The Fourteenth Marcel Grossmann Meeting, Nov 16, 2017
We address the hyperboloidal initial value problem in the context of Numerical Relativity, motiva... more We address the hyperboloidal initial value problem in the context of Numerical Relativity, motivated by its evolution on hyperboloidal slices: smooth spacelike slices that reach future null infinity, the "location" in spacetime where radiation is to be extracted. Our approach uses the BSSN and Z4 formulations and a time-independent conformal factor. The resulting system of PDEs includes formally diverging terms at null infinity. Here we discuss a regularized numerical scheme in spherical symmetry. A critical ingredient are the gauge conditions, which control the treatment of future null infinity. Stable numerical evolutions have been performed with regular and black hole initial data on a hyperboloidal slice. A sufficiently large scalar field perturbation will create a black hole, whose final stationary state is different from the trumpet initial data derived here.
GW170817 is the very first observation of gravitational waves originating from the coalescence of... more GW170817 is the very first observation of gravitational waves originating from the coalescence of two compact objects in the mass range of neutron stars, accompanied by electromagnetic counterparts, and offers an opportunity to directly probe the internal structure of neutron stars. We perform Bayesian model selection on a wide range of theoretical predictions for the neutron star equation of state. For the binary neutron star hypothesis, we find that we cannot rule out the majority of theoretical models considered. In addition, the gravitational-wave data alone does not rule out the possibility that one or both objects were low-mass black holes. We discuss the possible outcomes in the case of a binary neutron star merger, finding that all scenarios from prompt collapse to long-lived or even stable remnants are possible. For long-lived remnants, we place an upper limit of 1.9 kHz on the rotation rate. If a black hole was formed any time after merger and the coalescing stars were slo...
A useful choice of gauge when including null infinity in the computational domain is scri-fixing,... more A useful choice of gauge when including null infinity in the computational domain is scri-fixing, that is, fixing the spatial coordinate location of null infinity. This choice allows us to avoid the introduction of artificial timelike outer boundaries in numerical calculations. We construct manifestly stationary scri-fixing coordinates explicitly on Minkowski, Schwarzschild and Kerr spacetimes.
Maite Mateu-Lucena,1 Sascha Husa,1 Marta Colleoni,1 Héctor Estellés,1 Cecilio García-Quirós,1 Dav... more Maite Mateu-Lucena,1 Sascha Husa,1 Marta Colleoni,1 Héctor Estellés,1 Cecilio García-Quirós,1 David Keitel,1 Maria de Lluc Planas,1 and Antoni Ramos-Buades2, 1 1Departament de Física, Universitat de les Illes Balears, IAC3 – IEEC, Crta. Valldemossa km 7.5, E-07122 Palma, Spain 2Max Plank Institut für Gravitationsphysik (Albert Einstein Institut), Am Mühlenberg 1, Potsdam, Germany (Dated: June 4, 2021)
We consider the 10 confidently detected gravitational-wave signals in the GWTC-1 catalog, which a... more We consider the 10 confidently detected gravitational-wave signals in the GWTC-1 catalog, which are consistent with mergers of binary black hole systems, and perform a thorough parameter estimation re-analysis. This is made possible by using computationally efficient waveform models of the current (fourth) generation of the IMRPhenom family of phenomenological waveform models, which consists of the IMRPhenomX frequency-domain models and the IMRPhenomT time-domain models.The analysis is performed with both precessing and non-precessing waveform models with and without subdominant spherical harmonic modes. Results for all events are validated with convergence tests, discussing in particular the events GW170729 and GW151226. For the latter and the other two lowest-mass events, we also compare results between two independent sampling codes, bilbyand lalinference. We find overall consistent results with the original GWTC-1 results, with all Jensen–Shannon divergences between the previous...
This document describes the Conceptual Design of a third generation gravitational wave observator... more This document describes the Conceptual Design of a third generation gravitational wave observatory named<br> Einstein Telescope (\ET"). The design of this new research infrastructure has been realised with the support of<br> the European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement n 211743.<br> In this document are described the fundamental design options, the site requirements, the main technological<br> solutions, a rough evaluation of the costs and a schematic time plan.
