General Relativistic Models of Binary Neutron Stars in Quasiequilibrium

G. B. Cook; M. A. Scheel; S. A. Teukolsky; S. L. Shapiro; T. W. Baumgarte

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General Relativistic Models of Binary Neutron Stars in Quasiequilibrium

T. W. Baumgarte, G. B. Cook, M. A. Scheel, S. L. Shapiro, S. A. Teukolsky

General Relativity and Quantum Cosmology · Submitted 11 Sep 1997

abstract compiled · 2026-09-23 · no language-model review

The authors' main claim A radial stability analysis reveals no tendency for neutron stars in close binaries to collapse to black holes prior to merger.

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arXiv IDgr-qc/9709026 (version 1)

Pith ID7J7PXOWK, Pith's permanent record of this paper and its review

CitationG. B. Cook, M. A. Scheel, S. A. Teukolsky, S. L. Shapiro, T. W. Baumgarte. "General Relativistic Models of Binary Neutron Stars in Quasiequilibrium." arXiv:gr-qc/9709026 (1997). https://pith.science/paper/7J7PXOWK

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The paper's own sentences, arranged. 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.

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What the abstract itself states, as probabilities: claims first 0.58 · states limitation 0.53 · human participants 0.01 · controlled comparison 0.04 · randomized assignment 0.01 · states quantitative result 0.36 · compares with prior results 0.18 · mentions code or data availability 0.02.

The abstract, sentence by sentence

arXiv listing abstract v1. Results and the main claim are underlined; show every role.

We perform fully relativistic calculations of binary neutron stars in corotating, circular orbit. While Newtonian gravity allows for a strict equilibrium, a relativistic binary system emits gravitational radiation, causing the system to lose energy and slowly spiral inwards. However, since inspiral occurs on a time scale much longer than the orbital period, we can treat the binary to be in quasiequilibrium. In this approximation, we integrate a subset of the Einstein equations coupled to the relativistic equation of hydrostatic equilibrium to solve the initial value problem for binaries of arbitrary separation. We adopt a polytropic equation of state to determine the structure and maximum mass of neutron stars in close binaries for polytropic indices n=1, 1.5 and 2. We construct sequences of constant rest-mass and locate turning points along energy equilibrium curves to identify the onset of orbital instability. In particular, we locate the innermost stable circular orbit (ISCO) and its angular velocity. We construct the first contact binary systems in full general relativity. These arise whenever the equation of state is sufficiently soft >= 1.5. A radial stability analysis reveals no tendency for neutron stars in close binaries to collapse to black holes prior to merger.

background contribution method result interpretation main claim

What the classifier reports for each sentence. The number is the probability it gave the label.
#	sentence	role	the authors' own work	states the main conclusion	strength
s0	We perform fully relativistic calculations of binary neutron stars in corotating, circular orbit.	contribution 0.85	0.97	0.04	asserted 1.00
s1	While Newtonian gravity allows for a strict equilibrium, a relativistic binary system emits gravitational radiation, causing the system to lose energy and slowly spiral inwards.	background 1.00	0.05	0.03	asserted 1.00
s2	However, since inspiral occurs on a time scale much longer than the orbital period, we can treat the binary to be in quasiequilibrium.	method 0.56	0.18	0.04	asserted 0.99
s3	In this approximation, we integrate a subset of the Einstein equations coupled to the relativistic equation of hydrostatic equilibrium to solve the initial value problem for binaries of arbitrary separation.	method 1.00	0.94	0.04	asserted 0.99
s4	We adopt a polytropic equation of state to determine the structure and maximum mass of neutron stars in close binaries for polytropic indices n=1, 1.5 and 2.	method 0.99	0.93	0.04	asserted 0.98
s5	We construct sequences of constant rest-mass and locate turning points along energy equilibrium curves to identify the onset of orbital instability.	method 0.97	0.96	0.06	asserted 0.99
s6	In particular, we locate the innermost stable circular orbit (ISCO) and its angular velocity.	result 0.66	0.96	0.10	asserted 1.00
s7	We construct the first contact binary systems in full general relativity.	contribution 0.53	0.96	0.13	asserted 1.00
s8	These arise whenever the equation of state is sufficiently soft >= 1.5.	result 0.98	0.83	0.11	asserted 0.97
s9	A radial stability analysis reveals no tendency for neutron stars in close binaries to collapse to black holes prior to merger.	result 0.98	0.93	0.40	asserted 0.97

What kind of paper the classifier reports this is: simulation study 0.97 · evidence from simulation or computation 1.00.

