
The origin of high-redshift quasars and their supermassive black hole engines is unclear. One promising solution is the collapse of a primordial supermassive star. Observational confirmation of this scenario may be challenging, but a…
We analyze the distribution of stars of arbitrary mass function xi(m) around a massive black hole (MBH). Unless xi is strongly dominated by light stars, the steady-state distribution function approaches a power-law in specific energy…
Maximum gravitational wave emission from binary stars in eccentric orbits occurs near the periastron passage. We show that for a stationary distribution of binary neutron stars in the Galaxy, several high-eccentricity systems with orbital…
Amplitude and phase variability are commonly found in many different types of pulsating stars. This suggests a common, presently unknown physical origin. We have examined the phenomenon in several Delta Scuti stars with extensive data and…
Supermassive black holes and their surrounding dense stellar environments nourish a variety of astrophysical phenomena. We focus on the distribution of stellar-mass black holes around the supermassive black hole and the consequent formation…
An algorithm is described for evolving the phase-space density of stars or compact objects around a massive black hole at the center of a galaxy. The technique is based on numerical integration of the Fokker-Planck equation in…
Nonaxisymmetric, meridional circulation inside a neutron star, excited by a glitch and persisting throughout the post-glitch relaxation phase, emits gravitational radiation. Here, it is shown that the current quadrupole contributes more…