A5052460594- Pulsars and Gravitational Waves Research
- Astrophysical Phenomena and Observations
- Black Holes and Theoretical Physics
- Experimental and Theoretical Physics Studies
- Cosmology and Gravitation Theories
- Geophysics and Sensor Technology
- Gamma-ray bursts and supernovae
- Relativity and Gravitational Theory
- Astrophysics and Cosmic Phenomena
- Geophysics and Gravity Measurements
- Radio Astronomy Observations and Technology
- Particle Accelerators and Free-Electron Lasers
- Particle physics theoretical and experimental studies
- High-pressure geophysics and materials
- Mathematical and Theoretical Analysis
- Computational Physics and Python Applications
- Numerical methods for differential equations
- Seismic Imaging and Inversion Techniques
- Solar and Space Plasma Dynamics
- Superconducting Materials and Applications
- Quantum and Classical Electrodynamics
- Sports Dynamics and Biomechanics
- Atomic and Subatomic Physics Research
- Seismology and Earthquake Studies
- Medical Imaging Techniques and Applications
University of Southampton
2015-2025
Kyoto University
2010
Max Planck Institute for Gravitational Physics
2001-2004
Max Planck Society
2001-2004
Brownsville Public Library
2004
Technion – Israel Institute of Technology
1999-2002
Captures of stellar-mass compact objects (COs) by massive ($\sim 10^6 M_\odot$) black holes (MBHs) are potentially an important source for LISA, the proposed space-based gravitational-wave (GW) detector. The orbits inspiraling COs highly complicated; they can remain rather eccentric up until final plunge, and display extreme versions relativistic perihelion precession Lense-Thirring orbital plane. strongest capture signals will be ~10 times weaker than LISA's instrumental noise, but in...
The advanced interferometer network will herald a new era in observational astronomy. There is very strong science case to go beyond the detector and build detectors that operate frequency range from 1 Hz-10 kHz, with sensitivity factor ten better amplitude. Such be able probe of topics nuclear physics, astronomy, cosmology fundamental providing insights into many unsolved problems these areas.
The grand challenges of contemporary fundamental physics---dark matter, dark energy, vacuum inflation and early universe cosmology, singularities the hierarchy problem---all involve gravity as a key component. And all gravitational phenomena, black holes stand out in their elegant simplicity, while harbouring some most remarkable predictions General Relativity: event horizons, ergoregions. hitherto invisible landscape Universe is being unveiled before our eyes: historical direct detection...
One of the most exciting prospects for LISA gravitational wave observatory is detection radiation from inspiral a compact object into supermassive black hole. The large parameter space and low amplitude signal make these sources computationally challenging. We outline here first-cut data analysis scheme that assumes realistic computational resources. In context this scheme, we estimate signal-to-noise ratio source requires to pass our thresholds be detected. Combining with an population in...
Inspirals of stellar-mass compact objects (COs) into $\ensuremath{\sim}{10}^{6}{M}_{\ensuremath{\bigodot}}$ black holes are especially interesting sources gravitational waves for the planned Laser Interferometer Space Antenna (LISA). The orbits these extreme-mass-ratio inspirals (EMRIs) highly relativistic, displaying extreme versions both perihelion precession and Lense-Thirring orbital plane. We investigate question whether emitted waveforms can be used to strongly constrain geometry...
This review is concerned with the gravitational self-force acting on a mass particle in orbit around large black hole. Renewed interest this old problem driven by prospects of detecting waves from strongly gravitating binaries extreme ratios. We begin here summary recent advances theory self-interaction curved spacetime, and proceed to survey some ideas computational strategies devised for implementing case orbiting Kerr detail two these methods: (i) standard mode-sum method, which metric...
The innermost stable circular orbit (ISCO) of a test particle around Schwarzschild black hole mass M has (areal) radius r_{isco}=6MG/c;{2}. If the is endowed with micro(<<M), it experiences gravitational self-force whose conservative piece alters location ISCO. Here we calculate resulting shifts Deltar_{isco} and DeltaOmega_{isco} in ISCO's frequency, at leading order ratio micro/M. We obtain, Lorenz gauge, Deltar_{isco}=-3.269(+/-0.003)microG/c;{2}...
We present a numerical code for calculating the local gravitational self-force acting on pointlike particle in generic (bound) geodesic orbit around Schwarzschild black hole. The calculation is carried out Lorenz gauge: For given orbit, we decompose Lorenz-gauge metric perturbation equations (sourced by delta-function particle) into tensorial harmonics, and solve each harmonic using evolution time domain (in $1+1$ dimensions). physical along then obtained via mode-sum regularization. total...
The general relativistic (Mercury-type) periastron advance is calculated here for the first time with exquisite precision in full relativity. We use accurate numerical relativity simulations of spinless black-hole binaries mass ratios 1/8≤m(1)/m(2)≤1 and compare predictions several analytic approximation schemes. find effective-one-body model to be remarkably and, surprisingly, so also self-force theory [replacing m(1)/m(2)→m(1)m(2)/(m(1)+m(2))(2)]. Our results can inform a universal...
[Abridged] This review surveys the theory of gravitational self-force in curved spacetime and its application to two-body problem extreme-mass-ratio regime. We first lay relevant formal foundation, describing rigorous derivation equation self-forced motion using matched asymptotic expansions other ideas. then progress that has been achieved numerically calculating physical effects astrophysical scenario a compact object inspiralling into (rotating) massive black hole. highlight way which,...
We present results from calculations of the orbital evolution in eccentric binaries nonrotating black holes with extreme mass-ratios. Our inspiral model is based on method osculating geodesics, and first to incorporate full gravitational self-force (GSF) effect, including conservative corrections. The GSF information encapsulated an analytic interpolation formula numerical data for over a thousand sample geodesic orbits. assess importance corrections waveform models gravitational-wave searches.