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arXiv listing abstract v1

not examined

full text
figures and tables
references and citing sentences
relations to other papers

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P abstract

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S sections
T body sentences
C citations
R cross-paper relations

Every quoted sentence on this record is the authors'. Every label is from Pith's closed vocabulary, with the probability shown beside it. Every number in the measurements table is the authors', checked by code. Record as JSON

The paper

Original abstract

We perform fully relativistic calculations of binary neutron stars in corotating, circular orbit. While Newtonian gravity allows for a strict equilibrium, a relativistic binary system emits gravitational radiation, causing the system to lose energy and slowly spiral inwards. However, since inspiral occurs on a time scale much longer than the orbital period, we can treat the binary to be in quasiequilibrium. In this approximation, we integrate a subset of the Einstein equations coupled to the relativistic equation of hydrostatic equilibrium to solve the initial value problem for binaries of arbitrary separation. We adopt a polytropic equation of state to determine the structure and maximum mass of neutron stars in close binaries for polytropic indices n=1, 1.5 and 2. We construct sequences of constant rest-mass and locate turning points along energy equilibrium curves to identify the onset of orbital instability. In particular, we locate the innermost stable circular orbit (ISCO) and its angular velocity. We construct the first contact binary systems in full general relativity. These arise whenever the equation of state is sufficiently soft >= 1.5. A radial stability analysis reveals no tendency for neutron stars in close binaries to collapse to black holes prior to merger.

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Cited by 2 Pith papers

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score. Full citation record

A comprehensive simulation framework for multi-modal kilonova observations from all-sky surveys
astro-ph.IM 2026-10 conditional novelty 5.0 of 10

A multimodal kilonova simulation pipeline produces survey-realistic light curves, spectra, and image pairs intended for training AI classifiers and parameter estimators.
Binary neutron-star mergers: a review of Einstein's richest laboratory
gr-qc 2016-07 accept novelty 2.0 of 10

A comprehensive 2016 survey of binary neutron-star merger simulations, covering numerical methods, initial data, post-merger dynamics, magnetic fields, ejecta and nucleosynthesis, with the field's open questions catalogued.

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10 arXiv papers cite this in 11 sentences

Each citing sentence is taken from the citing paper's LaTeX source and typed by Pith's classifier. A label appears at probability 0.8 or more (0.95 for support), a contest at 0.7 or more; the quoted words are the citing authors'. How each label was checked · JSON

Papers whose main result relates to this one's

Found among the papers closest to this one by title and main claim. Pith's classifier compared each pair's main results and a second model family confirmed the relation; checked against two further families, shown conflicts agreed 118 times in 120 and shown same results 218 times in 239. The quoted sentence is the other paper's main claim.

States the same result 3 papers

Thus, no tendency is found for the stars to individually collapse to black hole prior to merger.

Numerical models of irrotational binary neutron stars in general relativity · 0.99
We find that inspiraling binary neutron stars are stable against radial collapse to black holes all the way down to the innermost stable circular orbit.

The Stability of Relativistic Neutron Stars in Binary Orbit · 0.98
These results, in combination with previous analyses of Newtonian tidal interactions, indicate that (i) there are no large general-relativistic crushing forces that could cause the stars to collapse to black holes prior to the dynamical orbital instability, and (ii) the conventional wisdom with respect to coalescing binary neutron stars as sources of gravitational-wave bursts is correct: namely, the finite-stellar-size corrections to the gravitational waveform will be unimportant for the purpose of detecting the coalescences.

General-relativistic coupling between orbital motion and internal degrees of freedom for inspiraling binary neutron stars · 0.86

Papers citing it · 5 sentences without a confident label

Uses its method or tool 1 paper

Among the spinning configurations we include two cases that have the same circulation, ADM mass, and angular velocity, but one is constructed with the corotation formalism described in Ref. [ref] , and the other with the constant rotational-velocity formalism.

Binary neutron star mergers: Effects of spin and post-merger dynamics · Initial conditions · 0.93

Cites it as background 5 papers

Tidal effects on the gravitational waveform in circular neutron star (NS) binary inspirals have been studied extensively [ref] , including quasi-equilibrium tides [ref] and resonant tides [ref] .

Evolution of inspiralling neutron star binaries: effects of tidal interactions and orbital eccentricities · Introduction · 0.96
The first such binary initial data were calculated by Baumgarte et al. [ref] and Marronetti et al. [ref] and described two NSs tidally locked, as for example the Earth-Moon system.

Constant circulation sequences of binary neutron stars and their spin characterization · Introduction · 0.91
The first calculations of NS–NS QE sequences, in both cases for synchronized binaries, were performed by Wilson, Mathews, and Marronetti [ref] and Baumgarte et al. [ref] .

Binary Neutron Star Mergers · Numerical implementations · 0.84

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