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REVIEW 4 major objections 5 minor 77 references

Investigating Universal Relations in Compact Stars featuring $\Delta-$Admixed Exotic Dense Matter

T0 review · 4 major / 5 minor · reviewed 2026-08-06 · deepseek-v4-flash

Pith's one-line read Baryonic stars whose cores contain hyperons and Delta resonances still obey the EOS-independent I-Love-Q relations, and their f-mode oscillation frequency tracks tidal deformability to within 0.07 percent in full general relativity.

desk verdict Competent extension of the I-Love-Q and f-mode universality program to Delta-admixed hypernuclear EOS; the f-mode result is clean, but the I-Love-Q part needs a slow-rotation check before the claim is fully persuasive. read the letter →

arxiv 2507.11956 v1 pith:TOQTFA75 submitted 2025-07-16 astro-ph.HE hep-ph

classification astro-ph.HEhep-ph
keywords I-Love-Qrelationstidaldeformabilityf-modeoscillationsp-modeDeltaresonanceshyperonsequationofstateneutronstars
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

The paper asks whether the celebrated EOS-independent relations among neutron-star bulk properties survive when the stellar core contains not just nucleons but also hyperons and $\Delta$ resonances. Working with three covariant density functionals (DD-ME2, DD-MEX, DD2) that include the full baryon octet and $\Delta$ states, it computes moment of inertia, tidal deformability, quadrupole moment, and the quadrupolar f- and p-mode quasinormal frequencies. The authors find that the I-Love-Q relations still hold, with polynomial fits having $R^{2}$ ~0.999 and scatter of a few percent, and that the dimensionless f-mode frequency correlates with tidal deformability to a maximum deviation of about 0.07% in full general relativity. The p-mode relation, by contrast, scatters by more than 14%, so it is not universal. If correct, the result means gravitational-wave measurements of tides can be used to predict the fundamental oscillation frequency of exotic-composition stars without knowing the dense-matter model.

What carries the argument

The working machinery is the covariant density functional description of dense matter, a relativistic mean-field model with density-dependent couplings from the DD-ME2, DD-MEX, and DD2 parameter sets, extended to a full baryon octet (nucleons, Lambda, Sigma, Xi) plus $\Delta$ resonances in $\beta$ equilibrium with leptons. Stellar structures for rotating configurations are computed with a general-relativistic numerical solver at a fixed rotation frequency of 480 Hz, from which the dimensionless moment of inertia, quadrupole moment, and tidal deformability are extracted. Quasinormal f- and p-mode frequencies are obtained by direct numerical integration of the linearized Einstein-fluid perturbation equations for l=2 even-parity modes. Everything is condensed into fourth-order polynomial fits in log space, with coefficients tabulated, and fit quality reported as the coefficient of determination $R^{2}$.

What would settle it

Recompute the inertia-quadrupole, inertia-tidal, and quadrupole-tidal scatter for the same three equations of state across a range of rotation frequencies from near zero up to the mass-shedding limit; if the points at 480 Hz separate from the non-rotating curves by more than the few-percent bands the paper reports, or if a new exotic EOS placed on the same plot falls off the fitted curves by more than those bands, the claimed universality would be rotation-dependent or model-dependent rather than universal.

Watch

Extended reading notes

Core claim

The central claim is that baryonic stars whose cores contain heavier baryons—hyperons and $\Delta$ resonances—still obey the same universal relations established for purely nucleonic stars. Concretely, the paper shows that the dimensionless moment of inertia, spin-induced quadrupole moment, and tidal Love number collapse onto common polynomial fits across the three density functionals, with maximum deviations of about 4.65% for the quadrupole-tidal relation, 1.56% for the inertia-tidal relation, and within 5% for the inertia-quadrupole relation. The paper's strongest quantitative result is the f-mode behavior: the dimensionless fundamental-mode frequency plotted against tidal deformability follows a single curve with a maximum deviation near 0.07% when computed in full general relativity. The first pressure mode does not share this behavior, showing $R^{2}$ ~0.9684 and deviations exceeding 14%, which the authors interpret as making p-modes useful composition probes. The paper frames this as an extension of universality from nucleonic matter to $\Delta$-admixed hypernuclear matter.

Load-bearing premise

The whole analysis assumes that computing the moment of inertia and quadrupole moment at a fixed spin of 480 Hz is indistinguishable, for universal-relation purposes, from the non-rotating limit; the paper itself notes that its inertia-quadrupole curve deviates from the benchmark fit at large quadrupole moments and attributes the offset to this rotation choice (Section 3.1, Figure 1).

