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Predicting the outcome of collisional neutrino flavor conversion

T0 review · 3 major / 5 minor · reviewed 2026-08-07 · deepseek-v4-flash

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Pith's one-line read Collisions drive neutrino flavor to a predictable quantum equilibrium

desk verdict First closed-form prediction for CFI saturation is a useful step, but the load-bearing edge-of-instability rule is an unproven ansatz inferred from the same two simulations it validates. read the letter →

arxiv 2505.16961 v3 pith:G4DVPUYY submitted 2025-05-22 hep-ph astro-ph.HE

Julien Froustey This is my paper
classification hep-phastro-ph.HE
keywords collisionalflavorinstabilityquantumkineticequationsneutrinoconversionasymptoticstatepredictionneutronstarmergerneutrinoscoherencerelaxation-timeapproximationmarginalstability
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

Collisional neutrino flavor instabilities, driven by different reaction rates for neutrinos and antineutrinos, are expected in supernovae and neutron star mergers, but their nonlinear end state has so far resisted analytical description. This paper claims that for a homogeneous, isotropic, two-flavor, single-energy system, the late-time state is determined by two conditions alone: the flavor-diagonal densities are steady, and the configuration sits exactly at the edge of collisional instability. From those conditions the author derives explicit formulas for the asymptotic densities and for the nonzero flavor coherence, and shows that they match numerical solutions for two points in a neutron star merger simulation. This matters because it supplies the missing subgrid input for including collisional flavor conversion in large-scale simulations, and because it predicts a 'quantum' equilibrium rather than the flavor equipartition found in earlier treatments.

What carries the argument

The central object is the pair of collective eigenmodes of the linearized quantum kinetic equations, labeled the 'minus' and 'plus' modes, whose instantaneous growth rates are given by Eq. (7) in terms of the neutrino-antineutrino density asymmetry and the average collision rates. The derivation uses the steady-state conditions on the trace and on the electron-flavor difference, together with the requirement that the final configuration saturate the relevant instability, $\mathrm{Im}\,\Omega^{(\infty)} = 0$. The eigenvector structure does the remaining work: for the minus mode the coherence ratio equals the density asymmetry ratio, and for the plus mode the two coherences are equal, which makes the algebraic system closed and yields the coherence magnitude once the diagonal densities are known.

What would settle it

Solve the full quantum kinetic equations for a multienergy or weakly inhomogeneous version of the two merger points, or for a point where $\kappa_x$ is not much smaller than $\kappa_e$, and check whether the late-time diagonal densities and coherence agree with Eqs. (8)--(12) and (17); if the system does not settle at $\mathrm{Im}\,\Omega=0$ with constant densities, or if the outcome depends on the seed amplitude, the prediction fails.

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Extended reading notes

Core claim

The paper's core claim is that the saturated state of a collisional flavor instability is a 'quantum' equilibrium: the flavor-diagonal densities reach a steady value while a nonzero flavor coherence persists, and the system is parked exactly at the boundary where the relevant collective mode has zero growth rate, $\mathrm{Im}\,\Omega = 0$. In the minus-branch case this threshold condition is $\Gamma [N_{ee}^{(\infty)} - N_{xx}^{(\infty)}] = \bar{\Gamma} [N_{\bar{e}\bar{e}}^{(\infty)} - N_{\bar{x}\bar{x}}^{(\infty)}]$, with the plus branch obtained by exchanging barred and unbarred asymmetries; combined with the steady-state conditions this yields Eqs. (8)--(12) for the asymptotic diagonal densities. The residual coherence is given by Eq. (17), $R^{(\infty)} = \sqrt{ - \kappa_e (\kappa_e+\kappa_x)^{-1} [N_{ee}^{(\infty)} - N_{ee}^{(\mathrm{cl})}][N_{ee}^{(\infty)} - N_{xx}^{(\infty)}] }$, while the ratio of neutrino to antineutrino coherence remains fixed to the unstable eigenvector on both branches. The author further shows that a collision term acting only on flavor coherence, as in earlier studies, removes the repopulation of $\nu_e$ and $\bar{\nu}_e$ toward their classical values and therefore predicts equipartition rather than the compromise 'quantum' equilibrium.

