A5001562423- Pulsars and Gravitational Waves Research
- Gamma-ray bursts and supernovae
- Cosmology and Gravitation Theories
- Astrophysical Phenomena and Observations
- Dark Matter and Cosmic Phenomena
- Geophysics and Gravity Measurements
- Adaptive optics and wavefront sensing
- Black Holes and Theoretical Physics
- Geophysics and Sensor Technology
- Particle Accelerators and Free-Electron Lasers
- Scientific Research and Discoveries
- High-pressure geophysics and materials
- Computational Physics and Python Applications
- Statistical and numerical algorithms
- Astrophysics and Cosmic Phenomena
- Galaxies: Formation, Evolution, Phenomena
- History and Developments in Astronomy
- Model Reduction and Neural Networks
- Atomic and Subatomic Physics Research
- Cold Atom Physics and Bose-Einstein Condensates
- Advanced Frequency and Time Standards
- Space exploration and regulation
- Statistical Mechanics and Entropy
- Radio Astronomy Observations and Technology
- Seismic Imaging and Inversion Techniques
Johns Hopkins University
2023-2025
Massachusetts Institute of Technology
2018-2023
Moscow Institute of Thermal Technology
2022
Kavli Institute for Particle Astrophysics and Cosmology
2019
Chinese University of Hong Kong
2017-2018
Santa Maria Nuova Hospital
2014
This Horizon Study describes a next-generation ground-based gravitational-wave observatory: Cosmic Explorer. With ten times the sensitivity of Advanced LIGO, Explorer will push astronomy towards edge observable universe ($z \sim 100$). The goals this are to describe and evaluate design concepts for Explorer; plan United States' leadership in astronomy; envisage role international effort build "Third-Generation" (3G) observatory network that make discoveries transformative across astronomy,...
With several dozen binary black hole events detected by LIGO-Virgo to date and many more expected in the next few years, gravitational-wave astronomy is shifting from individual-event analyses population studies. Using GWTC-2 catalog, we perform a hierarchical Bayesian analysis that for first time combines state-of-the-art astrophysical formation models with of primordial holes (PBHs) constrains fraction putative subpopulation PBHs data. We find this depends significantly on set assumed...
We show how LIGO is expected to detect coalescing binary black holes at $z>1$ that are lensed by the intervening galaxy population. Gravitational magnification, $\ensuremath{\mu}$, strengthens gravitational-wave signals $\sqrt{\ensuremath{\mu}}$ without altering their frequencies, which if unrecognized leads an underestimate of event redshift and hence overestimate mass. High magnifications can be reached for binaries, because region intense emission during coalescence so small...
We present a detailed investigation into the properties of GW170729, gravitational wave with most massive and distant source confirmed to date. employ an extensive set waveform models, including new improved models that incorporate effect higher-order modes which are particularly important for systems. find no indication spin-precession, but inclusion in results estimate mass ratio $(0.3-0.8)$ at 90\% credible level. Our updated measurement excludes equal masses also lead data being more...
Gravitational waves emitted by coalescing compact objects carry information about the spin of individual bodies. However, with present detectors only mass-weighted combination components along orbital angular momentum can be measured accurately. This quantity, effective ${\ensuremath{\chi}}_{\mathrm{eff}}$, is conserved up to at least second post-Newtonian order. The distribution ${\ensuremath{\chi}}_{\mathrm{eff}}$ values from a population detected binaries, and in particular whether this...
Hierarchical analysis of the binary black hole (BBH) detections by Advanced LIGO and Virgo detectors has offered an increasingly clear picture their mass, spin, redshift distributions. Fully understanding formation evolution BBH mergers will require not just characterization these marginal distributions, though, but discovery any correlations that exist between properties BBHs. Here, we hierarchically analyze ensemble BBHs discovered with a model allows for intrinsic mass ratios $q$...
Abstract Third-generation (3G) gravitational-wave detectors will be able to observe binary black hole mergers (BBHs) up a redshift of ∼30. This gives unprecedented access the formation and evolution BBHs throughout cosmic history. In this paper, we consider three subpopulations originating from different evolutionary channels: isolated in galactic fields, dynamical globular clusters, holes formed Population III (Pop III) stars at very high redshift. Using input population synthesis analyses,...
Clouds of ultralight bosons - such as axions can form around a rapidly spinning black hole, if the hole radius is comparable to bosons' wavelength. The cloud extracts angular momentum from and reduces it characteristic value that depends on boson's mass well spin. Therefore, measurement spin be used reveal or exclude existence bosons. Using holes released by LIGO Virgo in their GWTC-2, we perform simultaneous distribution at formation scalar boson. We find data strongly disfavors range...
The population-level distributions of the masses, spins, and redshifts binary black holes (BBHs) observed using gravitational waves can shed light on how these systems form evolve. Because complex astrophysical processes shaping inferred BBH population, models allowing for correlations among parameters will be necessary to fully characterize sources. We hierarchically analyze population detected by LIGO Virgo with a model between effective aligned spin primary mass redshift. find that width...