Editorial extensions

If this is right

  • A gravitational-wave measurement of tidal deformability during inspiral would, through the f-mode-Lambda relation, predict the dominant oscillation frequency of an exotic-core remnant to better than 0.1%.
  • Multimessenger inference of moment of inertia and quadrupole moment from X-ray timing can be cross-checked against tidal deformability from mergers without knowing whether the star contains hyperons or Deltas.
  • The p-mode relation is not universal across these equations of state, so observed p-mode frequencies would carry information about the presence of exotic baryons rather than serving as a clean probe of bulk properties.
  • The three density functionals, calibrated to finite nuclei and heavy-ion constraints, all lie on the same universal curves, so the relations are robust against the specific choice of the relativistic mean-field parameterization.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • Editorial inference: the paper's own observation that the 480-Hz inertia-quadrupole fit departs from the benchmark at large quadrupole moments suggests that rotation, not exotic composition, is the practical ceiling on I-Love-Q universality; testing at slower spin would quantify that ceiling.
  • Editorial inference: because the f-mode-Lambda relation is so tight, combining a single f-mode detection in a post-merger gravitational-wave signal with an inspiral tidal measurement would test general relativity in the strong-field regime with an EOS-independent lever arm.
  • Editorial inference: the weak p-mode correlation opens a concrete observational strategy—resonant searches for p-modes would be a direct handle on Delta and hyperon content, complementing the composition-blind f-modes.
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Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

4 major / 5 minor

Summary. The paper investigates whether neutron stars described by three covariant density functional equations of state (DD-ME2, DD-MEX, DD2) that include hyperons and Delta resonances obey the well-known I-Love-Q universal relations and the empirical correlations between non-radial oscillation frequencies and tidal deformability. Using the RNS code for rotating configurations at a fixed 480 Hz spin frequency, the authors compute the moment of inertia and quadrupole moment, and they compute tidal deformability and f-/p-mode quasinormal mode frequencies in full general relativity. Polynomial fits are reported for ln I - ln Q, ln I - ln Lambda, ln Q - ln Lambda, omega_f - Lambda, and omega_p - Lambda, with very high R^2 values for all but the p-mode relation. The paper concludes that baryonic stars with heavier-baryon cores follow the universal relations, with the f-mode relation showing a maximum fit deviation of about 0.07%.

Significance. If established, the result would extend the I-Love-Q and f-mode universal relations to dense matter with hyperons and Delta resonances, which is a nontrivial extension because exotic degrees of freedom soften the equation of state and can affect stellar structure. The study uses standard numerical methods, and the f-mode part of the analysis, which is computed for nonrotating stars in full general relativity, is a clean and useful confirmation for three well-motivated EOS parameterizations. The I-Love-Q part, however, is compromised by the use of a fixed 480 Hz rotation frequency rather than the slow-rotation limit in which the canonical relations are defined.

major comments (4)
  1. [Section 3.1, first paragraph and Figure 1] The canonical I-Love-Q relations are defined for the nonrotating moment of inertia, the spin-induced quadrupole moment at second order in the spin, and the nonrotating tidal deformability. Here I and Q are computed with the RNS code at a fixed spin frequency of 480 Hz, which is not the slow-rotation limit. The paper itself acknowledges 'noticeable differences at high quadrupole moments compared to the YY fit' and attributes them to the different rotational frequencies, which is exactly the signature of a rotation-dependent shift rather than a test of the canonical universal relation. The claim that these stars 'follow the universal relations' is therefore not established by the I-Q, I-Lambda, and Q-Lambda data as presented.
  2. [Section 3.1, paragraph on rotational frequency] The assertion that 480 Hz is 'much lower than the corresponding Kepler limit, ensuring minimal rotational influence' is not quantitatively supported. The Kepler frequency varies along the mass sequence and between EOSs, and for low-mass stars 480 Hz can be a sizable fraction of the Kepler frequency. The paper should provide mass-dependent Kepler frequencies, the typical dimensionless spin parameter chi, and a quantitative estimate of the difference between the 480 Hz values of I and Q and their slow-rotation limits (for example, by comparing with Hartle-Thorne calculations). Without this, the reported 5% maximum deviation in the I-Q relation and the deviations from the YY fit cannot be separated from rotational systematics.
  3. [Table 2 and Section 3.1] The fit coefficients are reported without uncertainties, and the R^2 values are given without error bars or the number of data points per EOS. Since the central quantitative claims are residuals at the level of 0.07% for the f-mode and a few percent for the I-Love-Q relations, the fits need standard errors or confidence intervals to be assessable. The reader should also be told how many stellar models enter each fit and over which mass range.
  4. [Abstract and Section 3.1] The abstract states an 'error margin under 1%' for the f-mode universality, while the text reports a maximum deviation of about 0.07%. This is internally consistent, but the phrasing is misleading: the 0.07% is the deviation from the authors' own polynomial fit to their own data, not a comparison with an established universal relation in the literature. The manuscript should clarify what 'error margin' means and should compare the fitted relation against previously published f-mode-Lambda fits, not only against an internal fit.
minor comments (5)
  1. [Throughout] The text uses 'R' and 'R^2' interchangeably for the coefficient of determination; for consistency this should be R^2 throughout.
  2. [Equation (3)] The boundary-condition equation contains formatting artifacts (e.g., a stray 'nh' and inconsistent superscripts) that make it difficult to read; it should be typeset cleanly.
  3. [Table 2] The coefficient columns are given in mixed units (some with powers of 10 in the header, some without), which invites transcription errors; all coefficients should be presented on a uniform scale with explicit uncertainties.
  4. [Section 3.1] The statement 'Due to limitations of the RNS code, these quantities are computed at a fixed frequency of 480 Hz' is not self-explanatory; the relevant numerical limitation should be stated explicitly.
  5. [Figure 1] The inset shows a 5% error threshold, but it is unclear whether this is an absolute or relative error on ln I; the caption should define the fractional error precisely.

