14 research outputs found
Analytical and numerical treatment of perturbed black holes in horizon-penetrating coordinates
The deviations of non-linear perturbations of black holes from the linear
case are important in the context of ringdown signals with large
signal-to-noise ratio. To facilitate a comparison between the two we derive
several results of linear perturbation theory in coordinates which may be
adopted in numerical work. Specifically, our results are derived in Kerr-Schild
coordinates adjusted by a general height function. In the first part of the
paper we address the questions: for an initial configuration of a massless
scalar field, what is the amplitude of the excited quasinormal mode (QNM) for
any observer outside outside the event horizon, and furthermore what is the
resulting tail contribution? This is done by constructing the full Green's
function for the problem with exact solutions of the confluent Heun equation
satisfying appropriate boundary conditions. In the second part of the paper, we
detail new developments to our pseudospectral numerical relativity code bamps
to handle scalar fields. In the linear regime we employ precisely the
Kerr-Schild coordinates treated by our previous analysis. In particular, we
evolve pure QNM type initial data along with several other types of initial
data and report on the presence of overtone modes in the signal.Comment: 25 pages, 7 figure
Eccentric binary black holes: Comparing numerical relativity and small mass-ratio perturbation theory
The modelling of unequal mass binary black hole systems is of high importance
to detect and estimate parameters from these systems. Numerical relativity (NR)
is well suited to study systems with comparable component masses, , whereas small mass ratio (SMR) perturbation theory applies to binaries
where . This work investigates the applicability for NR and SMR
as a function of mass ratio for eccentric non-spinning binary black holes. We
produce NR simulations with mass ratios between and and
initial eccentricities up to . From these we extract quantities like
gravitational wave energy and angular momentum fluxes and periastron advance,
and assess their accuracy. To facilitate comparison, we develop tools to map
between NR and SMR inspiral evolutions of eccentric binary black holes. We
derive post-Newtonian accurate relations between different definitions of
eccentricity. Based on these analyses, we introduce a new definition of
eccentricity based on the (2,2)-mode of the gravitational radiation, which
reduces to the Newtonian definition of eccentricity in the Newtonian limit.
From the comparison between NR simulations and SMR results, we quantify the
unknown next-to-leading order SMR contributions to the gravitational energy and
angular momentum fluxes, and periastron advance. We show that in the comparable
mass regime these contributions are subdominant and higher order SMR
contributions are negligible
Worldtube excision method for intermediate-mass-ratio inspirals: scalar-field model in 3+1 dimensions
Binary black hole simulations become increasingly more computationally
expensive with smaller mass ratios, partly because of the longer evolution
time, and partly because the lengthscale disparity dictates smaller time steps.
The program initiated by Dhesi et al. (arXiv:2109.03531) explores a method for
alleviating the scale disparity in simulations with mass ratios in the
intermediate astrophysical range (), where
purely perturbative methods may not be adequate. A region ("worldtube") much
larger than the small black hole is excised from the numerical domain, and
replaced with an analytical model approximating a tidally deformed black hole.
Here we apply this idea to a toy model of a scalar charge in a fixed circular
geodesic orbit around a Schwarzschild black hole, solving for the massless
Klein-Gordon field. This is a first implementation of the worldtube excision
method in full 3+1 dimensions. We demonstrate the accuracy and efficiency of
the method, and discuss the steps towards applying it for evolving orbits and,
ultimately, in the binary black-hole scenario. Our implementation is publicly
accessible in the SpECTRE numerical relativity code.Comment: 19 pages, 10 figure
The SXS Collaboration catalog of binary black hole simulations
Accurate models of gravitational waves from merging black holes are necessary
for detectors to observe as many events as possible while extracting the
maximum science. Near the time of merger, the gravitational waves from merging
black holes can be computed only using numerical relativity. In this paper, we
present a major update of the Simulating eXtreme Spacetimes (SXS) Collaboration
catalog of numerical simulations for merging black holes. The catalog contains
2018 distinct configurations (a factor of 11 increase compared to the 2013 SXS
catalog), including 1426 spin-precessing configurations, with mass ratios
between 1 and 10, and spin magnitudes up to 0.998. The median length of a
waveform in the catalog is 39 cycles of the dominant
gravitational-wave mode, with the shortest waveform containing 7.0 cycles and
the longest 351.3 cycles. We discuss improvements such as correcting for moving
centers of mass and extended coverage of the parameter space. We also present a
thorough analysis of numerical errors, finding typical truncation errors
corresponding to a waveform mismatch of . The simulations provide
remnant masses and spins with uncertainties of 0.03% and 0.1% (
percentile), about an order of magnitude better than analytical models for
remnant properties. The full catalog is publicly available at
