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Transport Properties of the MRI in Differentially Rotating Neutron Stars

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Pith's one-line read MRI turbulence in neutron stars mixes on a scale ten times smaller than subgrid models assume, so dimensional closures only work qualitatively.

desk verdict Useful coefficient measurements that challenge common GRLES closures, with the main caveat the authors already flag: the headline ratio may still be resolution-limited. read the letter →

arxiv 2607.24457 v1 pith:BSZZEKE6 submitted 2026-07-27 astro-ph.HE gr-qc

Harshraj Bandyopadhyay , Peter Hammond , David Radice This is my paper · ORCID
classification astro-ph.HEgr-qc
keywords magnetorotationalinstabilityneutronstarsGRMHDturbulenttransportmixinglengthmean-fielddynamolarge-eddysimulationdifferentialrotation
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

When a neutron star is spinning differentially, the magnetorotational instability drives turbulence that redistributes angular momentum and can decide whether the star collapses. Global simulations cannot resolve the tiny MRI wavelength, so large-eddy models insert effective transport coefficients chosen by dimensional analysis. This paper measures those coefficients directly in three-dimensional GRMHD runs of collapsing and non-collapsing stars. At saturation the mixing length tracks the MRI wavelength but sits an order of magnitude below the usual assumption that the two scales are comparable, and it shows almost no density dependence. The dynamo coefficient correlates only shallowly with Alfvén speed and both quantities fluctuate strongly in space and time. The practical claim is that dimensional closures can capture the qualitative effect of MRI turbulence, but quantitative predictions of collapse, jets, or ejecta require fully resolved GRMHD.

What carries the argument

Direct extraction of residual Maxwell stress and turbulent electromotive force from azimuthally averaged, fully resolved GRMHD snapshots, closed as a Smagorinsky-type eddy viscosity ν_T = ℓ_mix c_s and a mean-field α-dynamo coefficient; the measured ratio ℓ_mix/λ_MRI is the central diagnostic.

What would settle it

A higher-resolution suite of the same models in which the quality factor is substantially increased and the saturated value of ℓ_mix/λ_MRI is shown either to stay near 0.01–0.1 or to rise toward unity.

Watch

Extended reading notes

Core claim

At saturation, the effective mixing length of MRI-driven turbulence in differentially rotating neutron stars is largely independent of density and satisfies ℓ_mix ≈ (10^{-2}–10^{-1}) λ_MRI—roughly an order of magnitude below the common subgrid assumption ℓ_mix ∼ λ_MRI—while α_DYN correlates only shallowly with v_A; both coefficients are highly intermittent, so dimensional-analysis transport coefficients reproduce MRI effects only qualitatively and fully resolved GRMHD is required for quantitative predictions.

Load-bearing premise

That the measured saturated ratio of mixing length to MRI wavelength is a physical property of the turbulence rather than an artifact of the grid, even though the saturated MRI wavelength itself is only a few cells across.

Editorial extensions

If this is right

  • Subgrid models that set ℓ_mix ∼ λ_MRI systematically overestimate turbulent angular-momentum transport in neutron-star interiors.
  • Density-dependent mixing-length prescriptions used in many GR large-eddy simulations are not supported by the measured turbulence.
  • Collapse time, large-scale field growth, and outflow launching in merger remnants cannot be predicted quantitatively from dimensional closures alone.
  • The same order-of-magnitude offset and intermittency appear in both collapsing and long-lived models once MRI turbulence is established.

Reading between the lines

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

  • If the ratio remains small at higher resolution, calibrated LES for BNS remnants will need a reduced transport length rather than a simple rescaling of existing closures.
  • The absence of a clean density trend for ℓ_mix suggests that merger-remnant LES should treat the mixing length as a global fraction of the local driving scale, not a local function of ρ.
  • Intermittency of α_DYN implies that mean-field dynamo terms in long-term remnant evolutions may need stochastic or spatially fluctuating amplitudes.
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Editorial analysis

A structured set of objections, weighed in public.

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

Circularity Check

0 steps flagged · score 0.0 of 10

No circularity: transport coefficients are measured from resolved stresses/EMFs and compared to external dimensional-analysis benchmarks that the data then violate.

full rationale

The paper’s load-bearing results are direct extractions of α_vis, ν_T/ℓ_mix, and α_DYN from azimuthally averaged Maxwell stress and fluctuation EMF in fully evolved GRMHD runs (Eqs. 23, 25, 27), not quantities forced by a closure that is then re-read as a prediction. Dimensional-analysis expectations (ℓ_mix ∼ λ_MRI, α_DYN ∼ v_A) and the ℓ_mix(ρ) GRLES ansatz appear only as external comparison targets; the saturated data are reported to deviate from those targets by roughly an order of magnitude and to be density-independent for ℓ_mix. Citations to the group’s prior GRLES framework define what is being tested, not the measured values. Power-law fits (α_vis(ρ), v_Az(|α_DYN|)) are descriptive summaries of the same measurements, not fitted inputs recycled as predictions. Resolution and transferability concerns about ℓ_mix/λ_MRI are real scientific caveats but are not circularity. No self-definitional loop, uniqueness import, or ansatz-smuggling reduces the central claims to their inputs.