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity: the universal relations are empirical fits to independently computed stellar properties, with the Yagi-Yunes fit serving as an external benchmark.

full rationale

The paper's central claims are that I-Love-Q and f-mode frequency relations hold for EOSs with hyperons and Delta resonances. These relations are empirical: I, Q, Lambda, and the QNM frequencies are computed directly from stellar structure and perturbation equations, and the polynomial fits in Table 2 are then applied to those data. The fit coefficients are not used to construct the EOS, set boundary conditions, or define the computed quantities, so the small residuals (R^2 ~ 0.999, f-mode deviation ~0.07%) are not forced by construction. The comparison to the Yagi-Yunes fit provides an external benchmark, and the paper explicitly reports deviations at high Q, attributing them to the fixed 480 Hz rotation; whether that attribution is correct is a physical-validity question, not a circularity. The EOS formalism and exotic-meson couplings are taken from Ref. [13] by the same authors, which is a normal methodological self-citation: it supplies inputs, not the universal-relation conclusion, and nothing in the derivation reduces the target claim to that citation. The paper also notes the RNS-code limitation of computing at 480 Hz (Section 3.1), which is a modeling caveat rather than a circular step. No step in the paper defines a predicted quantity in terms of a fitted parameter, nor imports a uniqueness or ansatz from prior work to forbid alternatives. Hence no circular step is present.

Assumptions & free parameters 2 free parameters · 4 assumptions · 0 invented entities

The central claim rests on the specific EOS models and numerical solvers adopted; the paper does not derive the EOS from first principles but imports coupling parameters from prior work, and the universal relations are extracted as fits to computed data.

free parameters (2)
  • Rotation frequency for I and Q computation = 480 Hz
    All moment of inertia and quadrupole moment values are computed at a fixed rotation frequency of 480 Hz for all EOS, which is a user choice; the paper states this differs from the YY fit and affects the extracted I-Q relation at high Q.
  • Hyperon and Delta meson-baryon couplings = from Ref. [13]
    The couplings for hyperons and Delta resonances are adopted from a prior paper by the same authors; they determine the onset density and abundance of exotic baryons and therefore shape the EOS and the stellar properties used in the universal relations.
assumptions (4)
  • domain assumption The DD-ME2, DD-MEX, and DD2 covariant density functionals accurately describe dense matter at supranuclear densities.
    The paper relies on these three parameter sets as representative EOS without independent verification of their high-density behavior.
  • domain assumption The hyperon and Delta interaction couplings from Ref. [13] are physically appropriate.
    The EOS for exotic baryons is imported from the authors' earlier work, and the validity of the universal relation claim depends on these couplings producing realistic stellar solutions.
  • standard math The RNS code and the direct numerical integration method correctly solve the Einstein equations and perturbed fluid equations for the considered models.
    The paper uses established numerical tools; no code or validation details are provided, so correctness is assumed from the literature.
  • standard math The universal relations are defined through the standard dimensionless combinations I/M^3, Q/(M^3 chi^2), Lambda, and omega M.
    The paper adopts the conventional definitions from Yagi and Yunes without modification.

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Cite this review

Pith. "Pith review of Investigating Universal Relations in Compact Stars featuring $\Delta-$Admixed Exotic Dense Matter." pith.science (2026). https://pith.science/paper/TOQTFA75

@misc{pith2026250711956,
  author       = {Pith},
  title        = {Pith review of: Investigating Universal Relations in Compact Stars featuring $\Delta-$Admixed Exotic Dense Matter},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/TOQTFA75}},
  note         = {Machine review of arXiv:2507.11956}
}
abstract

The dense material in a compact star from a supernova remnant is beyond terrestrial experimentation, so phenomenological modeling is used to match astrophysical observations. This is crucial due to the complex sensitivity of compact star features to dense matter properties. Despite modeling flexibility, certain universal relationships among compact star features hold true, regardless of the matter model. Our study examines these universal relationships, focusing on the moment of inertia, tidal Love number, and quadrupole moment, as well as correlations between non-radial oscillation frequencies and star compactness. We consider baryonic stars with cores of heavier baryons. Our findings show that baryonic stars with cores of heavier baryons follow the universal relations, and the f-mode oscillation frequency's universality relative to tidal deformability is notable, with an error margin under 1$\%$.

