A5006054349- Pulsars and Gravitational Waves Research
- Astrophysical Phenomena and Observations
- Cosmology and Gravitation Theories
- Black Holes and Theoretical Physics
- Gamma-ray bursts and supernovae
- Geophysics and Gravity Measurements
- Relativity and Gravitational Theory
- Geophysics and Sensor Technology
- Astrophysics and Cosmic Phenomena
- High-pressure geophysics and materials
- Dark Matter and Cosmic Phenomena
- Galaxies: Formation, Evolution, Phenomena
- Radio Astronomy Observations and Technology
- Scientific Research and Discoveries
- Antenna Design and Optimization
- NMR spectroscopy and applications
- Algebraic and Geometric Analysis
- Earthquake Detection and Analysis
- Particle physics theoretical and experimental studies
Laboratoire Univers et Théories
2012-2023
Université Paris Sciences et Lettres
2017-2023
Centre National de la Recherche Scientifique
2010-2023
Université Paris Cité
2014-2023
Sorbonne Paris Cité
2017-2023
Janssen (France)
2014-2021
Centro Brasileiro de Pesquisas Físicas
2021
Délégation Paris 7
2014-2019
Laboratoire d’études spatiales et d’instrumentation en astrophysique
2018
Institut d'Astrophysique de Paris
2008-2015
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...
The open question of whether a black hole can become tidally deformed by an external gravitational field has profound implications for fundamental physics, astrophysics and gravitational-wave astronomy. Love tensors characterize the tidal deformability compact objects such as astrophysical (Kerr) holes under static field. We prove that all vanish identically Kerr in nonspinning limit or axisymmetric perturbation. In contrast to this result, we show are generically nonzero spinning hole....
We produce gravitational waveforms for nonspinning compact binaries undergoing a quasicircular inspiral. Our approach is based on two-timescale expansion of the Einstein equations in second-order self-force theory, which allows first-principles waveform production tens milliseconds. Although designed extreme mass ratios, our agree remarkably well with those from full numerical relativity, even comparable-mass systems. results will be invaluable accurately modeling extreme-mass-ratio...
We continue a previous work on the comparison between post-Newtonian (PN) approximation and gravitational self-force (SF) analysis of circular orbits in Schwarzschild background. show that numerical SF data contain physical information corresponding to extremely high PN approximations. find knowing analytically determined appropriate parameters helps tremendously allowing be used obtain higher order coefficients. Using standard theory we compute leading 4PN next-to-leading 5PN logarithmic...
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...
Using the main result of a companion paper, in which binding energy circular-orbit nonspinning compact binary system is computed at leading-order beyond test-particle approximation, exact expression effective-one-body (EOB) metric component ${g}_{tt}^{\mathrm{eff}}$ obtained through first order mass ratio. Combining these results with recent gravitational self-force calculation periastron advance for circular orbits Schwarzschild geometry, EOB ${g}_{rr}^{\mathrm{eff}}$ also determined linear...
First laws of black hole mechanics, or thermodynamics, come in a variety different forms. In this paper, from purely post-Newtonian (PN) analysis, we obtain first law for binary systems point masses moving along an exactly circular orbit. Our calculation is valid through 3PN order and includes, addition, the contributions logarithmic terms at 4PN 5PN orders. This point-particle mechanics then derived principles general relativity, analogies are drawn with single cases. Some consequences...
Using the first law of binary black-hole mechanics, we compute binding energy E and total angular momentum J two non-spinning compact objects moving on circular orbits with frequency Omega, at leading order beyond test-particle approximation. By minimizing E(Omega) recover exact shift Schwarzschild innermost stable orbit induced by conservative piece gravitational self-force. Comparing our results for coordinate invariant relation E(J) to those recently obtained from numerical simulations...
The open question of whether a Kerr black hole can become tidally deformed or not has profound implications for fundamental physics and gravitational-wave astronomy. We consider embedded in weak slowly varying, but otherwise arbitrary, multipolar tidal environment. By solving the static Teukolsky equation gauge-invariant Weyl scalar $\psi_0$, by reconstructing corresponding metric perturbation an ingoing radiation gauge, general harmonic index $\ell$, we compute linear response to field....
The problem of a compact binary system whose components move on circular orbits is addressed using two different approximation techniques in general relativity. post-Newtonian (PN) involves an expansion powers $v/c\ensuremath{\ll}1$, and most appropriate for small orbital velocities $v$. perturbative self-force analysis requires extreme mass ratio ${m}_{1}/{m}_{2}\ensuremath{\ll}1$ the binary. A particular coordinate-invariant observable determined as function frequency these approximations....
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...
Inspiralling and coalescing binary black holes are promising sources of gravitational radiation. The orbital motion gravitational-wave emission such system can be modeled using a variety approximation schemes numerical methods in general relativity: post-Newtonian (PN) formalism, hole perturbation theory (BHP), relativity (NR) simulations the effective one-body (EOB) model. We review recent work at multiple interfaces these analytical techniques, emphasizing use coordinate-invariant...
