A5038513332- Pulsars and Gravitational Waves Research
- Astrophysical Phenomena and Observations
- Adaptive optics and wavefront sensing
- Relativity and Gravitational Theory
- Cosmology and Gravitation Theories
- Black Holes and Theoretical Physics
- Particle Accelerators and Free-Electron Lasers
- Geophysics and Sensor Technology
- Advanced Mathematical Physics Problems
- Gamma-ray bursts and supernovae
- High-pressure geophysics and materials
- Geophysics and Gravity Measurements
- Stochastic Gradient Optimization Techniques
- Distributed Control Multi-Agent Systems
- Electromagnetic Simulation and Numerical Methods
- Genetics, Bioinformatics, and Biomedical Research
- Experimental and Theoretical Physics Studies
- Seismic Waves and Analysis
- Neural Networks and Reservoir Computing
- Scientific Computing and Data Management
- Electromagnetic Scattering and Analysis
- Stability and Controllability of Differential Equations
- Astrophysics and Cosmic Phenomena
- Planetary Science and Exploration
- Numerical methods for differential equations
University of Maryland, College Park
2009-2025
California Institute of Technology
2010-2014
Institut des Hautes Études Scientifiques
2014
Jagiellonian University
2010
Institute of Physics
2010
Czech Academy of Sciences, Institute of Physics
2010
Laboratoire Jacques-Louis Lions
2010
Sorbonne Université
2010
Max Planck Institute for Gravitational Physics
2006-2009
Max Planck Society
2006-2008
Gravitational waves emitted by black-hole binary systems have the highest signal-to-noise ratio in LIGO and Virgo detectors when spins are aligned with orbital angular momentum extremal. For such systems, we extend effective-one-body inspiral-merger-ringdown waveforms to generic mass ratios calibrating them 38 numerical-relativity nonprecessing produced SXS Collaboration. The simulations span from 1 8, spin magnitudes up 98% of extremality, last for 40 60 gravitational-wave cycles. When...
This paper presents a publicly available catalog of 174 numerical binary black-hole simulations following up to 35 orbits. The includes 91 precessing binaries, mass ratios 8:1, orbital eccentricities from few percent $10^{-5}$, spins 98% the theoretical maximum, and radiated energies 11.1% initial mass. We establish remarkably good agreement with post-Newtonian precession spin directions for two new simulations, we discuss other applications this catalog. Formidable challenges remain: e.g.,...
Oscillations of black hole spacetimes exhibit divergent behavior near the bifurcation sphere and spatial infinity. In contrast, these oscillations remain regular when evaluated event horizon null The hyperboloidal approach provides a natural framework to bridge regions smoothly, resulting in geometric regularization time-harmonic oscillations, known as quasinormal modes (QNMs). This review traces development QNMs asymptotically flat spacetimes, emphasizing both physical motivation recent...
We provide an in-depth investigation of quasinormal-mode oscillations Kerr black holes with nearly extremal angular momenta. first discuss in greater detail the two distinct types quasinormal mode frequencies presented a recent paper (arXiv:1212.3271). One set modes, that we call "zero-damping modes", has vanishing imaginary part limit, and exists for all corotating perturbations (i.e., modes azimuthal index m being nonnegative). The other (the "damped modes") retains finite decay rate even...
A useful choice of gauge when including null infinity in the computational domain is scri-fixing, that is, fixing spatial coordinate location infinity. This allows us to avoid introduction artificial timelike outer boundaries numerical calculations. We construct manifestly stationary scri-fixing coordinates explicitly on Minkowski, Schwarzschild and Kerr spacetimes.
The Numerical–Relativity–Analytical–Relativity (NRAR) collaboration is a joint effort between members of the numerical relativity, analytical relativity and gravitational-wave data analysis communities. goal NRAR to produce numerical-relativity simulations compact binaries use them develop accurate templates for LIGO/Virgo Collaboration in detecting signals extracting astrophysical information from them. We describe results first stage project, which focused on producing an initial set...
Black hole perturbation theory is typically studied on time surfaces that extend between the bifurcation sphere and spatial infinity. From a physical point of view, however, it may be favorable to employ future event horizon null This framework resolves problems regarding representation quasinormal mode eigenfunctions construction short-ranged potentials for equations in frequency domain.
We discuss the properties of effective-one-body (EOB) multipolar gravitational waveform emitted by nonspinning black-hole binaries masses $\ensuremath{\mu}$ and $M$ in extreme-mass-ratio limit $\ensuremath{\mu}/M=\ensuremath{\nu}\ensuremath{\ll}1$. focus on transition from quasicircular inspiral to plunge, merger, ringdown. compare EOB a Regge-Wheeler-Zerilli computed using hyperboloidal layer method extracted at null infinity. Because keeps track analytically most phase differences early...
We compute and analyze the gravitational waveform emitted to future null infinity by a system of two black holes in large mass ratio limit. consider transition from quasi-adiabatic inspiral plunge, merger, ringdown. The relative dynamics is driven leading order ratio, 5PN-resummed, effective-one-body (EOB), analytic radiation reaction. To waveforms we solve Regge-Wheeler-Zerilli equations time-domain on spacelike foliation which coincides with standard Schwarzschild region including motion...