We compute the conservative piece of gravitational self-force (GSF) acting on a particle mass ${m}_{1}$ as it moves along an (unstable) circular geodesic orbit between innermost stable and light ring Schwarzschild black hole ${m}_{2}\ensuremath{\gg}{m}_{1}$. More precisely, we construct function ${h}_{uu}^{R,L}(x)\ensuremath{\equiv}{h}_{\ensuremath{\mu}\ensuremath{\nu}}^{R,L}{u}^{\ensuremath{\mu}}{u}^{\ensuremath{\nu}}$ (related to Detweiler's gauge-invariant ``redshift'' variable), where...
Using a recently presented numerical code for calculating the Lorenz-gauge gravitational self-force (GSF), we compute $O(m)$ conservative correction to precession rate of small-eccentricity orbits particle mass $m$ moving around Schwarzschild black hole $\mathsf{M}\ensuremath{\gg}m$. Specifically, study gauge-invariant function $\ensuremath{\rho}(x)$, where $\ensuremath{\rho}$ is defined as part dimensionless ratio...
We study conservative finite-mass corrections to the motion of a particle in bound (eccentric) strong-field orbit around Schwarzschild black hole. assume particle's mass $\mu$ is much smaller than hole $M$, and explore post-geodesic $O(\mu/M)$. Our analysis uses numerical data from recently developed code that outputs Lorenz-gauge gravitational self-force (GSF) acting on along eccentric geodesic. First, we calculate $O(\mu/M)$ correction periastron advance orbit, as function...
It is known that a near-extremal Kerr black hole can be spun up beyond its extremal limit by capturing test particle. Here we show overspinning always averted once backreaction from the particle's own gravity properly taken into account. We focus on nonspinning, uncharged, massive particles thrown in along equatorial plane and work first-order self-force approximation (i.e., include all relevant corrections to acceleration through linear order ratio, assumed small, between energy hole's...
We study the scenario in which a massive particle is thrown into rapidly rotating Kerr black hole an attempt to spin it up beyond its extremal limit, challenging weak cosmic censorship. work black-hole perturbation theory, and focus on nonspinning, uncharged particles sent equatorial orbits. first identify complete parameter-space region overspinning occurs when backreaction effects from particle's self-gravity are ignored. find, particular, that can be achieved only with infinity....
Black holes are unique among astrophysical sources: they the simplest macroscopic objects in Universe, and extraordinary terms of their ability to convert energy into electromagnetic gravitational radiation. Our capacity probe nature is limited by sensitivity our detectors. The LIGO/Virgo interferometers gravitational-wave equivalent Galileo's telescope. first few detections represent beginning a long journey exploration. At current pace technological progress, it reasonable expect that...
We compare numerical self-force results and analytical fourth-order post-Minkowskian (PM) calculations for hyperbolic-type scattering of a point-like particle carrying scalar charge $Q$ off Schwarzschild black hole, showing remarkably good agreement. Specifically, we numerically compute the angle including full $O(Q^2)$ scalar-field term (but ignoring gravitational self-force), with expressions obtained in PM framework using scattering-amplitude methods. This example provides nontrivial,...
We present a method for calculating the self-force (the ``radiation reaction force'') acting on charged particle moving in strong field orbit black hole spacetime. In this approach, one first calculates contribution to due each multipole mode of particle's field. Then, sum over modes is evaluated, subject certain regularization procedure. Here we develop procedure scalar charge Schwarzschild background, and results its implementation radial trajectories (not necessarily geodesic).
We present a practical method for calculating the local gravitational self-force (often called "radiation-reaction force") pointlike particle orbiting Schwarzschild black hole. This is an implementation of mode-sum regularization, in which one first calculates (finite) contribution to force due each individual multipole mode perturbation, and then applies certain regularization procedure sum. Here we give values all "regularization parameters" required implementing this procedure, any...
We calculate the gravitational self force acting on a pointlike particle of mass $\mu$, set in circular geodesic orbit around Schwarzschild black hole. Our calculation is done Lorenz gauge: For given orbital radius, we first solve directly for Lorenz-gauge metric perturbation using numerical evolution time domain; then compute (finite) back-reaction from each multipole modes perturbation; Finally, apply ``mode sum'' method to obtain total, physical force. The {\em temporal} component (which...
Captures of compact objects (COs) by massive black holes (MBHs) in galactic nuclei will be an important source for LISA, the space-based gravitational-wave (GW) detector. However, a large fraction captures not individually resolvable--either because they are too distant, have unfavorable orientation, or many years to go before final plunge--and so constitute ``confusion noise,'' obscuring other types sources. Here we estimate shape and overall magnitude spectrum confusion noise from CO...
Recently, two independent calculations have been presented of finite-mass (``self-force'') effects on the orbit a point mass around Schwarzschild black hole. While both computations are based standard mode-sum method, they differ in several technical aspects, which makes comparison between their results difficult---but also interesting. Barack and Sago [Phys. Rev. D 75, 064021 (2007)] invoke notion self-accelerated motion background spacetime, perform direct calculation local self-force...
We calculate the effect of self-interaction on ``geodetic'' spin precession a compact body in strong-field orbit around black hole. Specifically, we consider angle $\ensuremath{\psi}$ per radian orbital revolution for particle carrying mass $\ensuremath{\mu}$ and $s\ensuremath{\ll}(G/c){\ensuremath{\mu}}^{2}$ circular Schwarzschild hole $M\ensuremath{\gg}\ensuremath{\mu}$. compute through $\mathcal{O}(\ensuremath{\mu}/M)$ perturbation theory, i.e, including correction...