This paper presents an algorithm to accelerate the evaluation of inspiral–merger–ringdown wavefor... more This paper presents an algorithm to accelerate the evaluation of inspiral–merger–ringdown waveform models for gravitational wave data analysis. While the idea can also be applied in the time domain, here we focus on the frequency domain, which is most typically used to reduce computational cost in gravitational wave data analysis. Our work extends the idea of multibanding Vinciguerra S et al (2017 Class. Quantum Grav. 34 115006), which has been developed to accelerate frequency domain waveforms, to include the merger and ringdown and spherical harmonics beyond the dominant quadrupole spherical harmonic. The original method of Vinciguerra S et al (2017 Class. Quantum Grav. 34 115006) is based on a heuristic algorithm based on the inspiral to de-refine the equi-spaced frequency grid used for data analysis where a coarser grid is sufficient for accurate evaluation of a waveform model. Here we use a different criterion, based on the local interpolation error, which is more flexible and ...
The current paradigm for constructing waveforms from precessing compact binaries is to first cons... more The current paradigm for constructing waveforms from precessing compact binaries is to first construct a waveform in a non-inertial, co-precessing binary source frame followed by a time-dependent rotation to map back to the physical, inertial frame. A key insight in the construction of these models is that the co-precessing waveform can be effectively mapped to some equivalent aligned spin waveform. Secondly, the time-dependent rotation implicitly introduces m-mode mixing, necessitating an accurate description of higher-order modes in the co-precessing frame. We assess the efficacy of this modelling strategy in the strong field regime using Numerical Relativity simulations. We find that this framework allows for the highly accurate construction of (2, ±2) modes in our data set, while for higher order modes, especially the (2, |1|), (3, |2|) and (4, |3|) modes, we find rather large mismatches. We also investigate a variant of the approximate map between co-precessing and aligned spin waveforms, where we only identify the slowly varying part of the time domain co-precessing waveforms with the aligned-spin one, but find no significant improvement. Our results indicate that the simple paradigm to construct precessing waveforms does not provide an accurate description of higher order modes in the strong-field regime, and demonstrate the necessity for modelling mode asymmetries and mode-mixing to significantly improve the description of precessing higher order modes.
In this paper we present IMRP XAS, a thorough overhaul of the IMRP D [1, 2] waveform model, which... more In this paper we present IMRP XAS, a thorough overhaul of the IMRP D [1, 2] waveform model, which describes the dominant l = 2, |m| = 2 spherical harmonic mode of non-precessing coalescing black holes in terms of piecewise closed form expressions in the frequency domain. Improvements include in particular the accurate treatment of unequal spin effects, and the inclusion of extreme mass ratio waveforms. IMRP D has previously been extended to approximately include spin precession [3] and subdominant spherical harmonics [4], and with its extensions it has become a standard tool in gravitational wave parameter estimation. Improved extensions of IMRP XAS are discussed in companion papers [5, 6].
We present TEOBResumS, a new effective-one-body (EOB) waveform model for nonprecessing (spinalign... more We present TEOBResumS, a new effective-one-body (EOB) waveform model for nonprecessing (spinaligned) and tidally interacting compact binaries. Spin-orbit and spin-spin effects are blended together by making use of the concept of centrifugal EOB radius. The point-mass sector through merger and ringdown is informed by numerical relativity (NR) simulations of binary black holes (BBH) computed with the SpEC and BAM codes. An improved, NR-based phenomenological description of the postmerger waveform is developed. The tidal sector of TEOBResumS describes the dynamics of neutron star binaries up to merger and incorporates a resummed attractive potential motivated by recent advances in the post-Newtonian and gravitational self-force description of relativistic tidal interactions. Equation-of-state dependent self-spin interactions (monopole-quadrupole effects) are incorporated in the model using leading-order post-Newtonian results in a new expression of the centrifugal radius. TEOBResumS is compared to 135 SpEC and 19 BAM BBH waveforms. The maximum unfaithfulness to SpEC dataF-at design Advanced-LIGO sensitivity and evaluated with total mass M varying between 10M ≤ M ≤ 200M-is always below 2.5 × 10 −3 except for a single outlier that grazes the 7.1 × 10 −3 level. When compared to BAM data,F is smaller than 0.01 except for a single outlier in one of the corners of the NR-covered parameter space, that reaches the 0.052 level. TEOBResumS is also compatible, up to merger, to high end NR waveforms from binary neutron stars with spin effects and reduced initial eccentricity computed with the BAM and THC codes. The data quality of binary neutron star waveforms is assessed via rigorous convergence tests from multiple resolution runs and takes into account systematic effects estimated by using the two independent high-order NR codes. The model is designed to generate accurate templates for the analysis of LIGO-Virgo data through merger and ringdown. We demonstrate its use by analyzing the publicly available data for GW150914.