Assumptions & free parameters 4 free parameters · 7 assumptions · 0 invented entities

The central claim rests on standard ideal GRMHD plus several domain modeling choices that fix what ‘transport coefficient’ means and what scale is resolved. No new physical entities are postulated; the free choices are numerical/seed and closure assumptions used when reducing the turbulent field to scalar coefficients.

free parameters (4)
  • Initial vector-potential amplitude Ain and pressure cutoff Pcut = Model-dependent (e.g. Ain=4.57–28.98 in code units)
    Hand-chosen poloidal seed that sets initial |B| and thus initial Q_MRI and the early winding/MRI path; listed per model in Table II.
  • Differential-rotation length  = A/ϖ_e = 1 = 1
    Fixed j-constant steepness for all models following Duez et al.; controls shear reservoir that drives MRI.
  • Saturated-phase time windows for averaging = Model-dependent intervals marked in Figs. 6 and 14
    Windows (e.g. B1: 37.73–80.55 ms) are chosen by eye from coefficient plateaus; they define all reported saturated medians.
  • Density-bin edges [ρ_glob_min, ρ_glob_max] = 10 bins; ρ_min=1e-6, ρ_max=0.75 ρ_max,0
    Ten fixed log bins with ρ_glob_max=0.75 ρ_max,0 and ρ_glob_min=10^{-6} M_⊙^{-2} control how coefficients are aggregated versus density.
assumptions (7)
  • domain assumption Ideal GRMHD (perfect conductivity, no neutrinos, no resistivity) on a dynamical spacetime evolved with Z4c + constrained transport.
    Stated throughout §§II–III; excludes non-ideal effects known to matter in hot remnants.
  • domain assumption Γ=2 polytropic initial data and Γ-law evolution adequately represent the thermodynamics for transport-coefficient extraction.
    §III.A; authors note this is an idealization of finite-temperature merger EOS.
  • domain assumption j-constant rotation law is a sufficient proxy for post-merger differential rotation when measuring MRI transport.
    §III.A explicitly warns the profile differs from merger-calibrated laws.
  • domain assumption Azimuthal averages commute with covariant derivatives because non-axisymmetric metric structure is subdominant (axisymmetric background).
    §IID; required for residual-stress and EMF definitions.
  • domain assumption Turbulent Maxwell stress dominates Reynolds stress; residual stress may be closed with a relativistic eddy-viscosity (Smagorinsky-type) model using vturb=cs.
    §IID–IIE2; adopted as modeling assumption ‘not a measured property of these runs.’
  • domain assumption λ_MRI = 2π v_Az/|Ω| with Newtonian weak-field v_Az is an adequate order-of-magnitude proxy for the driving scale when forming ℓ_mix/λ_MRI.
    Eqs. (11),(26); used as the denominator of the headline ratio.
  • standard math Standard 3+1 GRMHD conservation laws, Maxwell equations, and Reynolds/Favre decompositions.
    §IIA–IIC; textbook structure underlying all diagnostics.

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Pith. "Pith review of Transport Properties of the MRI in Differentially Rotating Neutron Stars." pith.science (2026). https://pith.science/paper/BSZZEKE6

@misc{pith2026260724457,
  author       = {Pith},
  title        = {Pith review of: Transport Properties of the MRI in Differentially Rotating Neutron Stars},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/BSZZEKE6}},
  note         = {Machine review of arXiv:2607.24457}
}
abstract

We perform three-dimensional, high-resolution, general-relativistic magnetohydrodynamics (GRMHD) simulations of the magnetorotational instability (MRI) in differentially rotating neutron stars. We consider both high-mass models which collapse either promptly, or due to the outward transport of angular momentum removing rotational support, and lower-mass models, which remain stable even after solid-body rotation has been achieved. We measure effective transport coefficients of the resulting turbulent flow, shear-viscosity $\alpha_{\rm vis}$, mixing-length $\ell_{\rm mix}$, and mean-field dynamo $\alpha_{\rm DYN}$-parameter, and their correlations with mean-flow parameters, such as rest-mass density $\rho$, characteristic wavelength of the MRI $\lambda_{\rm MRI}$, and vertical Alfv\'en velocity $v_A$. At saturation, $\ell_{\rm mix}$ and $\alpha_{\rm DYN}$ correlate with $\lambda_{\rm MRI}$ and $v_A$ respectively, as expected from dimensional analysis. However, both quantities show deviations of roughly an order of magnitude from the values predicted on the basis of these correlations. They are also highly intermittent in space and time. The mixing length is found to be largely independent of density, calling into question the $\ell_{\rm mix}(\rho)$ ansatz used in many general-relativistic large-eddy simulations. Our results show that, while the effects of MRI-induced turbulence might be qualitatively reproduced by simulations that employ transport coefficients chosen using dimensional-analysis considerations, fully-resolved GRMHD simulations are needed to make quantitative predictions.

Figures

Figures reproduced from arXiv: 2607.24457 by the authors.