https://www.black-holes.org/waveforms .Comment: 33+18 pages, 13 figures, 4 tables, 2,018 binaries. Catalog metadata
in ancillary JSON file. v2: Matches version accepted by CQG. Catalog
available at https://www.black-holes.org/waveform
Laying the foundation of the effective-one-body waveform models SEOBNRv5: improved accuracy and efficiency for spinning non-precessing binary black holes
We present SEOBNRv5HM, a more accurate and faster inspiral-merger-ringdown
gravitational waveform model for quasi-circular, spinning, nonprecessing binary
black holes within the effective-one-body (EOB) formalism. Compared to its
predecessor, SEOBNRv4HM, the waveform model i) incorporates recent high-order
post- Newtonian results in the inspiral, with improved resummations, ii)
includes the gravitational modes (l, |m|) = (3, 2), (4, 3), in addition to the
(2, 2), (3, 3), (2, 1), (4, 4), (5, 5) modes already implemented in SEOBNRv4HM,
iii) is calibrated to larger mass-ratios and spins using a catalog of 442
numerical-relativity (NR) simulations and 13 additional waveforms from
black-hole perturbation theory, iv) incorporates information from second-order
gravitational self-force (2GSF) in the nonspinning modes and radiation-reaction
force. Computing the unfaithfulness against NR simulations, we find that for
the dominant (2, 2) mode the maximum unfaithfulness in the total mass range
is below for 90% of the cases (38% for
SEOBNRv4HM). When including all modes up to l = 5 we find 98% (49%) of the
cases with unfaithfulness below , while these numbers reduce
to 88% (5%) when using SEOBNRv4HM. Furthermore, the model shows improved
agreement with NR in other dynamical quantities (e.g., the angular momentum
flux and binding energy), providing a powerful check of its physical
robustness. We implemented the waveform model in a high-performance Python
package (pySEOBNR), which leads to evaluation times faster than SEOBNRv4HM by a
factor 10 to 50, depending on the configuration, and provides the flexibility
to easily include spin-precession and eccentric effects, thus making it the
starting point for a new generation of EOBNR waveform models (SEOBNRv5) to be
employed for upcoming observing runs of the LIGO-Virgo-KAGRA detectors
The SXS Collaboration catalog of binary black hole simulations
Accurate models of gravitational waves from merging black holes are necessary for detectors to observe as many events as possible while extracting the maximum science. Near the time of merger, the gravitational waves from merging black holes can be computed only using numerical relativity. In this paper, we present a major update of the Simulating eXtreme Spacetimes (SXS) Collaboration catalog of numerical simulations for merging black holes. The catalog contains 2018 distinct configurations (a factor of 11 increase compared to the 2013 SXS catalog), including 1426 spin-precessing configurations, with mass ratios between 1 and 10, and spin magnitudes up to 0.998. The median length of a waveform in the catalog is 39 cycles of the dominant ℓ = m = 2 gravitational-wave mode, with the shortest waveform containing 7.0 cycles and the longest 351.3 cycles. We discuss improvements such as correcting for moving centers of mass and extended coverage of the parameter space. We also present a thorough analysis of numerical errors, finding typical truncation errors corresponding to a waveform mismatch of  ~10−4. The simulations provide remnant masses and spins with uncertainties of 0.03% and 0.1% (90th percentile), about an order of magnitude better than analytical models for remnant properties. The full catalog is publicly available at www.black-holes.org/waveforms
Laying the foundation of the effective-one-body waveform models SEOBNRv5: improved accuracy and efficiency for spinning non-precessing binary black holes
International audienceWe present SEOBNRv5HM, a more accurate and faster inspiral-merger-ringdown gravitational waveform model for quasi-circular, spinning, nonprecessing binary black holes within the effective-one-body (EOB) formalism. Compared to its predecessor, SEOBNRv4HM, the waveform model i) incorporates recent high-order post- Newtonian results in the inspiral, with improved resummations, ii) includes the gravitational modes (l, |m|) = (3, 2), (4, 3), in addition to the (2, 2), (3, 3), (2, 1), (4, 4), (5, 5) modes already implemented in SEOBNRv4HM, iii) is calibrated to larger mass-ratios and spins using a catalog of 442 numerical-relativity (NR) simulations and 13 additional waveforms from black-hole perturbation theory, iv) incorporates information from second-order gravitational self-force (2GSF) in the nonspinning modes and radiation-reaction force. Computing the unfaithfulness against NR simulations, we find that for the dominant (2, 2) mode the maximum unfaithfulness in the total mass range is below for 90% of the cases (38% for SEOBNRv4HM). When including all modes up to l = 5 we find 98% (49%) of the cases with unfaithfulness below , while these numbers reduce to 88% (5%) when using SEOBNRv4HM. Furthermore, the model shows improved agreement with NR in other dynamical quantities (e.g., the angular momentum flux and binding energy), providing a powerful check of its physical robustness. We implemented the waveform model in a high-performance Python package (pySEOBNR), which leads to evaluation times faster than SEOBNRv4HM by a factor 10 to 50, depending on the configuration, and provides the flexibility to easily include spin-precession and eccentric effects, thus making it the starting point for a new generation of EOBNR waveform models (SEOBNRv5) to be employed for upcoming observing runs of the LIGO-Virgo-KAGRA detectors