Figures

Figures reproduced from arXiv: 2507.11956 by the authors.

Figure 1
Figure 1. The I−Q relations are presented alongside the corresponding analytic fit and the fractional error associated with the fitting function. The solid line represents the best-fit curve encompassing all data points. The inset plot illustrates the fractional errors, with the dashed line marking a 5% error threshold. The EOS compositions considered in this analysis are denoted as NY for hypernuclear matter and NY d for ∆-a… view at source ↗
Figure 2
Figure 2. Universal relations for compact stars, with the upper panel depicting the cor [PITH_FULL_IMAGE:figures/full_fig_p014_2.png] view at source ↗
Figure 3
Figure 3. Similar to Figs.- 1 & 2, but for the correlation fits for ¯ω [PITH_FULL_IMAGE:figures/full_fig_p015_3.png] view at source ↗

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Works this paper leans on

77 extracted references · 30 canonical work pages

  1. [13]

    V. B. Thapa, A. Kumar, M. Sinha, Baryonic dense matter in view of gravitational-wave observations, Mon. Not. Roy. Astron. Soc.507 (2) (2021) 2991–3004. arXiv:2108.04318, doi:10.1093/mnras/stab2327

  2. [1]

    N. K. Glendenning, S. A. Moszkowski, Reconciliation of neutron-star masses and binding of the Lambda in hypernuclei, Phys. Rev. Lett.67 (1991) 2414–1417. doi:10.1103/PhysRevLett.67.2414

  3. [2]

    Colucci, A

    G. Colucci, A. Sedrakian, Equation of state of hypernuclear matter: Impact of hyperon-scalar-meson couplings, Phys. Rev. C87 (5) (2013) 055806. arXiv:1302.6925, doi:10.1103/PhysRevC.87.055806

  4. [3]

    Oertel, C

    M. Oertel, C. Providˆ encia, F. Gulminelli, A. R. Raduta, Hyperons in neutron star matter within relativistic mean-field models, Journal of Physics G Nuclear Physics 42 (7) (2015) 075202. arXiv:1412.4545, doi:10.1088/0954-3899/42/7/075202. 17

  5. [4]

    A. R. Raduta, A. Sedrakian, F. Weber, Cooling of hypernuclear com- pact stars, Mon. Not. Roy. Astron. Soc.475 (4) (2018) 4347–4356. arXiv:1712.00584, doi:10.1093/mnras/stx3318

  6. [5]

    J. J. Li, W. H. Long, A. Sedrakian, Hypernuclear stars from relativistic Hartree-Fock density functional theory, European Physical Journal A 54 (8) (2018) 133. doi:10.1140/epja/i2018-12566-6

  7. [6]

    L. L. Lopes, D. P. Menezes, Broken SU(6) symmetry and massive hybrid stars, Nucl. Phys. A1009 (2021) 122171. arXiv:2004.07909, doi:10.1016/j.nuclphysa.2021.122171

  8. [7]

    Drago, A

    A. Drago, A. Lavagno, G. Pagliara, D. Pigato, Early appearance of ∆ isobars in neutron stars, Phys. Rev. C90 (6) (2014) 065809. doi:10.1103/PhysRevC.90.065809

Show all 77 references
  1. [8]

    B.-J. Cai, F. J. Fattoyev, B.-A. Li, W. G. Newton, Critical density and impact of ∆ (1232 ) resonance formation in neu- tron stars, Phys. Rev. C92 (1) (2015) 015802. arXiv:1501.01680, doi:10.1103/PhysRevC.92.015802

  2. [9]

    J. J. Li, A. Sedrakian, F. Weber, Competition between delta isobars and hyperons and properties of compact stars, Physics Letters B 783 (2018) 234–240. arXiv:1803.03661, doi:10.1016/j.physletb.2018.06.051

  3. [10]

    J. J. Li, A. Sedrakian, Implications from GW170817 for ∆-isobar Ad- mixed Hypernuclear Compact Stars, Astro. Phys. J. Lett.874 (2) (2019) L22. arXiv:1904.02006, doi:10.3847/2041-8213/ab1090

  4. [11]

    J. J. Li, A. Sedrakian, M. Alford, Relativistic Hybrid Stars with Sequential First-order Phase Transitions in Light of Multimessenger Constraints, Astro. Phys. J. 944 (2) (2023) 206. arXiv:2301.10940, doi:10.3847/1538-4357/acb688

  5. [12]