Figure 1
Figure 1. FIG. 1. Angle (Azimuthal) averaged angular velocity profile [PITH_FULL_IMAGE:figures/full_fig_p009_1.png] view at source ↗
Figure 2
Figure 2. FIG. 2. Evolution of the maximum toroidal and poloidal magnetic-field components (in log scale). The dashed black line shows [PITH_FULL_IMAGE:figures/full_fig_p011_2.png] view at source ↗
Figure 3
Figure 3. FIG. 3. Total magnetic field [PITH_FULL_IMAGE:figures/full_fig_p012_3.png] view at source ↗
Figures from the paper (12 more)
Figure 4
Figure 4. Figure 4: FIG. 4. Dynamo coefficient [PITH_FULL_IMAGE:figures/full_fig_p013_4.png]
Figure 5
Figure 5. Figure 5: FIG. 5. Turbulent mixing length [PITH_FULL_IMAGE:figures/full_fig_p013_5.png]
Figure 6
Figure 6. Figure 6: FIG. 6. Time evolution of four transport coefficients for [PITH_FULL_IMAGE:figures/full_fig_p014_6.png]
Figure 7
Figure 7. Figure 7: FIG. 7. Mixing length [PITH_FULL_IMAGE:figures/full_fig_p015_7.png]
Figure 8
Figure 8. Figure 8: FIG. 8. Effective viscosity parameter [PITH_FULL_IMAGE:figures/full_fig_p015_8.png]
Figure 9
Figure 9. Figure 9: FIG. 9. Mixing length [PITH_FULL_IMAGE:figures/full_fig_p016_9.png]
Figure 10
Figure 10. Figure 10: FIG. 10 [PITH_FULL_IMAGE:figures/full_fig_p017_10.png]
Figure 11
Figure 11. Figure 11: FIG. 11. The dynamo coefficient [PITH_FULL_IMAGE:figures/full_fig_p017_11.png]
Figure 13
Figure 13. Figure 13: FIG. 13. Mixing length [PITH_FULL_IMAGE:figures/full_fig_p018_13.png]
Figure 14
Figure 14. Figure 14: FIG. 14. Time evolution of the four transport coefficients ( [PITH_FULL_IMAGE:figures/full_fig_p019_14.png]
Figure 15
Figure 15. Figure 15: FIG. 15 [PITH_FULL_IMAGE:figures/full_fig_p020_15.png]
Figure 16
Figure 16. Figure 16: FIG. 16. Similar to Fig. 12, this is the vertical Alfvén speed [PITH_FULL_IMAGE:figures/full_fig_p020_16.png]

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Works this paper leans on

101 extracted references · 2 canonical work pages

  1. [1]

    This ties the turbulent transport directly to the viscous-disc framework, in whichα vis is the single free parameter [19, 52, 68]

    Shakura-Sunyaev normalizationα vis Normalizing the mean mixed Maxwell stress by the pressure gives the relativistic analogue of the classical accretion-disc parameter [50], αvis = −b ϖbϕ vol P vol ,(23) where both averages are volume-weighted. This ties the turbulent transport directly to the viscous-disc framework, in whichα vis is the single free parame...

  2. [2]

    Let Di be the covariant derivative ofγij, with connection Γkij = 1 2 γkl(∂iγjl + ∂jγil −∂ lγij)

    Turbulent viscosityν T and mixing lengthℓmix We close the trace-free residual stress with the rela- tivistic eddy-viscosity (Smagorinsky-type) model [53, 87]. Let Di be the covariant derivative ofγij, with connection Γkij = 1 2 γkl(∂iγjl + ∂jγil −∂ lγij). The trace-free rate of strain of the mean Eulerian velocity is Σij = 1 2 (Divj +D jvi)− 1 3 Dkvk γij....

  3. [3]

    j-constant

    Mean-field dynamo coefficientα DYN We keep only the leadingα-term in Eq.(20) and project onto the mean field. This gives the least-squares estimate αDYN = ⟨Ei⟩vol ⟨Bi⟩vol ⟨Bi⟩vol ⟨Bi⟩vol .(27) On the grid, we build the covariant turbulent EMF from the Eulerian velocityvi = V i/W (Eq. (2)) and the fluc- tuations δQ = Q− ⟨Q⟩vol. It is Ei = ϵijk δv jδB k, wi...

  4. [4]

    B. P. Abbottet al.(LIGO Scientific Collaboration and Virgo Collaboration), GW170817: Observation of gravi- tational waves from a binary neutron star inspiral, Phys. Rev. Lett.119, 161101 (2017), arXiv:1710.05832 [gr-qc]

    arXiv 2017

  5. [5]

    B. P. Abbottet al.(LIGO Scientific Collaboration and Virgo Collaboration and Fermi GBM and INTEGRAL), Gravitational waves and gamma-rays from a binary neu- tron star merger: GW170817 and GRB 170817A, Astro- 19 FIG. 14. Time evolution of the four transport coefficients (αvis, λMRI, ℓmix/λMRI, and |αDYN|/vz A rows) for A1, B2, and A2 (columns), with curves ...

    arXiv 2017

  6. [6]

    Kasen, B

    D. Kasen, B. Metzger, J. Barnes, E. Quataert, and E. Ramírez-Ruiz, Origin of the heavy elements in binary neutron-star mergers from a gravitational-wave event, Nature551, 80 (2017), arXiv:1710.05463 [astro-ph.HE]

    arXiv 2017

  7. [7]

    B. D. Metzger, Kilonovae, Living Rev. Relativ.23, 1 (2020), arXiv:1910.01617 [astro-ph.HE]

    arXiv 2020

  8. [8]

    Shibata and K

    M. Shibata and K. Ury¯ u, Simulation of merging binary neutron stars in full general relativity:Γ = 2case, Phys. Rev. D61, 064001 (2000), arXiv:gr-qc/9911058

    arXiv 2000

Show all 101 references
  1. [9]

    T. W. Baumgarte, S. L. Shapiro, and M. Shibata, On the maximum mass of differentially rotating neutron stars, Astrophys. J. Lett.528, L29 (2000), arXiv:astro- ph/9910565

    2000

  2. [10]

