Anisotropic Stars in General Relativity

M. K. Mak; T. Harko

RECORD

Anisotropic Stars in General Relativity

M. K. Mak, T. Harko

General Relativity and Quantum Cosmology · Submitted 24 Oct 2001

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

The authors' main claim Numerical results show that the basic physical parameters (mass and radius) of the model can describe realistic astrophysical objects like neutron stars.

how it is stated · asserted 0.59 read the record →

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The compiled record

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, 3,521 input tokens, $0.0001 reported.

What the abstract itself states, as probabilities: claims first 0.03 · states limitation 0.09 · human participants 0.01 · controlled comparison 0.02 · randomized assignment 0.01 · states quantitative result 0.10 · compares with prior results 0.05 · mentions code or data availability 0.02.

The abstract, sentence by sentence

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

We present a class of exact solutions of Einstein's gravitational field equations describing spherically symmetric and static anisotropic stellar type configurations. The solutions are obtained by assuming a particular form of the anisotropy factor. The energy density and both radial and tangential pressures are finite and positive inside the anisotropic star. Numerical results show that the basic physical parameters (mass and radius) of the model can describe realistic astrophysical objects like neutron stars.

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 present a class of exact solutions of Einstein's gravitational field equations describing spherically symmetric and static anisotropic stellar type configurations.	contribution 1.00	0.95	0.31	asserted 1.00
s1	The solutions are obtained by assuming a particular form of the anisotropy factor.	method 1.00	0.92	0.04	asserted 1.00
s2	The energy density and both radial and tangential pressures are finite and positive inside the anisotropic star.	result 1.00	0.87	0.20	asserted 1.00
s3	Numerical results show that the basic physical parameters (mass and radius) of the model can describe realistic astrophysical objects like neutron stars.	result 0.59	0.93	0.53	asserted 0.59

What kind of paper the classifier reports this is: theoretical result 1.00 · evidence from proof or derivation 0.96.

What was examined, and what was not

sources read

arXiv listing abstract v2

not examined

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

levels run

P abstract

not run

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 present a class of exact solutions of Einstein's gravitational field equations describing spherically symmetric and static anisotropic stellar type configurations. The solutions are obtained by assuming a particular form of the anisotropy factor. The energy density and both radial and tangential pressures are finite and positive inside the anisotropic star. Numerical results show that the basic physical parameters (mass and radius) of the model can describe realistic astrophysical objects like neutron stars.

Human review

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References

Forward citations

Cited by 4 Pith papers

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

Probing the Unstable Spectrum of Schwarzschild-like Black Holes
gr-qc 2025-01 conditional novelty 6.0 of 10

The quasinormal mode spectrum of physically deformed Schwarzschild-like black holes stays unstable, contradicting the expectation that displaced spectra become stable.
Anisotropic stars as ultracompact objects in General Relativity
gr-qc 2018-11 conditional novelty 6.0 of 10

Anisotropic stars built from a covariant pressure-anisotropy closure can reach black-hole compactness, remain nonlinearly stable below the maximum mass, and produce gravitational-wave echoes.
Anisotropic quantum polytropes
gr-qc 2025-06 reject novelty 5.0 of 10

In pressureless quantum polytropes, positive pressure anisotropy compresses the structure and stronger gravity weakens binding, opposite to classical polytrope behavior.
Hairy black holes by gravitational decoupling
gr-qc 2020-06 conditional novelty 4.0 of 10

By deforming the Schwarzschild metric with a generic extra source, the authors construct hairy black hole solutions that satisfy the strong or dominant energy condition and carry a new charge that increases the horizo...

How the literature uses it

30 arXiv papers cite this in 33 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 1 paper

Numerical results show that the basic physical parameters (mass and radius) of the model can describe realistic astrophysical objects like neutron stars.

Anisotropic relativistic stellar models · 1.00

Papers citing it · 20 sentences without a confident label

Uses its method or tool 1 paper

To derive the Lagrangian, we rewrite the stress-energy tensor by following Ref. [ref] , [equation] where $u^μ=f^-1/2(r)δ^μ_0$ is timelike four-velocity with normaliztion $g_μνu^μu^ν=-1$; $χ^μ=f^1/2(r)δ^μ_1$ is unit spacelike vector in the radial direction, arising from the anisotropic character of the source.

Quasinormal Modes and Thermodynamics of Regular Black Holes · The Lagrangian for the anisotropic fluid · 0.99

Cites it as background 12 papers

[ref] were obtained an exact solution of Einstein field equations, describing spherically symmetric and static anisotropic stellar configuration, by assuming a particular form of anisotropic factor.

On the features of Matese-Whitman mass function · Introduction · 0.86
In the scope of General Relativity we can find a vast number of works studying the influence of the anisotropy on static spherically symmetric objects composed of a perfect fluid (review [ref] and references therein).

Radial stability of anisotropic strange quark stars · Introduction · 1.00
Substantial progresses have been done in the analysis of anisotropic relativistic star solutions, using both analytical [ref] and numerical techniques [ref] .

Primordial black hole formation for an anisotropic perfect fluid: Initial conditions and estimation of the threshold · Introduction · 0.99

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