A5022352473- Pulsars and Gravitational Waves Research
- Astrophysical Phenomena and Observations
- Gamma-ray bursts and supernovae
- Black Holes and Theoretical Physics
- Geophysics and Sensor Technology
- Cosmology and Gravitation Theories
- Seismic Waves and Analysis
- Geophysics and Gravity Measurements
- advanced mathematical theories
- Dark Matter and Cosmic Phenomena
- Mathematical Biology Tumor Growth
- Quantum chaos and dynamical systems
- Cancer Genomics and Diagnostics
- Nonlinear Waves and Solitons
- Magnetic confinement fusion research
- Bayesian Methods and Mixture Models
- Mathematical Analysis and Transform Methods
- Astrophysics and Cosmic Phenomena
- Streptococcal Infections and Treatments
- Cold Atom Physics and Bose-Einstein Condensates
- High-pressure geophysics and materials
- Computational Fluid Dynamics and Aerodynamics
- Stellar, planetary, and galactic studies
- Adaptive optics and wavefront sensing
- Astro and Planetary Science
Perimeter Institute
2024-2025
California Institute of Technology
2019-2024
Alaska Heart and Vascular Institute
2024
Tsinghua University
2016-2019
The gravitational wave strain emitted by a perturbed black hole (BH) ringing down is typically modeled analytically using first-order BH perturbation theory. In this Letter, we show that second-order effects are necessary for modeling ringdowns from merger simulations. Focusing on the strain's (ℓ,m)=(4,4) angular harmonic, presence of quadratic effect across range binary mass ratios agrees with theoretical expectations. We find (4,4) mode's amplitude exhibits scaling fundamental (2,2)...
We present SEOBNRv5HM, a more accurate and faster inspiral-merger-ringdown gravitational waveform model for quasicircular, spinning, nonprecessing binary black holes within the effective-one-body (EOB) formalism. Compared to its predecessor, SEOBNRv4HM, (i) incorporates recent high-order post-Newtonian results in inspiral, with improved resummations, (ii) includes modes $(\ensuremath{\ell},|m|)=(3,2),(4,3)$, addition (2,2), (3,3), (2,1), (4,4), (5,5) already implemented (iii) is calibrated...
The excitation of quadratic quasinormal modes is an important nonlinear phenomenon for a Kerr black hole ringing at specific linear mode. amplitude this second-order effect proportional to the square mode amplitude, with ratio being linked nature hole. Focusing on $(l=m=2,n=0)$ mode, we compute dependency dimensionless spin hole, ranging up 0.99, method applicable more general couplings. Our calculation makes use frequency-domain, Teukolsky equation, which involves two essential steps: (a)...
We investigate quadratic quasinormal mode coupling in black hole spacetime through numerical experiments of single perturbed holes using both relativity and second-order perturbation theory. Focusing on the dominant $\ensuremath{\ell}=|m|=2$ quadrupolar modes, we find good agreement (within $\ensuremath{\sim}10%$) between these approaches, with discrepancies attributed to truncation error uncertainties from fitting. Our results align earlier studies extracting coefficients select binary...
Joint gravitational-wave detections of stellar-mass black-hole binaries by ground- and space-based observatories will provide unprecedented opportunities for fundamental physics astronomy. We present a semianalytic method to estimate multiband event rates combining selection effects ground-based interferometers (like LIGO/Virgo) space missions LISA). forecast the expected number first using information from current LIGO/Virgo data, then through population synthesis simulations binary stars....
We propose two frequency-domain filters to analyze ringdown signals of binary black hole mergers. The first rational filter is constructed based on a set (arbitrary) quasi-normal modes (QNMs) the remnant holes, whereas second full comes from transmissivity holes. can remove corresponding QNMs original time-domain ringdowns, while changing early inspiral in trivial way - merely time and phase shift. After filtering out dominant QNMs, we visualize existence various subdominant effects. For...
There have been debates in the literature about existence of first overtone ringdown GW150914. We develop a novel Bayesian framework to reanalyze data this event, by incorporating new technique, "rational filter" that can clean particular modes from signal. examine GW150914 multiple perspectives. First, we confirm estimates remnant black hole mass and spin are more consistent with those obtained full IMR signal when including at an early stage (right after inferred peak); such improvement...
We formulate a Bayesian framework to analyze ringdown gravitational waves from colliding binary black holes and test the no-hair theorem. The idea hinges on mode cleaning-revealing subdominant oscillation modes by removing dominant ones using newly proposed "rational filters." By incorporating filter into inference, we construct likelihood function that depends only mass spin of remnant hole (no dependence amplitudes phases) implement an efficient pipeline constrain without Markov chain...
A fully relativistic three-dimensional Cauchy-characteristic matching (CCM) algorithm is implemented for physical degrees of freedom in a numerical relativity code spectre. The method free approximations and can be applied to any system. We test the with various scenarios involving smooth data, including propagation Teukolsky waves within flat background, perturbation Kerr black hole wave, injection gravitational-wave pulse from characteristic grid. Our investigations reveal no instabilities...