    Janka, K

    H.-T. Janka, K. Langanke, A. Marek, G. Martínez-Pinedo, and B. Müller, Theory of core-collapse supernovae, Phys. Rep.442, 38 (2007), arXiv:astro-ph/0612072

    2007 arXiv

  3. [11]

    Rembiasz, J

    T. Rembiasz, J. Guilet, M. Obergaulinger, P. Cerdá- Durán, M. Aloy, and E. Müller, On the maximum mag- netic field amplification by the magnetorotational insta- bility in core-collapse supernovae, Monthly Notices of the Royal Astronomical Society460, 3316 (2016)

    2016

  4. [12]

    M.D.Duez, Y.T.Liu, S.L.Shapiro, M.Shibata,andB.C. 20 FIG. 15. αvis vs ρ plot similar to Fig. 8, forA2 (left) and B2 (right). B2 (15.27 − 32.07 ms) reproduces the same monotonic density dependence, αvis ∝ρ −0.41, supporting the generality of the trend across models. However,A2 ...

    2006 arXiv

  5. [13]

    Kiuchi, P

    K. Kiuchi, P. Cerdá-Durán, K. Kyutoku, Y. Sekiguchi, and M. Shibata, Efficient magnetic-field amplification due to the Kelvin–Helmholtz instability in binary neu- tron star mergers, Phys. Rev. D92, 124034 (2015), arXiv:1509.09205 [astro-ph.HE]

    2015 arXiv

  6. [14]

    Kiuchi, K

    K. Kiuchi, K. Kyutoku, Y. Sekiguchi, and M. Shibata, Global simulations of strongly magnetized remnant mas- sive neutron stars formed in binary neutron star mergers, Phys. Rev. D97, 124039 (2018), arXiv:1710.01311 [astro- ph.HE]

    2018 arXiv

  7. [15]

    Kiuchi, A

    K. Kiuchi, A. Reboul-Salze, M. Shibata, and Y. Sekiguchi, A large-scale magnetic field produced by a solar-like dy- namo in binary neutron star mergers, Nat. Astron.8, 298 (2024), arXiv:2306.15721 [astro-ph.HE]

    2024 arXiv

  8. [16]

    Kiuchi, A

    K. Kiuchi, A. Reboul-Salze, Y. Sekiguchi, and M. Shibata, A magnetar formation in binary neutron star merger (2026), arXiv:2606.11299 [astro-ph.HE]

    2026 arXiv

  9. [17]

    E. R. Most and E. Quataert, Flares, jets, and quasiperi- odic outbursts from neutron star merger remnants, Astro- phys. J. Lett.947, L15 (2023), arXiv:2303.08062 [astro- ph.HE]

    2023 arXiv

  10. [18]

    Combi and D

    L. Combi and D. M. Siegel, Jets from neutron-star merger remnants and massive blue kilonovae, Phys. Rev. Lett. 131, 231402 (2023)

    2023

  11. [19]

    magnetars

    C. Musolino, L. Rezzolla, and E. R. Most, On the impact of neutrinos on the launching of relativistic jets from “magnetars” produced in neutron star mergers, Astrophys. J. Lett.984, L61 (2025), arXiv:2410.06253 [astro-ph.HE]

    2025 arXiv

  12. [20]

    S. A. Balbus and J. F. Hawley, A powerful local shear 21 instability in weakly magnetized disks. i. linear analysis, Astrophys. J.376, 214 (1991)

    1991

  13. [21]

    S. A. Balbus and J. F. Hawley, Instability, turbulence, and enhanced transport in accretion disks, Rev. Mod. Phys.70, 1 (1998)

    1998

  14. [22]

    S. A. Balbus, Enhanced angular momentum transport in accretion disks, Annu. Rev. Astron. Astrophys.41, 555 (2003), arXiv:astro-ph/0306208

    2003 arXiv

  15. [23]

    Akiyama, J

    S. Akiyama, J. C. Wheeler, D. L. Meier, and I. Lichten- stadt, The magnetorotational instability in core-collapse supernova explosions, Astrophys. J.584, 954 (2003), arXiv:astro-ph/0208128

    2003 arXiv

  16. [24]

    Obergaulinger, P

    M. Obergaulinger, P. Cerdá-Durán, E. Müller, and M. A. Aloy, Semi-global simulations of the magneto-rotational instability in core collapse supernovae, Astron. Astrophys. 498, 241 (2009), arXiv:0811.1652 [astro-ph]

    2009 arXiv

  17. [25]

    Mösta, C

    P. Mösta, C. D. Ott, D. Radice, L. F. Roberts, E. Schnet- ter, and R. Haas, A large-scale dynamo and magneto- turbulence in rapidly rotating core-collapse supernovae, Nature528, 376 (2015)

    2015

  18. [26]

    Reboul-Salze, J

    A. Reboul-Salze, J. Guilet, R. Raynaud, and M. Bugli, A global model of the magnetorotational instability in protoneutron stars, Astron. Astrophys.645, A109 (2021), arXiv:2005.03567 [astro-ph.HE]

    2021 arXiv

  19. [27]

    Raynaud, J

    R. Raynaud, J. Guilet, H.-T. Janka, and T. Gastine, Mag- netar formation through a convective dynamo in protoneu- tron stars, Sci. Adv.6, eaay2732 (2020), arXiv:2003.06662 [astro-ph.HE]

    2020 arXiv

  20. [28]