    Baruah Thapa, M

    V. Baruah Thapa, M. Sinha, J.-J. Li, A. Sedrakian, Equation of state of strongly magnetized matter with hyperons and ∆- resonances, arXiv e-prints (2020) arXiv:2010.00981arXiv:2010.00981, doi:10.48550/arXiv.2010.00981. 18

  6. [14]

    V. B. Thapa, M. Sinha, J. J. Li, A. Sedrakian, Massive ∆-resonance admixed hypernuclear stars with antikaon condensations, Phys. Rev. D 103 (2021) 063004. doi:10.1103/PhysRevD.103.063004. URL https://link.aps.org/doi/10.1103/PhysRevD.103.063004

  7. [15]

    Mannarelli, Meson Condensation, Particles 2 (3) (2019) 411–443

    M. Mannarelli, Meson Condensation, Particles 2 (3) (2019) 411–443. arXiv:1908.02042, doi:10.3390/particles2030025

  8. [16]

    Haensel, M

    P. Haensel, M. Proszynski, Pion condensation in cold dense matter and neutron stars, Astro. Phys. J. 258 (1982) 306–320. doi:10.1086/160080

  9. [17]

    N. K. Glendenning, J. Schaffner-Bielich, First order kaon conden- sate, Phys. Rev. C60 (2) (1999) 025803. arXiv:astro-ph/9810290, doi:10.1103/PhysRevC.60.025803

  10. [18]

    Banik, D

    S. Banik, D. Bandyopadhyay, Antikaon condensation and the metasta- bility of protoneutron stars, Phys. Rev. C63 (3) (2001) 035802. arXiv:astro-ph/0009113, doi:10.1103/PhysRevC.63.035802

  11. [19]

    V. B. Thapa, M. Sinha, Dense matter equation of state of a massive neutron star with antikaon condensation, Phys. Rev. D102 (12) (2020) 123007. arXiv:2011.06440, doi:10.1103/PhysRevD.102.123007

  12. [20]

    Baruah Thapa, M

    V. Baruah Thapa, M. Sinha, J. Jie Li, A. Sedrakian, Mas- sive ∆-resonance admixed hypernuclear stars with anti-kaon con- densations, arXiv e-prints (2021) arXiv:2102.08787arXiv:2102.08787, doi:10.48550/arXiv.2102.08787

  13. [21]

    Chodos, R

    A. Chodos, R. L. Jaffe, K. Johnson, C. B. Thorn, V. F. Weisskopf, New extended model of hadrons, Phys. Rev. D 9 (1974) 3471–3495. doi:10.1103/PhysRevD.9.3471. URL https://link.aps.org/doi/10.1103/PhysRevD.9.3471

  14. [22]

    Farhi, R

    E. Farhi, R. L. Jaffe, Strange matter, Phys. Rev. D30 (11) (1984) 2379–

  15. [23]

    Buballa, NJL-model analysis of dense quark matter [review ar- ticle], Phys

    M. Buballa, NJL-model analysis of dense quark matter [review ar- ticle], Phys. Rep.407 (4-6) (2005) 205–376. arXiv:hep-ph/0402234, doi:10.1016/j.physrep.2004.11.004

  16. [24]

    ’t Hooft, Symmetry breaking through bell-jackiw anomalies, Phys

    G. ’t Hooft, Symmetry breaking through bell-jackiw anomalies, Phys. Rev. Lett. 37 (1976) 8–11. doi:10.1103/PhysRevLett.37.8. URL https://link.aps.org/doi/10.1103/PhysRevLett.37.8

  17. [25]

    Nambu, G

    Y. Nambu, G. Jona-Lasinio, Dynamical Model of Elementary Particles Based on an Analogy with Superconductivity. 1., Phys. Rev. 122 (1961) 345–358. doi:10.1103/PhysRev.122.345

  18. [26]

    B. A. et al., Gw170817: Observation of gravitational waves from a binary neutron star inspiral, Phys. Rev. Lett. 119 (2017) 161101. doi:10.1103/PhysRevLett.119.161101. URL https://link.aps.org/doi/10.1103/PhysRevLett.119.161101

  19. [27]

    Lazio, The Square Kilometre Array, in: Panoramic Radio Astron- omy: Wide-field 1-2 GHz Research on Galaxy Evolution, 2009, p

    J. Lazio, The Square Kilometre Array, in: Panoramic Radio Astron- omy: Wide-field 1-2 GHz Research on Galaxy Evolution, 2009, p. 58. arXiv:0910.0632, doi:10.22323/1.089.0058

  20. [28]

    K. C. Gendreau, Z. Arzoumanian, P. W. Adkins, C. L. Albert, J. F. Anders, A. T. Aylward, C. L. Baker, E. R. Balsamo, W. A. Bamford, S. S. Benegalrao, D. L. Berry, S. Bhalwani, J. K. Black, C. Blaurock, G. M. Bronke, G. L. Brown, J. G. Budinoff, J. D. Cantwell, T. Cazeau, P. T....