Gravitational-wave observations of binary black holes currently rely on theoretical models that p... more Gravitational-wave observations of binary black holes currently rely on theoretical models that predict the dominant multipoles (ℓ=2,|m|=2) of the radiation during inspiral, merger, and ringdown. We introduce a simple method to include the subdominant multipoles to binary black hole gravitational waveforms, given a frequency-domain model for the dominant multipoles. The amplitude and phase of the original model are appropriately stretched and rescaled using post-Newtonian results (for the inspiral), perturbation theory (for the ringdown), and a smooth transition between the two. No additional tuning to numerical-relativity simulations is required. We apply a variant of this method to the nonprecessing PhenomD model. The result, PhenomHM, constitutes the first higher-multipole model of spinning and coalescing black-hole binaries, and currently includes the (ℓ,|m|)=(2,2),(3,3),(4,4),(2,1),(3,2),(4,3) radiative moments. Comparisons with numerical-relativity waveforms demonstrate that P...
Numerical relativity is an essential tool in studying the coalescence of binary black holes (BBHs... more Numerical relativity is an essential tool in studying the coalescence of binary black holes (BBHs). It is still computationally prohibitive to cover the BBH parameter space exhaustively, making phenomenological fitting formulas for BBH waveforms and final-state properties important for practical applications. We describe a general hierarchical bottom-up fitting methodology to design and calibrate fits to numerical relativity simulations for the three-dimensional parameter space of quasicircular nonprecessing merging BBHs, spanned by mass ratio and by the individual spin components orthogonal to the orbital plane. Particular attention is paid to incorporating the extreme-mass-ratio limit and to the subdominant unequal-spin effects. As an illustration of the method, we provide two applications, to the final spin and final mass (or equivalently: radiated energy) of the remnant black hole. Fitting to 427 numerical relativity simulations, we obtain results broadly consistent with previously published fits, but improving in overall accuracy and particularly in the approach to extremal limits and for unequal-spin configurations. We also discuss the importance of data quality studies when combining simulations from diverse sources, how detailed error budgets will be necessary for further improvements of these already highly accurate fits, and how this first detailed study of unequal-spin effects helps in choosing the most informative parameters for future numerical relativity runs.
We present a new frequency-domain phenomenological model of the gravitational-wave signal from th... more We present a new frequency-domain phenomenological model of the gravitational-wave signal from the inspiral, merger and ringdown of nonprecessing (aligned-spin) black-hole binaries. The model is calibrated to 19 hybrid effective-one-body-numerical-relativity waveforms up to mass ratios of 1∶18 and black-hole spins of ja=mj ∼ 0.85 (0.98 for equal-mass systems). The inspiral part of the model consists of an extension of frequency-domain post-Newtonian expressions, using higher-order terms fit to the hybrids. The merger ringdown is based on a phenomenological ansatz that has been significantly improved over previous models. The model exhibits mismatches of typically less than 1% against all 19 calibration hybrids and an additional 29 verification hybrids, which provide strong evidence that, over the calibration region, the model is sufficiently accurate for all relevant gravitational-wave astronomy applications with the Advanced LIGO and Virgo detectors. Beyond the calibration region the model produces physically reasonable results, although we recommend caution in assuming that any merger-ringdown waveform model is accurate outside its calibration region. As an example, we note that an alternative nonprecessing model, SEOBNRv2 (calibrated up to spins of only 0.5 for unequal-mass systems), exhibits mismatch errors of up to 10% for high spins outside its calibration region. We conclude that waveform models would benefit most from a larger number of numerical-relativity simulations of high-aligned-spin unequal-mass binaries.
High Performance Computing in Science and Engineering, Garching/Munich 2007
We summarize numerical simulations of black hole binaries performed on the HLRB II (SGI Altix 470... more We summarize numerical simulations of black hole binaries performed on the HLRB II (SGI Altix 4700) in the time frame 2006-2007. The numerical methods as well as their performance are presented in detail. We summarize modifications of the numerical methods and their impact on accuracy and efficiency of our simulations. We also report on the physical results extracted from these simulations. These concern black-hole physics in general as well as the use of our numerically generated waveforms in the ongoing effort to detect gravitational waves.
