Related papers: Accessing the axion via compact object binaries
We analyze the dynamics and observational signatures of axion clouds formed via the superradiant instability around primordial black holes, focusing on the mass range $10^{14}-10^{18}$ kg where the latter may account for all the dark…
The axion, as a leading dark matter candidate, is the target of many ongoing and proposed experimental searches based on its coupling to photons. Ultralight axions that couple to photons can also cause polarization rotation of light, which…
Mergers of black-hole binaries are expected to release large amounts of energy in the form of gravitational radiation. However, binary evolution models predict merger rates too low to be of observational interest. In this paper we explore…
The LIGO and Virgo detectors have directly observed gravitational waves from mergers of pairs of stellar-mass black holes, along with a smaller number of mergers involving neutron stars. These observations raise the hope that compact object…
The localization of stellar-mass binary black hole mergers using gravitational waves is critical in understanding the properties of the binaries' host galaxies, observing possible electromagnetic emission from the mergers, or using them as…
It has recently been suggested that the presence of a plenitude of light axions, an Axiverse, is evidence for the extra dimensions of string theory. We discuss the observational consequences of these axions on astrophysical black holes…
Supermassive black hole binaries are the strongest gravitational wave sources in the universe. The systems most likely to be observed with pulsar timing arrays (PTAs) will have particularly high masses ($\gtrsim 10^9 M_\odot$), long periods…
In this thesis we consider the data analysis problem of detecting gravitational waves emitted by inspiraling binary systems. Detection of gravitational waves will open a new window on the Universe enabling direct detection of systems such…
Measurements of the spin of stellar mass black holes (BHs) are now possible both through LIGO observations of binary BH mergers and for BHs in X-ray binary systems. The spins of BHs as inferred from LIGO observations suggest that BH spins…
The detection of a sub-solar mass black hole could yield dramatic new insights into the nature of dark matter and early-Universe physics, as such objects lack a traditional astrophysical formation mechanism. Gravitational waves allow for…
We analyze the distinguishability of populations of coalescing binary neutron stars, neutron-star black-hole binaries, and binary black holes, whose gravitational-wave signatures are expected to be observed by the advanced network of…
A rotating black hole can be clouded by light bosons via superradiance, and thus acquire an atom-like structure. If such a gravitational atom system is companioned with a pulsar, the pulsar can trigger transitions between energy levels of…
The LIGO-Virgo-KAGRA Collaboration has detected over one hundred compact binary mergers in gravitational waves, but the formation history of these binaries remains an open question. Finding the host galaxies of these mergers will provide…
Boson stars have attracted much attention in recent decades as simple, self-consistent models of compact objects and also as self-gravitating structures formed in some dark-matter scenarios. Direct detection of these hypothetical objects…
The observation of gravitational-wave signals from merging black-hole binaries enables direct measurement of the properties of the black holes. An individual observation allows measurement of the black-hole masses, but only limited…
[ABRIDGED] We study supermassive black hole binary mergers driven by angular momentum loss to small-scale gas discs. Such binaries form after major galaxy mergers, but their fate is unclear since hardening through stellar scattering becomes…
When formed through dynamical interactions, stellar-mass binary black holes may retain eccentric orbits ($e>0.1$ at 10 Hz) detectable by ground-based gravitational-wave detectors. Eccentricity can therefore be used to differentiate…
Pulsar timing is a promising technique for detecting low frequency sources of gravitational waves. Historically the focus has been on the detection of diffuse stochastic backgrounds, such as those formed from the superposition of weak…
When binary black holes are embedded in a gaseous environment, a rotating disk surrounding them, the so-called circumbinary disk, will be formed. The binary exerts a gravitational torque on the circumbinary disk and thereby the orbital…
Ultralight boson clouds can form around black holes in binaries through superradiance, and undergo resonant level transitions at certain orbit frequencies. In this work, we investigate the gravitational waves emitted by the clouds during…