Gravitational self-force theory is the leading approach for modeling gravitational wave emission from small mass-ratio compact binaries. This method perturbatively expands metric of binary in powers mass ratio. The source perturbations depends on orbital configuration, calculational approach, and order perturbative expansion. These sources fall into three broad classes: (i) distributional, (ii) worldtube, (iii) unbounded support. latter, particular, important emerging second-order (in ratio)...
General relativity, as a diffeomorphism-invariant theory, allows the description of physical phenomena in wide variety coordinate systems. In presence boundaries, such event horizons and null infinity, time coordinates must be carefully adapted to global causal structure spacetime ensure computationally efficient description. Horizon-penetrating is used describe dynamics infalling matter radiation across horizon, while hyperboloidal study propagation toward idealized observer at infinity....
We consider an approach to the hyperboloidal evolution problem based on Einstein equations written for a rescaled metric.It is shown that conformal scale factor can be freely prescribed priori in terms of coordinates wellposed initial value such location null infinity independent time coordinate.With appropriate choice single gauge source function each formally singular attains regular limit at infinity.The suggested could beneficial numerical relativity both wave extraction and outer...
We study the horizon absorption of gravitational waves in coalescing, circularized, nonspinning black-hole binaries. The horizon-absorbed fluxes a binary with large mass ratio ($q=1000$) obtained by numerical perturbative simulations are compared an analytical, effective-one-body (EOB) resummed expression recently proposed. method employs linear ratio, EOB-resummed radiation reaction, and Regge-Wheeler-Zerilli formalism for wave extraction. Hyperboloidal layers employed solution equations to...
We present a new approach to solve the 2+1 Teukolsky equation for gravitational perturbations of Kerr black hole. Our relies on horizon penetrating, hyperboloidal foliation spacetime and spatial compactification. In particular, we framework waveform generation from point-particle perturbations. Extensive tests time domain implementation in code {\it Teukode} are presented. The can efficiently deliver waveforms at future null infinity. As first application method, compute inspiraling...
We present two methods to include the asymptotic domain of a background spacetime in null directions for numerical solutions evolution equations so that both radiation extraction problem and outer boundary are solved. The first method is based on geometric conformal approach, second coordinate approach. apply these case massless scalar wave equation Kerr spacetime. Our designed allow existing codes reach radiative zone by including future infinity computational with relatively minor...
A compact object moving in curved spacetime interacts with its own gravitational field. This leads to both dissipative and conservative corrections the motion, which can be interpreted as a self-force acting on object. The original formalism describing this relied heavily Green function of linear differential operator that governs perturbations. However, because global calculation functions nontrivial black-hole spacetimes has been an open problem until recently, alternative methods were...
Stars or small solar-sized black holes plunge into supermassive at the center of galaxies thousands and millions light years from us. One important way to study these catastrophic events is by numerical simulations. A new computational technique for unbounded domains remarkably improves efficiency accuracy such
The detection of gravitational waves and the extraction physical information from them requires prediction accurate waveforms to be used in template banks. For that purpose, accuracy effective-one-body (EOB) has been improved over last years by calibrating numerical-relativity (NR) waveforms. So far, calibration employed a handful NR with total length $\ensuremath{\sim}30$ cycles, being limited computational cost simulations. Here, we address outstanding problem stability EOB respect...
We investigate the asymptotic behavior of spherically symmetric solutions to scalar wave and Yang–Mills equations on a Schwarzschild background. The studies demonstrate astrophysical relevance null infinity in predicting radiation signals for gravitational detectors show how test fields unbounded domains black hole spacetimes can be simulated conveniently by numerically solving hyperboloidal initial value problems.
We study gravitational perturbations of Schwarzschild spacetime by solving a hyperboloidal initial value problem for the Bardeen–Press equation. Compactification along surfaces in scri-fixing gauge allows us to have access waveform at null infinity general setup. argue that this approach leads more accurate and efficient calculation radiation signal than common where timelike outer boundary is introduced. The method can be generalized Kerr using Teukolsky
We study linear gravitational perturbations of Schwarzschild spacetime by solving numerically Regge–Wheeler–Zerilli equations in a time domain using hyperboloidal surfaces and compactifying radial coordinate. stress the importance including asymptotic region computational studies radiation. The approach should be helpful wide range applications employing black hole perturbation theory.
We present the first numerical construction of scalar Schwarzschild Green function in time-domain, which reveals several universal features wave propagation black hole spacetimes. demonstrate trapping energy near photon sphere and confirm its exponential decay. The trapped wavefront propagates through caustics resulting echoes that propagate to infinity. arrival times decay rate these caustic are consistent with along null geodesics large l-limit quasinormal modes. show four-fold singularity...
The Cauchy horizon inside a perturbed Kerr black hole develops an instability that transforms it into curvature singularity. We solve for the linearized Weyl scalars $\psi_0$ and $\psi_4$ scalar $R_{\alpha\beta\gamma\delta}R^{\alpha\beta\gamma\delta}$ along outgoing null rays approaching in interior of holes using Teukolsky equation, compare our results with those found perturbation analysis. Our corroborate previous analysis result at its early parts evolves deformationally-weak, null,...