    T. A. Thompson, E. Quataert, and A. Burrows, Viscosity and rotation in core-collapse supernovae, Astrophys. J. 620, 861 (2005), arXiv:astro-ph/0403224

    2005 arXiv

  21. [29]

    Burrows, L

    A. Burrows, L. Dessart, E. Livne, C. D. Ott, and J. Mur- phy, Simulations of magnetically driven supernova and hypernova explosions in the context of rapid rotation, Astrophys. J.664, 416 (2007), arXiv:astro-ph/0702539

    2007 arXiv

  22. [30]

    M. A. Aloy and M. Obergaulinger, Relativistic outflows in gamma-ray bursts, inRevista Mexicana de Astronomía y Astrofísica Serie de Conferencias, Vol. 30 (2007) pp. 96–103

    2007

  23. [31]

    Bugli, J

    M. Bugli, J. Guilet, M. Obergaulinger, P. Cerdá-Durán, and M. A. Aloy, The impact of non-dipolar magnetic fields in core-collapse supernovae, Mon. Not. R. Astron. Soc. 492, 58 (2020), arXiv:1909.02824 [astro-ph.HE]

    2020 arXiv

  24. [32]

    Bugli, J

    M. Bugli, J. Guilet, and M. Obergaulinger, Three- dimensional core-collapse supernovae with complex mag- netic structures - I. explosion dynamics, Mon. Not. R. Astron. Soc.507, 443 (2021)

    2021

  25. [33]

    M. A. Aloy and M. Obergaulinger, Magnetorotational core collapse of possible gamma-ray burst progenitors - II. formation of protomagnetars and collapsars, Mon. Not. R. Astron. Soc.500, 4365 (2021)

    2021

  26. [34]

    Powell, B

    J. Powell, B. Müller, D. R. Aguilera-Dena, and A. Heger, Three dimensional magnetorotational core-collapse super- nova explosions of a 39 solar mass progenitor star, Mon. Not. R. Astron. Soc.522, 6070 (2023)

    2023

  27. [35]

    Giacomazzo, L

    B. Giacomazzo, L. Rezzolla, and N. Stergioulas, Collapse of differentially rotating neutron stars and cosmic censor- ship, Phys. Rev. D84, 024022 (2011), arXiv:1105.0122 [gr-qc]

    2011 arXiv

  28. [36]

    Palenzuela, R

    C. Palenzuela, R. Aguilera-Miret, F. Carrasco, R. Ciolfi, J. V. Kalinani, W. Kastaun, B. Miñano, and D. Viganò, Turbulent magnetic field amplification in binary neu- tron star mergers, Phys. Rev. D106, 023013 (2022), arXiv:2112.08413 [gr-qc]

    2022 arXiv

  29. [37]

    Aguilera-Miret, C

    R. Aguilera-Miret, C. Palenzuela, F. Carrasco, and D. Vi- ganò, Role of turbulence and winding in the development of large-scale, strong magnetic fields in long-lived rem- nants of binary neutron star mergers, Phys. Rev. D108, 103001 (2023), arXiv:2307.04837 [astro-ph.HE]

    2023 arXiv

  30. [38]

    Aguilera-Miret, J.-E

    R. Aguilera-Miret, J.-E. Christian, S. Rosswog, and C. Palenzuela, Robustness of magnetic field amplifica- tion in neutron star mergers, Mon. Not. R. Astron. Soc. 542, 3067 (2025), arXiv:2504.10604 [astro-ph.HE]

    2025

  31. [39]

    E. M. Gutiérrez, D. Radice, J. Fields, and J. M. Stone, Turbulent dynamo action in binary neutron star mergers (2026), arXiv:2601.20953 [astro-ph.HE]

    2026

  32. [40]

    Baiotti, B

    L. Baiotti, B. Giacomazzo, and L. Rezzolla, Accurate evolutions of inspiralling neutron-star binaries: Prompt and delayed collapse to a black hole, Phys. Rev. D78, 084033 (2008), arXiv:0804.0594 [gr-qc]

    2008 arXiv

  33. [41]

    Shibata, S

    M. Shibata, S. Fujibayashi, and Y. Sekiguchi, Long-term evolution of a merger-remnant neutron star in general relativistic magnetohydrodynamics: Effect of magnetic winding, Phys. Rev. D103, 043022 (2021)

    2021

  34. [42]

    D. M. Siegel, R. Ciolfi, A. I. Harte, and L. Rezzolla, Magnetorotational instability in relativistic hypermas- sive neutron stars, Phys. Rev. D87, 121302 (2013), arXiv:1302.4368 [gr-qc]

    2013 arXiv

  35. [43]

    Kiuchi, S

    K. Kiuchi, S. Fujibayashi, K. Hayashi, K. Kyutoku, Y. Sekiguchi, and M. Shibata, Self-consistent picture of the mass ejection from a one second long binary neutron star merger leaving a short-lived remnant in a general-relativistic neutrino-radiation magnetohydrody- namic simu...

