REVIEW
Matched filtering of gravitational waves from inspiraling compact binaries: Computational cost and template placement
General Relativity and Quantum Cosmology · Submitted 27 Aug 1998 · 34 references
Pith's verdict: A solid, honest 1998 resource-budget paper: the 2PN template counts and flops figures are the useful contribution, and the soft spots are real but don't move the headline numbers.
T0 · AI review
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Referee report
The paper
The paper claims
A matched-filter search for inspiraling binaries is priced out in templates, flops, and storage, and the bill is large enough to shape how the searches get built.
The reading
What carries the argument
The load-bearing device is a metric on the space of intrinsic binary parameters, built from the match function $M( heta_1, heta_2)$ — the fraction of optimal signal-to-noise recovered by filtering with a template whose parameters differ from the signal's, after maximizing over the unknown coalescence time and phase. Expanding the match about a coincident point gives $M simeq 1 - g_{ij} Delta heta^i Delta heta^j$, so the metric measures how quickly detectability degrades as you move away from the true parameters. The number of templates is then the proper volume of the region of interest divided by the proper volume per lattice cell, with the cell size set by the minimal match and the packing scheme (a rectangle in two dimensions, or a hexagon for a 20% saving). To keep the metric components from varying wildly, the authors use chirp-time coordinates rather than the two masses, and they project out the coalescence time before integrating. A second piece of machinery is the sampling-rate condition: the high-frequency cutoff must be high enough that discretization in time costs less signal-to-noise than discretization in template parameters, which is why their sampling rates, and hence their flop counts, are higher than in earlier work.
Extended reading notes
Core claim
The central claim is a resource budget for a one-step matched-filter search using restricted second post-Newtonian waveforms for nonspinning binaries in circular orbits. Covering all binaries with component masses above $0.2M_*$ while losing no more than 10% of events to coarse template spacing requires about $4.8^{5}$ templates for initial LIGO, $6.9^{6}$ for advanced LIGO, and $9.3^{6}$ for VIRGO on a rectangular lattice at 97% minimal match. Translated through a standard operations count for Fourier-domain filtering, that becomes $9.9^{10}$ flops for initial LIGO, $7.8^{11}$ for advanced LIGO, and $4.8^{12}$ for VIRGO, with stored templates running from $1.5^{11}$ real numbers for TAMA to $6.2^{14}$ for VIRGO. The authors also derive scaling laws: computational power goes roughly as $m_{min}^{-8/3}$ and storage as $m_{min}^{-13/3}$, so pushing the mass threshold down is expensive fast. One pointed corollary they draw is that VIRGO's very broad, flat noise spectrum cannot be fully exploited by this kind of search, because the low-frequency reach multiplies the template count beyond what the available computing can service.
Load-bearing premise
The entire template count rests on treating the match between neighbouring templates as a quadratic bowl out to a 3% mismatch, and the authors' own Fig. 1 caption concedes that at second post-Newtonian order this agreement holds for all but waveforms of massive binaries, which is precisely the corner of parameter space the proper-volume integral includes.
Editorial extensions
If this is right
- Any proposed shortcut — hierarchical two-stage searches, template interpolation, reduced-order waveform generation — now has a concrete number to beat rather than a vague sense that the naive search is costly.
- Detector designers get a warning that a broader or flatter noise spectrum buys sensitivity at a superlinear price in analysis cost, since template count scales as $f_0^{-8/3}$ and power as $f_0^{-5/3}$.
- Searches extending down to subsolar component masses, such as low-mass black hole dark matter candidates, are effectively forced to generate templates on the fly rather than store them, because storage scales as $m_{min}^{-13/3}$.
- The template-placement algorithm, which walks along the equal-mass curve and stacks rows outward in locally diagonalized coordinates, gives an implementable recipe rather than only a count, including the expected boundary spill-over.
- The 97% minimal match is tied to a 10% loss of event rate through the cube of the fitting factor, giving a single tunable dial connecting search thoroughness to computational budget.
Reading between the lines
- The budget is a moving target in a useful sense: because power scales as $m_{min}^{-8/3}$, raising the mass floor from $0.2M_*$ to $1M_*$ cuts the requirement by roughly two orders of magnitude, which suggests the mass threshold is the single most consequential design choice in an inspiral search and deserves explicit justification rather than convention.
- The same geometric machinery should transfer almost unchanged to any waveform family with a smooth parameter dependence, so the metric-plus-proper-volume method is plausibly reusable for eccentricity, spin-aligned, or precessing searches once those waveforms are cheap enough to evaluate.
- The paper's own numbers imply that the decisive engineering question for a real pipeline is not the flop count but the ratio of data-segment length to filter length, since the operations count carries a $log_2 F$ term that the paper fixes rather than optimizes.