  21. [29]

    Spiller, G

    P. Spiller, G. Franchetti, The fair accelerator project at gsi, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 561 (2) (2006) 305–309, proceedings of the Workshop on High Intensity Beam Dynam- ics....

  22. [30]

    Kekelidze, Nica project at jinr: status and prospects, Jour- nal of Instrumentation 12 (06) (2017) C06012

    V. Kekelidze, Nica project at jinr: status and prospects, Jour- nal of Instrumentation 12 (06) (2017) C06012. doi:10.1088/1748- 0221/12/06/C06012. URL https://dx.doi.org/10.1088/1748-0221/12/06/C06012

  23. [31]

    K. Yagi, N. Yunes, I-Love-Q relations in neutron stars and their applications to astrophysics, gravitational waves, and fundamen- tal physics, Phys. Rev. D88 (2) (2013) 023009. arXiv:1303.1528, doi:10.1103/PhysRevD.88.023009

  24. [32]

    K. Yagi, N. Yunes, I-Love-Q: Unexpected Universal Relations for Neutron Stars and Quark Stars, Science 341 (6144) (2013) 365–368. arXiv:1302.4499, doi:10.1126/science.1236462

  25. [33]

    Bejger, P

    M. Bejger, P. Haensel, Moments of inertia for neutron and strange stars: Limits derived for the Crab pulsar, Astronomy and Astro- physics396 (2002) 917–921. arXiv:astro-ph/0209151, doi:10.1051/0004- 6361:20021241

  26. [34]

    J. M. Lattimer, B. F. Schutz, Constraining the Equation of State with Moment of Inertia Measurements, Astro. Phys. J. 629 (2) (2005) 979–

  27. [35]

    Urbanec, J

    M. Urbanec, J. C. Miller, Z. Stuchl ´ ık, Quadrupole moments of rotating neutron stars and strange stars, Mon. Not. Roy. Astron. Soc.433 (3) (2013) 1903–1909. arXiv:1301.5925, doi:10.1093/mnras/stt858

  28. [36]

    Bandyopadhyay, S

    D. Bandyopadhyay, S. A. Bhat, P. Char, D. Chatterjee, Moment of in- ertia, quadrupole moment, Love number of neutron star and their rela- tions with strange-matter equations of state, European Physical Journal A 54 (2) (2018) 26. arXiv:1712.01715, doi:10.1140/epja/i2018-12456-y

  29. [37]

    A. R. Raduta, M. Oertel, A. Sedrakian, Proto-neutron stars with heavy baryons and universal relations, Mon. Not. Roy. Astron. Soc.499 (1) (2020) 914–931. arXiv:2008.00213, doi:10.1093/mnras/staa2491

  30. [38]

    Khosravi Largani, T

    N. Khosravi Largani, T. Fischer, A. Sedrakian, M. Cierniak, D. E. Alvarez-Castillo, D. B. Blaschke, Universal relations for rapidly rotating cold and hot hybrid stars, Mon. Not. Roy. Astron. Soc.515 (3) (2022) 3539–3554. arXiv:2112.10439, doi:10.1093/mnras/stac1916

  31. [39]

    Paschalidis, K

    V. Paschalidis, K. Yagi, D. Alvarez-Castillo, D. B. Blaschke, A. Sedrakian, Implications from GW170817 and I-Love-Q relations for relativistic hybrid stars, Phys. Rev. D97 (8) (2018) 084038. arXiv:1712.00451, doi:10.1103/PhysRevD.97.084038

  32. [40]

    Kunjipurayil, T

    A. Kunjipurayil, T. Zhao, B. Kumar, B. K. Agrawal, M. Prakash, Impact of the equation of state on f - and p - mode oscillations of neutron stars, Phys. Rev. D106 (6) (2022) 063005. arXiv:2205.02081, doi:10.1103/PhysRevD.106.063005

  33. [41]

    T. Zhao, J. M. Lattimer, Universal relations for neutron star f-mode and g-mode oscillations, Physical Review D 106 (12) (2022) 123002. doi:10.1103/PhysRevD.106.123002

  34. [42]

    Lozano, V

    N. Lozano, V. Tran, P. Jaikumar, Temperature Effects on Core g-Modes of Neutron Stars, Galaxies 10 (4) (2022) 79. doi:10.3390/galaxies10040079

  35. [43]

    V. B. Thapa, M. V. Beznogov, A. R. Raduta, P. Thakur, Frequencies of f - and p-oscillation modes in cold and hot compact stars, Phys. Rev. D 107 (2023) 103054. doi:10.1103/PhysRevD.107.103054. URL https://link.aps.org/doi/10.1103/PhysRevD.107.103054 22

  36. [44]