The Fourteenth Marcel Grossmann Meeting, Nov 16, 2017
We address the hyperboloidal initial value problem in the context of Numerical Relativity, motiva... more We address the hyperboloidal initial value problem in the context of Numerical Relativity, motivated by its evolution on hyperboloidal slices: smooth spacelike slices that reach future null infinity, the "location" in spacetime where radiation is to be extracted. Our approach uses the BSSN and Z4 formulations and a time-independent conformal factor. The resulting system of PDEs includes formally diverging terms at null infinity. Here we discuss a regularized numerical scheme in spherical symmetry. A critical ingredient are the gauge conditions, which control the treatment of future null infinity. Stable numerical evolutions have been performed with regular and black hole initial data on a hyperboloidal slice. A sufficiently large scalar field perturbation will create a black hole, whose final stationary state is different from the trumpet initial data derived here.
GW170817 is the very first observation of gravitational waves originating from the coalescence of... more GW170817 is the very first observation of gravitational waves originating from the coalescence of two compact objects in the mass range of neutron stars, accompanied by electromagnetic counterparts, and offers an opportunity to directly probe the internal structure of neutron stars. We perform Bayesian model selection on a wide range of theoretical predictions for the neutron star equation of state. For the binary neutron star hypothesis, we find that we cannot rule out the majority of theoretical models considered. In addition, the gravitational-wave data alone does not rule out the possibility that one or both objects were low-mass black holes. We discuss the possible outcomes in the case of a binary neutron star merger, finding that all scenarios from prompt collapse to long-lived or even stable remnants are possible. For long-lived remnants, we place an upper limit of 1.9 kHz on the rotation rate. If a black hole was formed any time after merger and the coalescing stars were slo...
A useful choice of gauge when including null infinity in the computational domain is scri-fixing,... more A useful choice of gauge when including null infinity in the computational domain is scri-fixing, that is, fixing the spatial coordinate location of null infinity. This choice allows us to avoid the introduction of artificial timelike outer boundaries in numerical calculations. We construct manifestly stationary scri-fixing coordinates explicitly on Minkowski, Schwarzschild and Kerr spacetimes.
Maite Mateu-Lucena,1 Sascha Husa,1 Marta Colleoni,1 Héctor Estellés,1 Cecilio García-Quirós,1 Dav... more Maite Mateu-Lucena,1 Sascha Husa,1 Marta Colleoni,1 Héctor Estellés,1 Cecilio García-Quirós,1 David Keitel,1 Maria de Lluc Planas,1 and Antoni Ramos-Buades2, 1 1Departament de Física, Universitat de les Illes Balears, IAC3 – IEEC, Crta. Valldemossa km 7.5, E-07122 Palma, Spain 2Max Plank Institut für Gravitationsphysik (Albert Einstein Institut), Am Mühlenberg 1, Potsdam, Germany (Dated: June 4, 2021)
We consider the 10 confidently detected gravitational-wave signals in the GWTC-1 catalog, which a... more We consider the 10 confidently detected gravitational-wave signals in the GWTC-1 catalog, which are consistent with mergers of binary black hole systems, and perform a thorough parameter estimation re-analysis. This is made possible by using computationally efficient waveform models of the current (fourth) generation of the IMRPhenom family of phenomenological waveform models, which consists of the IMRPhenomX frequency-domain models and the IMRPhenomT time-domain models.The analysis is performed with both precessing and non-precessing waveform models with and without subdominant spherical harmonic modes. Results for all events are validated with convergence tests, discussing in particular the events GW170729 and GW151226. For the latter and the other two lowest-mass events, we also compare results between two independent sampling codes, bilbyand lalinference. We find overall consistent results with the original GWTC-1 results, with all Jensen–Shannon divergences between the previous...
This document describes the Conceptual Design of a third generation gravitational wave observator... more This document describes the Conceptual Design of a third generation gravitational wave observatory named<br> Einstein Telescope (\ET"). The design of this new research infrastructure has been realised with the support of<br> the European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement n 211743.<br> In this document are described the fundamental design options, the site requirements, the main technological<br> solutions, a rough evaluation of the costs and a schematic time plan.