For a self-gravitating particle of mass $\ensuremath{\mu}$ in orbit around Kerr black hole $M\ensuremath{\gg}\ensuremath{\mu}$, we compute the $\mathcal{O}(\ensuremath{\mu}/M)$ shift frequency innermost stable circular equatorial due to conservative piece gravitational self-force acting on particle. Our treatment is based Hamiltonian formulation dynamics terms geodesic motion certain locally defined effective smooth spacetime. We recover same result using so-called first law binary...
A model of dark matter and energy based on the concept gravitational polarization is investigated. We propose an action in standard general relativity for describing, at some effective or phenomenological level, dynamics a dipolar medium, i.e. one endowed with dipole moment vector, polarizable field. Using first-order cosmological perturbations, we show that fluid undistinguishable from (a constant Lambda) plus pressureless perfect fluid), therefore benefits successes Lambda-CDM (Lambda-cold...
In previous work [L. Blanchet and A. Le Tiec, Phys. Rev. D 78, 024031 (2008)], a model of dark matter energy based on the concept gravitational polarization was investigated. This shown to recover concordance cosmological scenario ($\ensuremath{\Lambda}$-cold matter) at scales, phenomenology modified Newtonian dynamics galactic scales. this article we prove that can be formulated with simple physically meaningful action in general relativity. We also provide alternative derivations main...
Using the canonical Arnowitt-Deser-Misner Hamiltonian formalism, a "first law of mechanics" is established for binary systems point masses moving along generic stable bound (eccentric) orbits. This relationship checked to hold within post-Newtonian approximation general relativity, up third (3PN) order. Several applications are discussed, including use gravitational self-force results inform theory and effective one-body model eccentric-orbit compact binaries.
We study the general relativistic periastron advance in spinning black hole binaries on quasi-circular orbits, with spins aligned or anti-aligned orbital angular momentum, using numerical-relativity simulations, post-Newtonian approximation, and perturbation theory. By imposing a symmetry by exchange of bodies' labels, we devise an improved version perturbative result, use it as leading term new type expansion powers symmetric mass ratio. This allows us to measure, for first time,...
We use the canonical Hamiltonian formalism to generalize spinning point particles first law of mechanics established for binary systems nonspinning masses moving on circular orbits [A. Le Tiec, L. Blanchet, and B. F. Whiting, Phys. Rev. D 85, 064039 (2012)]. find that redshift observable each particle is related in a very simple manner and, more generally, class Fokker-type Hamiltonians. Our results are valid through linear order spin particle, but hold also quadratic couplings between spins...
The gravitational self-force (GSF) and post-Newtonian (PN) schemes are complementary approximation methods for modeling the dynamics of compact binary systems. Comparison their results in an overlapping domain validity provides a crucial test both can be used to enhance accuracy, e.g. via determination previously unknown PN parameters. Here, first time, we extend such comparisons noncircular orbits---specifically, system two nonspinning objects bound (eccentric) orbit. To enable comparison...
We present the first fully relativistic study of gravitational radiation from bodies in circular equatorial orbits around massive black hole at Galactic Center, Sgr A* and we assess detectability various kinds objects by wave detector LISA. Our computations are based on theory perturbations Kerr spacetime take into account Roche limit induced tidal forces metric. The signal-to-noise ratio LISA detector, as well time spent band, evaluated. have implemented all computational tools an...
LISA, the Laser Interferometer Space Antenna, will usher in a new era gravitational-wave astronomy. As first anticipated space-based detector, it expand our view to millihertz sky, where spectacular variety of interesting sources abound: from millions ultra-compact binaries Galaxy, mergers massive black holes at cosmological distances; beginnings inspirals that venture into ground-based detectors' death spiral compact objects holes, and many between. Central realising LISA's discovery...
The gravitational recoil or 'kick' of a black hole formed from the merger two orbiting holes, and caused by anisotropic emission radiation, is an astrophysically important phenomenon. We combine (i) earlier calculation, using post-Newtonian theory, kick velocity accumulated up to non-spinning (ii) 'close-limit approximation' calculation radiation emitted during ringdown phase, based on solution Regge–Wheeler Zerilli equations initial data accurate second order. prove that produces...
We derive the first law of binary point-particle mechanics for generic bound (i.e. eccentric) orbits at fourth post-Newtonian (4PN) order, accounting non-locality in time dynamics due to occurence a gravitational-wave tail effect that order. Using this law, we show how periastron advance system can be related averaged redshift one two bodies slightly non-circular orbit, limit where eccentricity vanishes. Combining expression with existing analytical self-force results redshift, recover known...
We formulate a Hamiltonian description of the orbital motion point particle in Kerr spacetime for generic (eccentric, inclined) orbits, which accounts effects conservative part gravitational self-force. This formulation relies on particle's as geodesic certain smooth effective spacetime, terms (generalized) action-angle variables. Clarifying role played by gauge freedom dynamics, we extract gauge-invariant information contained also propose possible choice dynamics can be described an...
We produce gravitational waveforms for nonspinning compact binaries undergoing a quasicircular inspiral. Our approach is based on two-timescale expansion of the Einstein equations in second-order self-force theory, which allows first-principles waveform production tens milliseconds. Although designed extreme mass ratios, our agree remarkably well with those from full numerical relativity, even comparable-mass systems. results will be invaluable accurately modelling extreme-mass-ratio...