    Andersson, K

    N. Andersson, K. D. Kokkotas, Towards gravitational wave asteroseis- mology, Mon. Not. Roy. Astron. Soc.299 (4) (1998) 1059–1068. arXiv:gr- qc/9711088, doi:10.1046/j.1365-8711.1998.01840.x

  37. [45]

    Benhar, V

    O. Benhar, V. Ferrari, L. Gualtieri, Gravitational wave asteroseismol- ogy reexamined, Phys. Rev. D70 (12) (2004) 124015. arXiv:astro- ph/0407529, doi:10.1103/PhysRevD.70.124015

  38. [46]

    H. K. Lau, P. T. Leung, L. M. Lin, Inferring Physical Parameters of Compact Stars from their f-mode Gravitational Wave Signals, Astro. Phys. J. 714 (2) (2010) 1234–1238. arXiv:0911.0131, doi:10.1088/0004- 637X/714/2/1234

  39. [47]

    G. A. Lalazissis, T. Nikˇ si´ c, D. Vretenar, P. Ring, New relativistic mean- field interaction with density-dependent meson-nucleon couplings, Phys. Rev. C71 (2) (2005) 024312. doi:10.1103/PhysRevC.71.024312

  40. [48]

    Taninah, S

    A. Taninah, S. Agbemava, A. Afanasjev, P. Ring, Parametric corre- lations in energy density functionals, Physics Letters B 800 (2020) 135065. doi:https://doi.org/10.1016/j.physletb.2019.135065. URL https://www.sciencedirect.com/science/article/pii/S0370269319307877

  41. [49]

    Typel, G

    S. Typel, G. R¨ opke, T. Kl¨ ahn, D. Blaschke, H. H. Wolter, Composition and thermodynamics of nuclear matter with light clusters, Phys. Rev. C 81 (2010) 015803. doi:10.1103/PhysRevC.81.015803. URL https://link.aps.org/doi/10.1103/PhysRevC.81.015803

  42. [50]

    Oertel, M

    M. Oertel, M. Hempel, T. Kl¨ ahn, S. Typel, Equations of state for su- pernovae and compact stars, Reviews of Modern Physics 89 (1) (2017) 015007. arXiv:1610.03361, doi:10.1103/RevModPhys.89.015007

  43. [51]

    Kundu, V

    D. Kundu, V. B. Thapa, M. Sinha, (anti)kaon condensation in strongly magnetized dense matter, Phys. Rev. C 107 (2023) 035807. doi:10.1103/PhysRevC.107.035807. URL https://link.aps.org/doi/10.1103/PhysRevC.107.035807

  44. [52]

    K. S. Thorne, A. Campolattaro, Non-Radial Pulsation of General- Relativistic Stellar Models. I. Analytic Analysis for L ¿= 2, Astrophys- ical Journal, vol. 149, p.591 (Sep. 1967). doi:10.1086/149288. 23

  45. [53]

    Lindblom, S

    L. Lindblom, S. L. Detweiler, The quadrupole oscillations of neutron stars, Astrophysical Journal Supplement Series (ISSN 0067-0049), vol. 53, Sept. 1983, p. 73-92. 53 (1983) 73–92

  46. [54]

    Detweiler, L

    S. Detweiler, L. Lindblom, On the nonradial pulsations of general rela- tivistic stellar models, The Astrophysical Journal 292 (1985) 12–15

  47. [55]

    K. S. Thorne, Nonradial Pulsation of General-Relativistic Stellar Mod- els. III. Analytic and Numerical Results for Neutron Stars, Astro. Phys. J. 158 (1969) 1. doi:10.1086/150168

  48. [56]

    Chandrasekhar, V

    S. Chandrasekhar, V. Ferrari, On the non-radial oscillations of a star, Proceedings of the Royal Society of London Series A 432 (1885) (1991) 247–279. doi:10.1098/rspa.1991.0016

  49. [57]

    Sotani, K

    H. Sotani, K. Tominaga, K.-i. Maeda, Density discontinuity of a neutron star and gravitational waves, Physical Review D 65 (2) (2001) 024010. doi:10.1103/PhysRevD.65.024010

  50. [58]

    K. D. Kokkotas, B. F. Schutz, W-modes: a new fam- ily of normal modes of pulsating relativistic stars, Monthly Notices of the Royal Astronomical Society 255 (1) (1992) 119–128. arXiv:https://academic.oup.com/mnras/article- pdf/255/1/119/18523446/mnras255-0119.pdf, doi:10.1093/...