The possible existence of primordial black holes in the stellar mass window has received considerable attention because their mergers may contribute to current and future gravitational-wave detections. Primordial hole mergers, together with originating from Population~III stars, are expected dominate at high redshifts ($z\gtrsim 10$). However merger rate density is rise monotonically redshift, while can only occur after birth first stars. Next-generation detectors such as Cosmic...
We search for signatures of gravitational lensing in the binary black hole events detected by Advanced LIGO and Virgo during their first two observational runs. In particular, we look three effects: 1) evidence magnification individual signals due to galaxy lenses, 2) multiple images strong galaxies, 3) wave optics effects point-mass lenses. find no compelling any these observed signals. However, as sensitivities detectors improve future, detecting lensed may become quite likely.
Abstract The existence of primordial black holes (PBHs), which may form from the collapse matter overdensities shortly after Big Bang, is still under debate. Among potential signatures PBHs are gravitational waves (GWs) emitted binary hole (BBH) mergers at redshifts z ≳ 30, where formation astrophysical unlikely. Future ground-based GW detectors, Cosmic Explorer and Einstein Telescope, will be able to observe equal-mass BBH with total mass <mml:math...
Exploring dark matter via observations of extreme astrophysical environments -- defined here as heavy compact objects such white dwarfs, neutron stars, and black holes, well supernovae object merger events has been a major field growth since the last Snowmass process. Theoretical work highlighted utility current near-future observatories to constrain novel parameter space across full mass range. This includes gravitational wave instruments spanning electromagnetic spectrum, from radio...
Ultralight bosons can form clouds around rotating black holes if their Compton wavelength is comparable to the hole size. The boson cloud spins down through a process called superradiance, lowering spin characteristic determined by mass and mass. It has been suggested that measurements of detected ground-based gravitational-wave detectors be used constrain ultralight bosons. Unfortunately, measurement individual often uncertain, resulting in inconclusive results. Instead, we use hierarchical...
Primordial black holes (PBHs) may form from the collapse of matter overdensities shortly after Big Bang. One identify their existence by observing gravitational wave (GW) emissions merging PBH binaries at high redshifts $z\gtrsim 30$, where astrophysical binary (BBHs) are unlikely to merge. The next-generation ground-based GW detectors, Cosmic Explorer and Einstein Telescope, will be able observe BBHs with total masses $\mathcal{O}(10-100)~M_{\odot}$ such redshifts. This paper serves as a...
Abstract A measurement of the history cosmic star formation is central to understanding origin and evolution galaxies. The extremely challenging using electromagnetic radiation: significant modeling required convert luminosity mass, properly account for dust attenuation, example. Here we show how detections gravitational waves from inspiraling binary black holes made by proposed third-generation detectors can be used measure rate (SFR) massive stars with high precision up redshifts ∼10....
Gravitational waves may be one of the few direct observables produced by ultralight bosons, conjectured dark matter candidates that could key to several problems in particle theory, high-energy physics and cosmology. These axionlike particles spontaneously form ``clouds'' around astrophysical black holes, leading potent emission continuous gravitational detected instruments on ground space. Although this scenario has been thoroughly studied, it not yet appreciated both types detector used...
Next-generation ground-based gravitational wave observatories will observe mergers of intermediate-mass black holes (IMBHs) out to high redshift. Such IMBHs can form through runaway tidal encounters in the cores dense stellar clusters. In this paper, we ask if observation a single merger event between two IMBHs, occurring aftermath coalescence clusters which they formed, be used infer properties their host clusters, such as mass, redshift, and half-mass radius. We implement an...
When gravitational waves pass near a gravitating object, they are deflected, or lensed. If the object is massive, such that wavelength of small compared to its size, lensed wave events can be identified when multiple signals detected at different times. However, long, wave-optics diffraction effects will important, and event by looking for frequency-dependent modulations waveform, without having associate signals. For current ground-based detectors observing stellar-mass binary compact...
Abstract The population properties of intermediate-mass black holes remain largely unknown, and understanding their distribution could provide a missing link in the formation supermassive galaxies. Gravitational-wave observations can help fill gap from stellar mass to with masses between ∼100–10 4 M ⊙ . In our work, we propose new method for examining lens populations through lensing statistics gravitational waves, here focusing on inferring number density hierarchical Bayesian inference....
We address two important questions in gravitational-wave astronomy. What is the astrophysical formation scenario leading to black-hole binary mergers? Did some of merging black holes form hierarchically through previous generations Leveraging fast-to-generate simulations from rapster code and a random forest algorithm, we develop pipeline accurately classify most likely generation dynamically formed on an event-by-event basis. test our framework four merger events with features suggesting...
We investigate the ability of current and third-generation gravitational wave (GW) detectors to determine delay time distribution (DTD) binary neutron stars (BNS) through a direct measurement BNS merger rate as function redshift. assume that DTD follows power law with slope $\Gamma$ minimum $t_{\rm min}$, also allow overall formation efficiency per unit stellar mass vary. By convolving cosmic star history, then GW detector capabilities, we explore two relevant regimes. First, for generation...