The ringdown gravitational wave signal arising, e.g., in the final stage of a black hole binary merger, contains important information about properties remnant and can potentially be used to perform clean tests general relativity. However, interpreting signal, particular, when it is loudest, requires understanding role nonlinearities their potential impact on modeling this phase using quasinormal modes. Here, we focus particular nonlinear effect arising from change hole's mass spin due...
We calculate the microlensing event rate and typical time-scales for free-floating planet (FFP) population that is predicted by core accretion theory of formation. The found to be ~$1.8\times 10^{-3}$ stellar population. While time-scale peaks at around 20 days, median FFP events (~0.1 day) much shorter. Our values are significantly smaller than those required explain \cite{Sum+11} result, factors ~13 ~16, respectively. inclusion planets wide separations does not change results...
Abstract Cauchy-characteristic evolution (CCE) is a powerful method for accurately extracting gravitational waves at future null infinity. In this work, we extend the previously implemented CCE system within numerical relativity code SpECTRE by incorporating scalar field. This allows to capture features of beyond-general-relativity theories. We derive contributions equations motion, Weyl computations, Bianchi identities, and balance laws Our algorithm, tested across various scenarios,...
Tidal effects have important imprints on gravitational waves (GWs) emitted during the final stage of coalescence binaries that involve neutron stars (NSs). Dynamical tides can be significant when NS oscillations become resonant with orbital motion; understanding this process is for accurately modeling GW emission from these and extracting information data. In paper, we use semianalytic methods to carry out a systematic study tidal excitation fundamental modes ($f$-modes) spinning NSs in...
We present a numerical-relativity simulation of black hole - neutron star merger in scalar-tensor (ST) gravity with binary parameters consistent the gravitational wave event GW200115. In this exploratory simulation, we consider Damour-Esposito-Farese extension to Brans-Dicke theory, and maximize effect spontaneous scalarization by choosing soft equation state ST theory at edge known constraints. extrapolate waves, including tensor scalar (breathing) modes, future null-infinity. The numerical...
Numerical-relativity surrogate models for both black-hole merger waveforms and remnants have emerged as important tools in gravitational-wave astronomy. While producing very accurate predictions, their applicability is limited to the region of parameter space where numerical-relativity simulations are available computationally feasible. Notably, this excludes extreme mass ratios. We present a machine-learning approach extend validity existing future toward test-particle limit, targeting...
We study the spin and eccentricity evolution of black-hole (BH) binaries that are perturbed by tertiary masses experience Lidov-Kozai (LK) excitation. focus on three aspects. First, we spin-orbit alignment inner binary following approach outlined Antonini et al. [Mon. Not. R. Astron. Soc. 480, L58 (2018)] Liu Lai [Astrophys. J. 863, 68 (2018)], yet allowing spins to have random initial orientations. confirm existence a dynamical attractor drives angle at end LK value given between outer...
Rossby modes (r-modes) of rotating neutron stars can be excited by the gravitomagnetic forces in coalescing binary systems. The previous study Flanagan and Racine [Phys. Rev. D 75, 044001 (2007)] showed that this kind dynamical tide (DT) induce phase shifts 0.1 rad on gravitational waveforms, which is detectable third-generation (3G) detectors. In paper, we impact DT measuring neutron-star parameters era 3G We incorporate two universal relations among star properties predicted different...
We propose a new approach toward reconstructing the late-time near-horizon geometry of merging binary black holes, and computing gravitational-wave echoes from exotic compact objects. A black-hole merger spacetime can be divided by time-like hypersurface into Black-Hole Perturbation (BHP) region, in which space-time approximated homogeneous linear perturbations final Kerr hole, nonlinear region. At late times, boundary between two regions is an infalling shell. The BHP region contains...
We use numerical relativity to study the merger and ringdown stages of ``superkick'' binary black hole systems (those with equal mass antiparallel spins). find a universal way describe current quadrupole gravitational waves emitted by these during stage: (i) The time evolutions are insensitive progenitor's parameters (spins) after being normalized their own peak values. (ii) values, which encode all spin information progenitor, can be consistently fitted formulas inspired post-Newtonian...
We present numerical waveforms of gravitational-wave echoes from spinning exotic compact objects (ECOs) that result binary black hole coalescence. obtain these by solving the Teukolsky equation for $\psi_4$ associated with gravitational waves propagate toward horizon a Kerr spacetime, and process subsequent reflections horizon-going wave surface ECO, which lies right above horizon. The trajectories infalling are modified geodesics, such propagating future null infinity match those merging...
We investigate quadratic quasinormal mode coupling in black hole spacetime through numerical simulations of single perturbed holes using both relativity and second-order perturbation theory. Focusing on the dominant $\ell=|m|=2$ quadrupolar modes, we find good agreement (within $\sim10\%$) between these approaches, with discrepancies attributed to truncation error uncertainties from fitting. Our results align earlier studies extracting coefficients select binary merger simulations, showing...
We numerically investigate the imprints of gravitational radiation-reaction driven changes to a black hole's mass and spin on corresponding ringdown waveform. do so by comparing dynamics perturbed hole evolved with full (nonlinear) versus linearized Einstein equations. As expected, we find that quasinormal mode amplitudes extracted from nonlinear evolution deviate their linear counterparts at third order in initial perturbation amplitude. For perturbations leading change $\sim 5\%$, which is...