Related papers: Detuning the BSW Effect with Longitudinal String S…
Black holes (BHs) and wormholes (WHs) are characterized by distinct spacetime geometries, whose differences become pronounced close to the central objects. A useful way to probe such differences is via the dynamics of stellar tidal…
Pre--big bang models of inflation based on string cosmology produce a stochastic gravitational wave background whose spectrum grows with decreasing wavelength, and which may be detectable using interferometers such as LIGO. We point out…
Rotating black holes when attached to a cosmic string have their rotational energy extracted leading to a change in its spin and mass. The spin of a black hole can be measured using various methods for an accreting black hole in an X-ray…
Integrability of classical strings in the BTZ black hole enables the construction and study of classical string propagation in this background. We first apply the dressing method to obtain classical string solutions in the BTZ black hole.…
We study the deformation of a long cosmic string by a nearby rotating black hole. We examine whether the deformation of a cosmic string, induced by the gravitational field of a Kerr black hole, may lead to the formation of a loop of cosmic…
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…
Particle emission, in addition to gravitational radiation from cosmic string loops, affects the resulting loop distribution and hence the corresponding observational consequences of cosmic strings. Here we focus on two models in which loops…
We elucidate the feature of gravitational waves (GWs) from binary neutron star merger collapsing to a black hole by general relativistic simulation. We show that GW spectrum imprints the coalescence dynamics, formation process of disk,…
We compute the low energy decay rates of near-extremal three(four) charge black holes in five(four) dimensional N=4 string theory to sub-leading order in the large charge approximation. This involves studying stringy corrections to…
The target-space interpretation of the exact (in $\alpha'$) reflection coefficient for scattering from Euclidean black-hole horizons in classical string theory is studied. For concreteness, we focus on the solvable $SL(2,…
Binary black-hole systems with spins aligned or anti-aligned to the orbital angular momentum provide the natural ground to start detailed studies of the influence of strong-field spin effects on gravitational wave observations of coalescing…
The mass and distance of a binary black hole (BBH) are fundamental parameters to measure in gravitational-wave (GW) astronomy. It is well-known that the measurement is affected by cosmological redshift, and recent works also showed that…
A gravitational wave (GW) signal carries imprints of the properties of its source. The ability to extract source properties crucially depends on our prior knowledge of the signal morphology. Even though binary black hole (BBH) mergers are…
The detection of gravitational waves (GWs) has opened a new window to test the fundamental nature of gravity. We present constraints on the nonstandard propagation of GWs using the spectral siren method applied to binary black hole (BBH)…
We analyze the physical consequences of scattering Hawking radiation emitted in the vicinity of the horizon of a Schwarzschild black hole. The Hawking radiation from the horizon becomes soft at a large distance away from the horizon due to…
It has been known that gravitational waves (GWs) transfer energy to viscous matter through which they propagate, but the effect is too weak to be astrophysically significant. Using linearized perturbations about a Minkowski background, we…
Supermassive black holes at the centers of galaxies occasionally disrupt stars or consume stellar-mass black holes (BHs) that wander too close, producing observable electromagnetic or gravitational wave signals. We examine how mass…
The recent direct detection of gravitational waves (GWs) from binary black hole mergers (2016, Phys. Rev. Lett. 116, no. 6, 061102; no. 24, 241103) opens up an entirely new non-electromagnetic window into the Universe making it possible to…
An accelerating observer sees a thermal bath of radiation at the Hawking temperature which is proportional to the acceleration. Also, in string theory there is a Hagedorn temperature beyond which one cannot go without an infinite amount of…
Cosmic strings that are attached to rapidly spinning black holes can extract significant amounts of rotational energy and angular momentum. Here we study the effect on primordial black holes, which are expected to form with one or more…