Related papers: Superradiance Constraints from GW231123
Using recent experimental results of detection of gravitational waves from the binary black hole signals by Advanced LIGO and Advanced Virgo, we investigate the propagation of gravitational waves in the context of fourth order gravity…
Ten binary black-hole mergers have already been detected during the first two observing runs of advanced LIGO and Virgo, and many more are expected to be observed in the near future. This opens the possibility for gravitational-wave…
The recently discovered gravitational wave event GW231123 was interpreted as the merger of two black holes with a total mass of 190-265 $M_\odot$, making it the heaviest such merger detected to date. Whilst much of the post-discovery…
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…
The direct detection of gravitational waves by ground-based interferometers opened an unprecedented channel to probe alternative theories of gravitation. Several theories predict a dispersion of the gravitational waves during their…
Black holes can amplify incoming bosonic waves via rotational superradiance, inducing bound states of ultralight bosons around them. This phenomenon has the potential to confine the parameter spaces of new bosons. Axions and axion-like…
Massive black holes (MBHs), with masses in the range 10^3-10^8 Msolar, which merge with a companion black hole of similar mass are expected to be the most powerful source of gravitational radiation in the frequency range probed by LISA. MBH…
The recent LIGO observation of gravitational waves from a binary black hole merger triggered several follow-up searches from both electromagnetic wave as well as neutrino observatories. Since in general, it is expected that all matter has…
We review current challenges in understanding the values and origin of the spins of black holes in binaries. Thanks to recent advances in astrophysical instrumentation, the spins can now be measured using both gravitational waves emitted by…
In this paper, we provide a simple and modern discussion of rotational superradiance based on quantum field theory. We work with an effective theory valid at scales much larger than the size of the spinning object responsible for…
The Advanced LIGO and Virgo collaborations recently detected a gravitational wave event, GW230529\_181500, during the fourth observing run, which is most plausibly attributed to the merger of a neutron star and a black hole. This…
Coalescing massive black hole binaries are powerful emitters of gravitational waves, in the LISA sensitivity range for masses M_BH ~ 10^{4-7} M_sun. According to hierarchical galaxy merger models, binary black holes should form frequently,…
Gravitational waves from compact binary coalescences provide a unique laboratory to test properties of compact objects. As alternatives to the ordinary black holes in general relativity, various exotic compact objects have been proposed.…
Gravitational-wave observations provide a powerful probe of compact objects and strong-field gravity. In this work, we investigate the detectability of binaries containing (sub-)solar-mass black holes and superspinars with current and…
Supermassive black hole binary mergers generate a stochastic gravitational wave background detectable by pulsar timing arrays. While the amplitude of this background is subject to significant uncertainties, the frequency dependence is a…
The merger of two neutron stars will in general lead to the formation of a torus surrounding a black hole whose rotational energy can be tapped to potentially power a short gamma-ray burst. We have studied the merger of equal-mass binaries…
Gravitational wave astronomy has been firmly established with the detection of gravitational waves from the merger of ten stellar mass binary black holes and a neutron star binary. This paper reports on the all-sky search for gravitational…
Magnetic fields surrounding spinning black holes can confine radiation and trigger superradiant instabilities. To investigate this effect, we perform the first fully-consistent linear analysis of the Ernst spacetime, an exact solution of…
Recent observation of Sagittarius A$^*$ (Sgr A$^*$) by the Event Horizon Telescope (EHT) collaboration has uncovered various unanswered questions in black hole (BH) physics. Besides, it may also probe various beyond the Standard Model (BSM)…
GW231123, the most massive binary black hole (BH) merger observed to date, involves component BHs with masses inside the pair-instability mass gap and unusually high spins. This challenges standard formation channels such as classical…