    2023 arXiv

  36. [44]

    Eichler, M

    D. Eichler, M. Livio, T. Piran, and D. N. Schramm, Nucleosynthesis, neutrino bursts and gamma-rays from coalescing neutron stars, Nature340, 126 (1989)

    1989

  37. [45]

    Narayan, B

    R. Narayan, B. Paczyński, and T. Piran, Gamma-ray bursts as the death throes of massive binary stars, Astro- phys. J. Lett.395, L83 (1992)

    1992

  38. [46]

    Piran, The physics of gamma-ray bursts, Rev

    T. Piran, The physics of gamma-ray bursts, Rev. Mod. Phys.76, 1143 (2004), arXiv:astro-ph/0405503

    2004 arXiv

  39. [47]

    Kumar and B

    P. Kumar and B. Zhang, The physics of gamma-ray bursts and relativistic jets, Phys. Rep.561, 1 (2015), arXiv:1410.0679 [astro-ph.HE]

    2015 arXiv

  40. [48]

    L. Sun, M. Ruiz, S. L. Shapiro, and A. Tsokaros, Jet launching from binary neutron star mergers: Incorporat- ing neutrino transport and magnetic fields, Phys. Rev. D 105, 104028 (2022), arXiv:2202.12901 [astro-ph.HE]

    2022 arXiv

  41. [49]

    Gottliebet al., Large-scale evolution of seconds-long relativistic jets from black hole-neutron star mergers, As- trophys

    O. Gottliebet al., Large-scale evolution of seconds-long relativistic jets from black hole-neutron star mergers, As- trophys. J. Lett.954, L21 (2023)

    2023

  42. [50]

    Bamber, A

    J. Bamber, A. Tsokaros, M. Ruiz, and S. L. Shapiro, Jetlike structures in low-mass binary neutron star merger remnants, Phys. Rev. D110, 024046 (2024), arXiv:2405.03705 [astro-ph.HE]

    2024 arXiv

  43. [51]

    Radice, General-relativistic large-eddy simulations of binary neutron star mergers, Astrophys

    D. Radice, General-relativistic large-eddy simulations of binary neutron star mergers, Astrophys. J. Lett.838, L2 (2017), arXiv:1703.02046 [astro-ph.HE]

    2017 arXiv

  44. [52]

    Carrasco, D

    F. Carrasco, D. Viganò, and C. Palenzuela, Gradi- ent subgrid-scale model for relativistic MHD large- eddy simulations, Phys. Rev. D101, 063003 (2020), arXiv:1908.01419 [physics.comp-ph]

    2020 arXiv

  45. [53]

    N. I. Shakura and R. A. Sunyaev, Black holes in binary systems. observational appearance, Astron. Astrophys. 24, 337 (1973)

    1973

  46. [54]

    M. E. Pessah, C.-K. Chan, and D. Psaltis, The funda- 22 mental difference between shearα-viscosity and turbulent magnetorotational stresses, Mon. Not. R. Astron. Soc. 383, 683 (2008), arXiv:astro-ph/0612404

    2008 arXiv

  47. [55]

    R. F. Penna, A. Sądowski, A. K. Kulkarni, and R. Narayan, The Shakura–Sunyaev viscosity prescription with variable α(r), Mon. Not. R. Astron. Soc.428, 2255 (2013), arXiv:1211.0526 [astro-ph.HE]

    2013 arXiv

  48. [56]

    Radice, Binary neutron star merger simulations with a calibrated turbulence model, Symmetry12, 1249 (2020), arXiv:2005.09002 [astro-ph.HE]

    D. Radice, Binary neutron star merger simulations with a calibrated turbulence model, Symmetry12, 1249 (2020), arXiv:2005.09002 [astro-ph.HE]

    2020 arXiv

  49. [57]

    Radice and S

    D. Radice and S. Bernuzzi, Ab-initio general-relativistic neutrino-radiation hydrodynamics simulations of long- lived neutron star merger remnants to neutrino cooling timescales,Astrophys.J.959,46(2023),arXiv:2306.13709 [astro-ph.HE]

    2023

  50. [58]

    Hayashi, S

    K. Hayashi, S. Fujibayashi, K. Kawaguchi, K. Kiuchi, K.Kyutoku,andM.Shibata,General-relativisticneutrino- radiation magnetohydrodynamic simulation of seconds- long black hole-neutron star mergers, Phys. Rev. D106, 023008 (2022)

    2022

  51. [59]

    Radice and I

    D. Radice and I. Hawke, Turbulence modelling in neutron star merger simulations, Living Rev. Comput. Astrophys. 10, 1 (2024), arXiv:2402.03224 [astro-ph.HE]

    2024 arXiv

  52. [60]

    W. Cook, B. Daszuta, J. Fields, P. Hammond, S. Albanesi, F. Zappa, S. Bernuzzi, and D. Radice, GR-Athena++: General-relativistic magnetohydrodynamics simulations of neutron star spacetimes, Astrophys. J. Suppl. Ser.277, 3 (2025), arXiv:2311.04989 [gr-qc]

    2025 arXiv

  53. [61]

    Daszuta, F

    B. Daszuta, F. Zappa, W. Cook, D. Radice, S. Bernuzzi, and V. Morozova, GR-Athena++: Puncture evolutions on vertex-centered oct-tree adaptive mesh refinement, Astrophys. J. Suppl. Ser.257, 25 (2021), arXiv:2101.08289 [gr-qc]

    2021 arXiv

  54. [62]

    Daszuta and W

    B. Daszuta and W. Cook, Gr-athena++: magnetohydro- dynamical evolution with dynamical space-time (2024), arXiv:2406.05126 [gr-qc]

    2024 arXiv

  55. [63]

    Daszuta, S

    B. Daszuta, S. Bernuzzi, M. Jacobi, E. M. Gutiérrez, P. Hammond, W. Cook, and D. Radice, GR-Athena++: Binary neutron star merger simulations with neutrino transport (2026), arXiv:2602.18290 [gr-qc]