This paper presents an algorithm to accelerate the evaluation of inspiral–merger–ringdown wavefor... more This paper presents an algorithm to accelerate the evaluation of inspiral–merger–ringdown waveform models for gravitational wave data analysis. While the idea can also be applied in the time domain, here we focus on the frequency domain, which is most typically used to reduce computational cost in gravitational wave data analysis. Our work extends the idea of multibanding Vinciguerra S et al (2017 Class. Quantum Grav. 34 115006), which has been developed to accelerate frequency domain waveforms, to include the merger and ringdown and spherical harmonics beyond the dominant quadrupole spherical harmonic. The original method of Vinciguerra S et al (2017 Class. Quantum Grav. 34 115006) is based on a heuristic algorithm based on the inspiral to de-refine the equi-spaced frequency grid used for data analysis where a coarser grid is sufficient for accurate evaluation of a waveform model. Here we use a different criterion, based on the local interpolation error, which is more flexible and ...
The current paradigm for constructing waveforms from precessing compact binaries is to first cons... more The current paradigm for constructing waveforms from precessing compact binaries is to first construct a waveform in a non-inertial, co-precessing binary source frame followed by a time-dependent rotation to map back to the physical, inertial frame. A key insight in the construction of these models is that the co-precessing waveform can be effectively mapped to some equivalent aligned spin waveform. Secondly, the time-dependent rotation implicitly introduces m-mode mixing, necessitating an accurate description of higher-order modes in the co-precessing frame. We assess the efficacy of this modelling strategy in the strong field regime using Numerical Relativity simulations. We find that this framework allows for the highly accurate construction of (2, ±2) modes in our data set, while for higher order modes, especially the (2, |1|), (3, |2|) and (4, |3|) modes, we find rather large mismatches. We also investigate a variant of the approximate map between co-precessing and aligned spin waveforms, where we only identify the slowly varying part of the time domain co-precessing waveforms with the aligned-spin one, but find no significant improvement. Our results indicate that the simple paradigm to construct precessing waveforms does not provide an accurate description of higher order modes in the strong-field regime, and demonstrate the necessity for modelling mode asymmetries and mode-mixing to significantly improve the description of precessing higher order modes.
In this paper we present IMRP XAS, a thorough overhaul of the IMRP D [1, 2] waveform model, which... more In this paper we present IMRP XAS, a thorough overhaul of the IMRP D [1, 2] waveform model, which describes the dominant l = 2, |m| = 2 spherical harmonic mode of non-precessing coalescing black holes in terms of piecewise closed form expressions in the frequency domain. Improvements include in particular the accurate treatment of unequal spin effects, and the inclusion of extreme mass ratio waveforms. IMRP D has previously been extended to approximately include spin precession [3] and subdominant spherical harmonics [4], and with its extensions it has become a standard tool in gravitational wave parameter estimation. Improved extensions of IMRP XAS are discussed in companion papers [5, 6].
We present TEOBResumS, a new effective-one-body (EOB) waveform model for nonprecessing (spinalign... more We present TEOBResumS, a new effective-one-body (EOB) waveform model for nonprecessing (spinaligned) and tidally interacting compact binaries. Spin-orbit and spin-spin effects are blended together by making use of the concept of centrifugal EOB radius. The point-mass sector through merger and ringdown is informed by numerical relativity (NR) simulations of binary black holes (BBH) computed with the SpEC and BAM codes. An improved, NR-based phenomenological description of the postmerger waveform is developed. The tidal sector of TEOBResumS describes the dynamics of neutron star binaries up to merger and incorporates a resummed attractive potential motivated by recent advances in the post-Newtonian and gravitational self-force description of relativistic tidal interactions. Equation-of-state dependent self-spin interactions (monopole-quadrupole effects) are incorporated in the model using leading-order post-Newtonian results in a new expression of the centrifugal radius. TEOBResumS is compared to 135 SpEC and 19 BAM BBH waveforms. The maximum unfaithfulness to SpEC dataF-at design Advanced-LIGO sensitivity and evaluated with total mass M varying between 10M ≤ M ≤ 200M-is always below 2.5 × 10 −3 except for a single outlier that grazes the 7.1 × 10 −3 level. When compared to BAM data,F is smaller than 0.01 except for a single outlier in one of the corners of the NR-covered parameter space, that reaches the 0.052 level. TEOBResumS is also compatible, up to merger, to high end NR waveforms from binary neutron stars with spin effects and reduced initial eccentricity computed with the BAM and THC codes. The data quality of binary neutron star waveforms is assessed via rigorous convergence tests from multiple resolution runs and takes into account systematic effects estimated by using the two independent high-order NR codes. The model is designed to generate accurate templates for the analysis of LIGO-Virgo data through merger and ringdown. We demonstrate its use by analyzing the publicly available data for GW150914.