- If a hierarchical search really delivers the factor-of-25 reduction attributed to it in the literature, then the naive budget in this paper is comfortably affordable at initial-LIGO sensitivity, which reframes the numbers here as an upper bound on what the problem costs rather than a barrier.
Original abstract
We estimate the number of templates, computational power, and storage required for a one-step matched filtering search for gravitational waves from inspiraling compact binaries. These estimates should serve as benchmarks for the evaluation of more sophisticated strategies such as hierarchical searches. We use waveform templates based on the second post-Newtonian approximation for binaries composed of nonspinning compact bodies in circular orbits. We present estimates for six noise curves: LIGO (three configurations), VIRGO, GEO600, and TAMA. To search for binaries with components more massive than 0.2M_o while losing no more than 10% of events due to coarseness of template spacing, initial LIGO will require about 1*10^11 flops (floating point operations per second) for data analysis to keep up with data acquisition. This is several times higher than estimated in previous work by Owen, in part because of the improved family of templates and in part because we use more realistic (higher) sampling rates. Enhanced LIGO, GEO600, and TAMA will require computational power similar to initial LIGO. Advanced LIGO will require 8*10^11 flops, and VIRGO will require 5*10^12 flops. If the templates are stored rather than generated as needed, storage requirements range from 1.5*10^11 real numbers for TAMA to 6*10^14 for VIRGO. We also sketch and discuss an algorithm for placing the templates in the parameter space.
The compiled record
The paper's own sentences, arranged, kept beside the review and separate from it. Each label is drawn from a closed vocabulary; the number beside it is the probability the classifier gave that label. Numbers in the tables are the authors', checked by code. No sentence in this record was written by a model.
The abstract, sentence by sentence
We estimate the number of templates, computational power, and storage required for a one-step matched filtering search for gravitational waves from inspiraling compact binaries. These estimates should serve as benchmarks for the evaluation of more sophisticated strategies such as hierarchical searches. We use waveform templates based on the second post-Newtonian approximation for binaries composed of nonspinning compact bodies in circular orbits. We present estimates for six noise curves: LIGO (three configurations), VIRGO, GEO600, and TAMA. To search for binaries with components more massive than 0.2M_o while losing no more than 10% of events due to coarseness of template spacing, initial LIGO will require about 1*10^11 flops (floating point operations per second) for data analysis to keep up with data acquisition. This is several times higher than estimated in previous work by Owen, in part because of the improved family of templates and in part because we use more realistic (higher) sampling rates. Enhanced LIGO, GEO600, and TAMA will require computational power similar to initial LIGO. Advanced LIGO will require 8*10^11 flops, and VIRGO will require 5*10^12 flops. If the templates are stored rather than generated as needed, storage requirements range from 1.5*10^11 real numbers for TAMA to 6*10^14 for VIRGO. We also sketch and discuss an algorithm for placing the templates in the parameter space.
background contribution method result interpretation main claim
| # | sentence | role | the authors' own work | states the main conclusion | strength |
|---|---|---|---|---|---|
| s0 | We estimate the number of templates, computational power, and storage required for a one-step matched filtering search for gravitational waves from inspiraling compact binaries. | contribution 1.00 | 0.92 | 0.08 | asserted 0.97 |
| s1 | These estimates should serve as benchmarks for the evaluation of more sophisticated strategies such as hierarchical searches. | interpretation 0.54 | 0.17 | 0.08 | asserted 0.49 |
| s2 | We use waveform templates based on the second post-Newtonian approximation for binaries composed of nonspinning compact bodies in circular orbits. | method 1.00 | 0.71 | 0.03 | asserted 1.00 |
| s3 | We present estimates for six noise curves: LIGO (three configurations), VIRGO, GEO600, and TAMA. | contribution 0.51 | 0.87 | 0.04 | asserted 1.00 |
| s4 | To search for binaries with components more massive than 0.2M_o while losing no more than 10% of events due to coarseness of template spacing, initial LIGO will require about 1*10^11 flops (floating point operations per second) for data analysis to keep up with data acquisition. | result 1.00 | 0.91 | 0.28 | asserted 0.83 |
| s5 | This is several times higher than estimated in previous work by Owen, in part because of the improved family of templates and in part because we use more realistic (higher) sampling rates. | result 0.51 | 0.65 | 0.07 | asserted 0.97 |
| s6 | Enhanced LIGO, GEO600, and TAMA will require computational power similar to initial LIGO. | result 1.00 | 0.85 | 0.06 | asserted 1.00 |
| s7 | Advanced LIGO will require 8*10^11 flops, and VIRGO will require 5*10^12 flops. | result 1.00 | 0.90 | 0.18 | asserted 1.00 |
| s8 | If the templates are stored rather than generated as needed, storage requirements range from 1.5*10^11 real numbers for TAMA to 6*10^14 for VIRGO. | result 1.00 | 0.90 | 0.07 | asserted 0.88 |
| s9 | We also sketch and discuss an algorithm for placing the templates in the parameter space. | contribution 0.57 | 0.89 | 0.03 | asserted 0.89 |
What was examined, and what was not
- arXiv listing abstract v1
- full text
- figures and tables
- references and citing sentences
- relations to other papers
- P abstract
- S sections
- T body sentences
- C citations
- R cross-paper relations
Figures
Figures reproduced from arXiv:gr-qc/9808076 by the authors.
