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A 3+1 Computational Scheme for Dynamic Spherically Symmetric Black Hole Spacetimes -- II: Time Evolution

General Relativity and Quantum Cosmology · Submitted 6 Jun 1999

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

The authors' main claim We present numerical black hole + scalar field evolutions showing that this scheme is stable, can evolve "forever" (we have gone to t > 4000m), and is very accurate.

how it is stated · asserted 1.00 read the record →

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arXiv IDgr-qc/9906022 (version 2)
Pith IDMAL2WV6B, Pith's permanent record of this paper and its review
CitationJonathan Thornburg. "A 3+1 Computational Scheme for Dynamic Spherically Symmetric Black Hole Spacetimes -- II: Time Evolution." arXiv:gr-qc/9906022 (1999). https://pith.science/paper/MAL2WV6B
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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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Compiled by classifier-1.13-20260917 via OpenRouter, question bank abstract-p1-20260923, 2026-09-23: 1 request, 8,512 input tokens, $0.0004 reported.

What the abstract itself states, as probabilities: claims first 0.02 · states limitation 0.56 · human participants 0.01 · controlled comparison 0.02 · randomized assignment 0.01 · states quantitative result 0.98 · compares with prior results 0.08 · mentions code or data availability 0.02.

The abstract, sentence by sentence

arXiv listing abstract v2. Results and the main claim are underlined; .

This is the second in a series of papers describing a 3+1 computational scheme for the numerical simulation of dynamic black hole spacetimes. We discuss the numerical time-evolution of a given black-hole-containing initial data slice in spherical symmetry. We avoid singularities via the "black-hole exclusion" or "horizon boundary condition" technique, where the slices meet the black hole's singularity, but on each slice a spatial neighbourhood of the singularity is excluded from the domain of the numerical computations. After first discussing some of the key design choices which arise with the black hole exclusion technique, we then give a detailed description of our numerical evolution scheme for spherically symmetric scalar field evolution, assuming that a black hole is already present on the initial slice. We use a free evolution, with Eddington-Finkelstein-like coordinates and the inner boundary placed at a fixed coordinate radius well inside the horizon. Our numerical scheme is based on the method of lines (MOL), where spacetime PDEs are first finite differenced in space only, yielding a system of coupled ODEs for the time evolution of the field variables along the spatial-grid-point world lines. These ODEs are then time-integrated by standard methods. We use 4th order finite differencing in both space and time, with 5 and/or 6 point spatial molecules (off-centered near the grid boundaries), and a Runge-Kutta time integrator. The spatial grid is smoothly nonuniform, but not adaptive. We present numerical black hole + scalar field evolutions showing that this scheme is stable, can evolve "forever" (we have gone to t > 4000m), and is very accurate. At a resolution Delta_r/r = 3% near the horizon, typical errors in g_ij(K_ij) at t=100m are <= 1e-5(3e-7), and the energy constraint is < 3e-5.

background contribution method result interpretation main claim

What the classifier reports for each sentence. The number is the probability it gave the label.
#sentencerolethe authors' own workstates the main conclusionstrength
s0 This is the second in a series of papers describing a 3+1 computational scheme for the numerical simulation of dynamic black hole spacetimes. background 0.95 0.23 0.03 asserted 0.99
s1 We discuss the numerical time-evolution of a given black-hole-containing initial data slice in spherical symmetry. contribution 0.93 0.69 0.04 asserted 0.78
s2 We avoid singularities via the "black-hole exclusion" or "horizon boundary condition" technique, where the slices meet the black hole's singularity, but on each slice a spatial neighbourhood of the singularity is excluded from the domain of the numerical computations. method 0.98 0.60 0.06 asserted 1.00
s3 After first discussing some of the key design choices which arise with the black hole exclusion technique, we then give a detailed description of our numerical evolution scheme for spherically symmetric scalar field evolution, assuming that a black hole is already present on the initial slice. contribution 0.53 0.78 0.04 asserted 0.78
s4 We use a free evolution, with Eddington-Finkelstein-like coordinates and the inner boundary placed at a fixed coordinate radius well inside the horizon. method 1.00 0.89 0.04 asserted 1.00
s5 Our numerical scheme is based on the method of lines (MOL), where spacetime PDEs are first finite differenced in space only, yielding a system of coupled ODEs for the time evolution of the field variables along the spatial-grid-point world lines. method 1.00 0.88 0.04 asserted 1.00
s6 These ODEs are then time-integrated by standard methods. method 1.00 0.76 0.02 asserted 0.99
s7 We use 4th order finite differencing in both space and time, with 5 and/or 6 point spatial molecules (off-centered near the grid boundaries), and a Runge-Kutta time integrator. method 1.00 0.93 0.03 asserted 1.00
s8 The spatial grid is smoothly nonuniform, but not adaptive. method 0.91 0.88 0.03 asserted 1.00
s9 We present numerical black hole + scalar field evolutions showing that this scheme is stable, can evolve "forever" (we have gone to t > 4000m), and is very accurate. result 0.99 0.97 0.70 asserted 1.00
s10 At a resolution Delta_r/r = 3% near the horizon, typical errors in g_ij(K_ij) at t=100m are <= 1e-5(3e-7), and the energy constraint is < 3e-5. result 1.00 0.96 0.27 asserted 1.00

What kind of paper the classifier reports this is: method or tool 0.84 · evidence from simulation or computation 1.00.

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not examined
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  • figures and tables
  • references and citing sentences
  • relations to other papers
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  • C citations
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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

This is the second in a series of papers describing a 3+1 computational scheme for the numerical simulation of dynamic black hole spacetimes. We discuss the numerical time-evolution of a given black-hole-containing initial data slice in spherical symmetry. We avoid singularities via the "black-hole exclusion" or "horizon boundary condition" technique, where the slices meet the black hole's singularity, but on each slice a spatial neighbourhood of the singularity is excluded from the domain of the numerical computations. After first discussing some of the key design choices which arise with the black hole exclusion technique, we then give a detailed description of our numerical evolution scheme for spherically symmetric scalar field evolution, assuming that a black hole is already present on the initial slice. We use a free evolution, with Eddington-Finkelstein-like coordinates and the inner boundary placed at a fixed coordinate radius well inside the horizon. Our numerical scheme is based on the method of lines (MOL), where spacetime PDEs are first finite differenced in space only, yielding a system of coupled ODEs for the time evolution of the field variables along the spatial-grid-point world lines. These ODEs are then time-integrated by standard methods. We use 4th order finite differencing in both space and time, with 5 and/or 6 point spatial molecules (off-centered near the grid boundaries), and a Runge-Kutta time integrator. The spatial grid is smoothly nonuniform, but not adaptive. We present numerical black hole + scalar field evolutions showing that this scheme is stable, can evolve "forever" (we have gone to t > 4000m), and is very accurate. At a resolution Delta_r/r = 3% near the horizon, typical errors in g_ij(K_ij) at t=100m are <= 1e-5(3e-7), and the energy constraint is < 3e-5.

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4 arXiv papers cite this in 7 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 citing it · 2 sentences without a confident label

Uses its method or tool 1 paper
Cites it as background 1 paper
  • Excision, as suggested by Unruh to Thornburg [ref] and developed by many authors, see [ref] for a selection, relies on the idea that nothing can escape from the black hole region, so it should be possible to simply remove that region from the computational domain without affecting the domain of outer communication whatsoever.

    An Implementation of DF-GHG with Application to Spherical Black Hole Excision · Introduction · 0.97

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