    2026

  56. [64]

    K. Kiuchi, General relativistic magnetohydrodynamics simulations for binary neutron star mergers, arXiv e- prints 10.48550/arXiv.2405.10081 (2024), published 2025 in: New Frontiers in GRMHD Simulations, Springer, DOI:10.1007/978-981-97-8522-3_16, arXiv:2405.10081 [astro-ph.HE]

    2024 doi arXiv

  57. [65]

    Mizuno and L

    Y. Mizuno and L. Rezzolla, General-relativistic magne- tohydrodynamic equations: The bare essential, inNew Frontiers in GRMHD Simulations(Springer Nature Sin- gapore, 2025) pp. 3–28, arXiv:2404.13824 [astro-ph.HE]

    2025 arXiv

  58. [66]

    T. W. Baumgarte and S. L. Shapiro,Numerical Relativity: Solving Einstein’s Equations on the Computer(Cambridge University Press, 2010)

    2010

  59. [67]

    Rezzolla and O

    L. Rezzolla and O. Zanotti,Relativistic Hydrodynamics (Oxford University Press, Oxford, 2013)

    2013

  60. [68]

    J. M. Bardeen, W. H. Press, and S. A. Teukolsky, Ro- tating black holes: Locally nonrotating frames, energy extraction, and scalar synchrotron radiation, Astrophys. J.178, 347 (1972)

    1972

  61. [69]

    W. Cook, R. K. Joshi, S. Bernuzzi, B. Haskell, and J. Fields, Turbulence in magnetized neutron stars, Mon. Not. R. Astron. Soc.547, stag136 (2026), arXiv:2506.08037 [astro-ph.HE]

    2026 arXiv

  62. [70]

    Paschalidis and N

    V. Paschalidis and N. Stergioulas, Rotating stars in rela- tivity, Living Rev. Relativ.20, 7 (2017), arXiv:1612.03050 [astro-ph.HE]

    2017 arXiv

  63. [71]

    Frank, A

    J. Frank, A. King, and D. J. Raine,Accretion Power in Astrophysics, 3rd ed. (Cambridge University Press, Cambridge, 2002)

    2002

  64. [72]

    M. D. Duez, Y. T. Liu, S. L. Shapiro, and B. C. Stephens, Relativistic magnetohydrodynamics in dynamical space- times: Numerical methods and tests, Phys. Rev. D72, 024028 (2005), arXiv:astro-ph/0503420

    2005 arXiv

  65. [73]

    S. C. Noble, J. H. Krolik, and J. F. Hawley, Depen- dence of inner accretion disk stress on parameters: The Schwarzschild case, Astrophys. J.711, 959 (2010), arXiv:1001.4809 [astro-ph.HE]

    2010 arXiv

  66. [74]

    J. F. Hawley, X. Guan, and J. H. Krolik, Assessing quan- titative results in accretion simulations: From local to global, Astrophys. J.738, 84 (2011), arXiv:1103.5987 [astro-ph.HE]

    2011 arXiv

  67. [75]

    J. F. Hawley, S. A. Richers, X. Guan, and J. H. Krolik, Testing convergence for global accretion disks, Astrophys. J.772, 102 (2013), arXiv:1306.0243 [astro-ph.HE]

    2013 arXiv

  68. [76]

    Rembiasz, M

    T. Rembiasz, M. Obergaulinger, P. Cerdá-Durán, E. Müller, and M. A. Aloy, Termination of the magne- torotational instability via parasitic instabilities in core- collapse supernovae, Mon. Not. R. Astron. Soc.456, 3782 (2016), arXiv:1508.04799 [astro-ph.SR]

    2016 arXiv

  69. [77]

    Miravet-Tenés, M

    M. Miravet-Tenés, M. Obergaulinger, P. Cerdá-Durán, J. A. Font, and M. Ruiz, Subgrid modelling of MRI-driven turbulence in differentially rotating neutron stars, Mon. Not. R. Astron. Soc.545, 10.1093/mnras/staf2081 (2026), arXiv:2509.07081 [astro-ph.HE]

    2026

  70. [78]

    Sagaut and C

    P. Sagaut and C. Cambon,Homogeneous Turbulence Dy- namics, 2nd ed. (Springer International Publishing, Cham, 2018)

    2018

  71. [79]

    Viganò, R

    D. Viganò, R. Aguilera-Miret, F. Carrasco, B. Miñano, and C. Palenzuela, GRMHD large-eddy simulations with gradient subgrid-scale model, Phys. Rev. D101, 123019 (2020), arXiv:2004.00870 [gr-qc]

    2020 arXiv

  72. [80]

    Aguilera-Miret, D

    R. Aguilera-Miret, D. Viganò, and C. Palenzuela, Uni- versality of the turbulent magnetic field in hypermassive neutron stars produced by binary mergers, Astrophys. J. Lett.926, L31 (2022), arXiv:2112.08406 [gr-qc]

    2022 arXiv

  73. [81]

    M. R. Izquierdo, M. Bezares, S. Liebling, and C. Palen- zuela, Large eddy simulations of magnetized mergers of black holes and neutron stars, Phys. Rev. D110, 10.1103/PhysRevD.110.083017 (2024), arXiv:2403.09770 [astro-ph.HE]

    2024 arXiv

  74. [82]