Gravitational-wave observations of binary black holes currently rely on theoretical models that p... more Gravitational-wave observations of binary black holes currently rely on theoretical models that predict the dominant multipoles (ℓ=2,|m|=2) of the radiation during inspiral, merger, and ringdown. We introduce a simple method to include the subdominant multipoles to binary black hole gravitational waveforms, given a frequency-domain model for the dominant multipoles. The amplitude and phase of the original model are appropriately stretched and rescaled using post-Newtonian results (for the inspiral), perturbation theory (for the ringdown), and a smooth transition between the two. No additional tuning to numerical-relativity simulations is required. We apply a variant of this method to the nonprecessing PhenomD model. The result, PhenomHM, constitutes the first higher-multipole model of spinning and coalescing black-hole binaries, and currently includes the (ℓ,|m|)=(2,2),(3,3),(4,4),(2,1),(3,2),(4,3) radiative moments. Comparisons with numerical-relativity waveforms demonstrate that P...
Numerical relativity is an essential tool in studying the coalescence of binary black holes (BBHs... more Numerical relativity is an essential tool in studying the coalescence of binary black holes (BBHs). It is still computationally prohibitive to cover the BBH parameter space exhaustively, making phenomenological fitting formulas for BBH waveforms and final-state properties important for practical applications. We describe a general hierarchical bottom-up fitting methodology to design and calibrate fits to numerical relativity simulations for the three-dimensional parameter space of quasicircular nonprecessing merging BBHs, spanned by mass ratio and by the individual spin components orthogonal to the orbital plane. Particular attention is paid to incorporating the extreme-mass-ratio limit and to the subdominant unequal-spin effects. As an illustration of the method, we provide two applications, to the final spin and final mass (or equivalently: radiated energy) of the remnant black hole. Fitting to 427 numerical relativity simulations, we obtain results broadly consistent with previously published fits, but improving in overall accuracy and particularly in the approach to extremal limits and for unequal-spin configurations. We also discuss the importance of data quality studies when combining simulations from diverse sources, how detailed error budgets will be necessary for further improvements of these already highly accurate fits, and how this first detailed study of unequal-spin effects helps in choosing the most informative parameters for future numerical relativity runs.
We present a new frequency-domain phenomenological model of the gravitational-wave signal from th... more We present a new frequency-domain phenomenological model of the gravitational-wave signal from the inspiral, merger and ringdown of nonprecessing (aligned-spin) black-hole binaries. The model is calibrated to 19 hybrid effective-one-body-numerical-relativity waveforms up to mass ratios of 1∶18 and black-hole spins of ja=mj ∼ 0.85 (0.98 for equal-mass systems). The inspiral part of the model consists of an extension of frequency-domain post-Newtonian expressions, using higher-order terms fit to the hybrids. The merger ringdown is based on a phenomenological ansatz that has been significantly improved over previous models. The model exhibits mismatches of typically less than 1% against all 19 calibration hybrids and an additional 29 verification hybrids, which provide strong evidence that, over the calibration region, the model is sufficiently accurate for all relevant gravitational-wave astronomy applications with the Advanced LIGO and Virgo detectors. Beyond the calibration region the model produces physically reasonable results, although we recommend caution in assuming that any merger-ringdown waveform model is accurate outside its calibration region. As an example, we note that an alternative nonprecessing model, SEOBNRv2 (calibrated up to spins of only 0.5 for unequal-mass systems), exhibits mismatch errors of up to 10% for high spins outside its calibration region. We conclude that waveform models would benefit most from a larger number of numerical-relativity simulations of high-aligned-spin unequal-mass binaries.
High Performance Computing in Science and Engineering, Garching/Munich 2007
We summarize numerical simulations of black hole binaries performed on the HLRB II (SGI Altix 470... more We summarize numerical simulations of black hole binaries performed on the HLRB II (SGI Altix 4700) in the time frame 2006-2007. The numerical methods as well as their performance are presented in detail. We summarize modifications of the numerical methods and their impact on accuracy and efficiency of our simulations. We also report on the physical results extracted from these simulations. These concern black-hole physics in general as well as the use of our numerically generated waveforms in the ongoing effort to detect gravitational waves.
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