  51. [59]

    T. G. Cowling, The non-radial oscillations of polytropic stars, Mon. Not. Roy. Astron. Soc.101 (1941) 367. doi:10.1093/mnras/101.8.367

  52. [60]

    L¨ u, W.-M

    J.-L. L¨ u, W.-M. Suen, Determining the long living quasi-normal modes of relativistic stars, Chinese Physics B 20 (4) (2011) 040401. doi:10.1088/1674-1056/20/4/040401

  53. [61]

    J. P. Cox, Nonradial Oscillations of Stars: Theories and Observations, Annual Review of Astronomy and Astrophysics 14 (1) (1976) 247–273. doi:10.1146/annurev.aa.14.090176.001335

  54. [62]

    M. C. Rodriguez, I. F. Ranea-Sandoval, C. Chirenti, D. Radice, Three approaches for the classification of protoneutron star oscilla- tion modes, Monthly Notices of the Royal Astronomical Society (2023) stad1459doi:10.1093/mnras/stad1459. 24

  55. [63]

    J. B. Hartle, Slowly Rotating Relativistic Stars. I. Equations of Struc- ture, Astro. Phys. J. 150 (1967) 1005. doi:10.1086/149400

  56. [64]

    Pappas, T

    G. Pappas, T. A. Apostolatos, Revising the Multipole Moments of Nu- merical Spacetimes and its Consequences, Phys. Rev. Lett.108 (23) (2012) 231104. arXiv:1201.6067, doi:10.1103/PhysRevLett.108.231104

  57. [65]

    Stergioulas, J

    N. Stergioulas, J. L. Friedman, Comparing Models of Rapidly Rotating Relativistic Stars Constructed by Two Numerical Methods, Astro. Phys. J. 444 (1995) 306. arXiv:astro-ph/9411032, doi:10.1086/175605

  58. [66]

    Astrophys

    Nozawa, T., Stergioulas, N., Gourgoulhon, E., Eriguchi, Y., Construc- tion of highly accurate models of rotating neutron stars - comparison of three different numerical schemes, Astron. Astrophys. Suppl. Ser. 132 (3) (1998) 431–454. doi:10.1051/aas:1998304. URL https://doi.org...

  59. [67]

    Riahi, S

    R. Riahi, S. Z. Kalantari, J. A. Rueda, Universal relations for the keple- rian sequence of rotating neutron stars, Phys. Rev. D 99 (2019) 043004. doi:10.1103/PhysRevD.99.043004. URL https://link.aps.org/doi/10.1103/PhysRevD.99.043004

  60. [68]

    K. Yagi, N. Yunes, Binary Love relations, Classical and Quantum Gravity 33 (13) (2016) 13LT01. arXiv:1512.02639, doi:10.1088/0264- 9381/33/13/13LT01

  61. [69]

    H. O. Silva, N. Yunes, I-Love-Q to the extreme, Classical and Quan- tum Gravity 35 (1) (2018) 015005. arXiv:1710.00919, doi:10.1088/1361- 6382/aa995a

  62. [70]

    Marques, M

    M. Marques, M. Oertel, M. Hempel, J. Novak, New temperature de- pendent hyperonic equation of state: Application to rotating neutron star models and I -Q relations, Phys. Rev. C96 (4) (2017) 045806. arXiv:1706.02913, doi:10.1103/PhysRevC.96.045806

  63. [71]

    Baub¨ ock, E

    M. Baub¨ ock, E. Berti, D. Psaltis, F. ¨Ozel, Relations between Neutron- star Parameters in the Hartle-Thorne Approximation, Astro. Phys. J. 777 (1) (2013) 68. arXiv:1306.0569, doi:10.1088/0004-637X/777/1/68

  64. [72]

    Pappas, T

    G. Pappas, T. A. Apostolatos, Effectively Universal Behavior of Rotat- ing Neutron Stars in General Relativity Makes Them Even Simpler than 25 Their Newtonian Counterparts, Phys. Rev. Lett.112 (12) (2014) 121101. arXiv:1311.5508, doi:10.1103/PhysRevLett.112.121101

  65. [73]

    Riahi, S

    R. Riahi, S. Z. Kalantari, J. A. Rueda, Universal relations for the Ke- plerian sequence of rotating neutron stars, Phys. Rev. D99 (4) (2019) 043004. arXiv:1902.00349, doi:10.1103/PhysRevD.99.043004

  66. [74]

    Jiang, K

    N. Jiang, K. Yagi, Analytic I-Love-C relations for realistic neu- tron stars, Phys. Rev. D101 (12) (2020) 124006. arXiv:2003.10498, doi:10.1103/PhysRevD.101.124006

  67. [75]

    Nedora, S

    V. Nedora, S. Bernuzzi, D. Radice, B. Daszuta, A. Endrizzi, A. Perego, A. Prakash, M. Safarzadeh, F. Schianchi, D. Logoteta, Numerical Rel- ativity Simulations of the Neutron Star Merger GW170817: Long-term Remnant Evolutions, Winds, Remnant Disks, and Nucleosynthesis, As- tro...

  68. [984]

    arXiv:astro-ph/0411470, doi:10.1086/431543. 21

  69. [2390]

    doi:10.1103/PhysRevD.30.2379. 19

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