    Shibata, S

    M. Shibata, S. Fujibayashi, and Y. Sekiguchi, Long-term evolution of neutron-star merger remnants in general relativistic resistive magnetohydrodynamics with a mean- field dynamo term, Phys. Rev. D104, 063026 (2021), arXiv:2109.08732 [astro-ph.HE]

    2021 arXiv

  75. [83]

    S. B. Pope,Turbulent Flows(Cambridge University Press, Cambridge, 2000)

    2000

  76. [84]

    Kato and J

    S. Kato and J. Fukue,Fundamentals of astrophysical fluid dynamics: Hydrodynamics, magnetohydrodynamics, and radiation hydrodynamics(Springer, 2020)

    2020

  77. [85]

    Prandtl,Report on Investigation of Developed Turbu- lence, Tech

    L. Prandtl,Report on Investigation of Developed Turbu- lence, Tech. Rep. NACA-TM-1231 (National Advisory Committee for Aeronautics, 1949) translated from the original German article published in 1925

    1949

  78. [86]

    Brandenburg and K

    A. Brandenburg and K. Subramanian, Astrophysical mag- netic fields and nonlinear dynamo theory, Phys. Rep.417, 1 (2005), arXiv:astro-ph/0405052

    2005 arXiv

  79. [87]

    H. K. Moffatt,Magnetic Field Generation in Electrically 23 Conducting Fluids(Cambridge University Press, Cam- bridge, 1978)

    1978

  80. [88]

    Krause and K.-H

    F. Krause and K.-H. Rädler,Mean-Field Magnetohydro- dynamics and Dynamo Theory(Pergamon Press, Oxford, 1980)

    1980

  81. [89]

    E. R. Most, Impact of a mean field dynamo on neutron star mergers leading to magnetar remnants, Phys. Rev. D108, 123012 (2023), arXiv:2311.03333 [astro-ph.HE]

    2023 arXiv

  82. [90]

    Smagorinsky, General circulation experiments with the primitive equations

    J. Smagorinsky, General circulation experiments with the primitive equations. i. the basic experiment, Mon. Weather Rev.91, 99 (1963)

    1963

  83. [91]

    Hanauske, K

    M. Hanauske, K. Takami, L. Bovard, L. Rezzolla, J. A. Font, F. Galeazzi, and H. Stöcker, Rotational properties of hypermassive neutron stars from binary mergers, Physical Review D96, 10.1103/physrevd.96.043004 (2017)

    2017 doi

  84. [92]

    Ury¯ u, A

    K. Ury¯ u, A. Tsokaros, L. Baiotti, F. Galeazzi, K. Taniguchi, and S. Yoshida, Modeling differential rota- tions of compact stars in equilibriums, Physical Review D96, 10.1103/physrevd.96.103011 (2017)

    2017 doi

  85. [93]

    Tsokaros, J

    A. Tsokaros, J. Bamber, M. Ruiz, and S. L. Shapiro, Masking the equation-of-state effects in binary neu- tron star mergers, Phys. Rev. Lett.134, 121401 (2025), arXiv:2411.00939 [gr-qc]

    2025 arXiv

  86. [94]

    C. R. Evans and J. F. Hawley, Simulation of magneto- hydrodynamic flows: A Constrained transport method, Astrophys. J.332, 659 (1988)

    1988

  87. [95]

    C.J.White, J.M.Stone,andC.F.Gammie,AnExtension of the Athena++ Code Framework for GRMHD Based on Advanced Riemann Solvers and Staggered-Mesh Con- strained Transport, Astrophys. J. Suppl.225, 22 (2016), arXiv:1511.00943 [astro-ph.HE]

    2016 arXiv

  88. [96]

    D. S. Balsara and D. S. Spicer, A staggered mesh algo- rithm using high order godunov fluxes to ensure solenoidal magnetic fields in magnetohydrodynamic simulations, Journal of Computational Physics153, 671 (1999)

    1999

  89. [97]

    Giacomazzo and L

    B. Giacomazzo and L. Rezzolla, WhiskyMHD: A New numerical code for general relativistic magnetohydrody- namics, Class. Quant. Grav.24, S235 (2007), arXiv:gr- qc/0701109

    2007

  90. [98]

    Shibata, K

    M. Shibata, K. Kiuchi, and Y. Sekiguchi, General rel- ativistic viscous hydrodynamics of differentially rotat- ing neutron stars, Phys. Rev. D95, 083005 (2017), arXiv:1703.10303 [astro-ph.HE]

    2017 arXiv

  91. [99]

    Aguilera-Miret, C

    R. Aguilera-Miret, C. Palenzuela, F. Carrasco, S. Ross- wog, and D. Viganò, Delayed jet launching in binary neutron star mergers with realistic initial magnetic fields, Phys. Rev. D110, 083014 (2024), arXiv:2407.20335 [astro- ph.HE]

    2024 arXiv

  92. [100]

    Bamber, A

    J. Bamber, A. Tsokaros, M. Ruiz, and S. L. Shapiro, Postmerger multimessenger analysis of binary neutron stars: Effect of the magnetic field strength and topology, Phys. Rev. D111, 044038 (2025)

    2025

  93. [101]

    Rainho, J

    I. Rainho, J. Bamber, D. Guerra, M. Miravet-Tenés, M. Ruiz, A. Tsokaros, and S. L. Shapiro, Impact of mag- netic field topology on electromagnetic and gravitational waves from binary neutron star merger remnants (2025), arXiv:2510.17511 [astro-ph.HE]

    2025

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