References
How later papers used it
116 later papers cite it
1 later paper by other authors is listed below: 1 used its method or tool. 1 more paper by the same authors is listed: 1 built on it.
Builds on it 1 of 2 papers with this label · 1 by the same authors
By the same authors
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Extended this paper's non-spinning inspiral metric to 3.5 PN order in phase.
Parameter space metric for 3.5 post-Newtonian gravitational-waves from compact binary inspirals (2013) (same authors) · 1.00 · paraphrased: the licence does not allow quoting
Uses its method or tool 1 of 25 papers with this label
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Computed the metric by evaluating the Fisher information matrix of this paper over the full parameter space.
Effectual gravitational-wave template banks for coalescing compact binaries using a hybrid placement algorithm (2017) · 0.99 · paraphrased: the licence does not allow quoting
How the literature uses it
80 arXiv papers cite this in 127 sentences
Papers citing it · 66 sentences without a confident label
Builds on it 2 papers
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We present and employ a geometric method to construct a bank of eccentric waveforms for matched-filtering spanning the intrinsic parameter space $(m^_1, m^_2, s^_1z, s^_2z, e^_0)$, building on the works of [ref] .
A geometric template bank for the detection of spinning low-mass compact binaries with moderate orbital eccentricity · Geometric Approach · 0.89
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Hence in this work we extend the non-spinning inspiral metric of [ref] and [ref] to 3.5 PN order in phase.
Parameter space metric for 3.5 post-Newtonian gravitational-waves from compact binary inspirals · Introduction · 1.00
Uses its method or tool 19 papers
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We used the TaylorF2 second-order post-Newtonian hexagonal placement algorithm of Refs. [ref] to construct a template bank of EOBNRv2 waveforms with $$ of $0.97$.
Template banks to search for low-mass binary black holes in advanced gravitational-wave detectors · Conclusions · 1.00
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For details of template bank construction, we use Ref. [ref] .
Detectability of Sub-Solar Mass Neutron Stars Through a Template Bank Search · Impact on Search Sensitivity · 0.99
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We first generate a template bank for binaries with zero eccentricity and component spin using the standard hexagonal lattice method of template placement [ref] .
Eccentric Binary Neutron Star Search Prospects for Cosmic Explorer · Binary Neutron Star Searches in Cosmic Explorer · 1.00
Compares with it 1 paper
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The size of these banks is comparable to one constructed using the second-order post-Newtonian TaylorF2 hexagonal template placement method [ref] , which yields a grid of $522$ and $736$ templates, for a minimal match of $97%$ and $98%$, respectively.
Template Banks for Binary black hole searches with Numerical Relativity waveforms · Constructing a template bank for NR-PN hybrids · 0.98
Cites it as support 1 paper
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* Mass lower bound — The lower bound of our mass region is informed by the fact that the number of templates required to achieve a predetermined template bank efficiency grows significantly as we approach the low-mass regime (roughly as $N_templates∝ℳ_min^-8/3$ [ref] ).
In Pursuit of Love: First Templated Search for Compact Objects with Large Tidal Deformabilities in the LIGO-Virgo Data · Search Parameter Space · 0.97
Cites it as background 29 papers
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The two-dimensional metric for the inspiral portion of the signal associated with GW from BNS was originally computed at 1.0 PN order [ref] and then extended to 2.0 PN [ref] .
Parameter space metric for 3.5 post-Newtonian gravitational-waves from compact binary inspirals · Introduction · 0.93
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The mismatch can be approximated using a second-order Taylor expansion, allowing to define an analytic metric on the waveform manifold [ref] , which in turn is used to define a regular lattice for placing templates in a locally flat space [ref] .
A geometric template bank for the detection of spinning low-mass compact binaries with moderate orbital eccentricity · Matched Filtering · 0.85
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Gravitational-wave detection searches for BBHs operate by matched-filtering the detector data against a bank of modeled waveform templates [ref] .
Template Banks for Binary black hole searches with Numerical Relativity waveforms · Conclusions · 0.97
Discussion
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