Load-bearing premise

The load-bearing premise is that the final state has constant flavor-diagonal densities and sits exactly at the edge of collisional instability; the paper takes this from two numerical runs rather than deriving it from the equations of motion.

Editorial extensions

If this is right

  • A subgrid scheme for global merger or supernova simulations can set its post-conversion state directly from Eqs. (8)--(12) and (17), using only the classical equilibrium densities and opacities.
  • The asymptotic state retains nonzero flavor coherence at the percent level of the total density, so a faithful subgrid model cannot set coherence to zero after saturation.
  • Including diagonal repopulation changes the qualitative outcome: the system produces a net excess of heavy-lepton flavor neutrinos rather than reaching flavor equipartition, as shown by the comparison in Fig. 4.
  • The relaxation toward the quantum equilibrium proceeds through repeated instability-relaxation cycles, with the first cycle lasting about $180\,\mu\mathrm{s}$ in both studied points, so the long approach time may matter for the background evolution.
  • The same edge-of-instability construction extends formally to four species with independent $\nu_x$ and $\bar{\nu}_x$ opacities, which would be relevant once muons are included in the simulation.

Reading between the lines

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

  • The marginal-stability condition may be a general attractor for collisional flavor conversion, so the same algebraic recipe could survive in multienergy or weakly inhomogeneous systems where a single eigenmode dominates; the paper does not establish this.
  • If the predicted quantum equilibrium holds, the shift in heavy-lepton densities and the residual coherence could leave a signature in the neutrino emission or in the electron fraction evolution of a merger, though the paper does not compute such observables.
  • The repeated instability-relaxation cycles suggest that collisional flavor conversion may be intermittent or bursting on the $\sim$100 microsecond scale in environments where the background evolves slowly; a longer simulation would test this prediction.
  • The comparison with off-diagonal-only collision terms indicates that the choice of collision operator is not a detail but a matter of principle for the final state, which may also apply to fast flavor conversions with damping.
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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

3 major / 5 minor

Summary. The paper studies the nonlinear outcome of collisional flavor instabilities (CFIs) in a homogeneous, isotropic, monochromatic, two-flavor neutrino gas with a relaxation-time collision term that includes both coherence damping and return to the classical steady state. For two neutron-star-merger snapshot points, the author numerically integrates the QKEs and observes that the late-time state has constant diagonal densities and sits at the edge of collisional instability. From these two conditions, together with the assumption of a non-resonancelike regime, he derives closed-form expressions, Eqs. (8)-(12) and (17), for the asymptotic diagonal densities and the residual flavor coherence, and shows that they reproduce the numerical curves. The paper argues that including diagonal collision terms changes the outcome from flavor equipartition to a 'quantum equilibrium' with nonzero coherence, and it discusses the associated relaxation timescale.

Significance. If correct, the formulas are the first explicit analytic prediction of the CFI saturation state and could serve as a subgrid closure. The algebra is clean, the numerical method is tested for convergence in Appendix B, and no free parameters are tuned. The weakness is that the central selection rule—marginal stability—is inferred from the same two simulations used for validation, and its generality is not tested in resonancelike, multienergy, or inhomogeneous regimes. Hence the significance is currently conditional.

major comments (3)
  1. [Sec. III C-D] The predicted state is uniquely fixed by conditions (i) and (ii), but condition (ii) is an ansatz. In Sec. III D it is recast as constancy of R, Rbar and preservation of the unstable-eigenvector ratio (16f), both read off the two simulations in Fig. 2. The QKEs have no apparent term that selects the Im Omega = 0 surface, and the paper does not rule out limit cycles, attractors with Im Omega != 0, or states where R/Rbar drifts away from the unstable eigenvector. Both validation points are in the non-resonancelike regime with kappa_x << kappa_e, kappa_bar_e, where Appendix A's simplified eigenvectors hold. Please either (a) derive the marginal-stability condition from the equations of motion, or (b) test it in at least one additional regime—resonancelike parameters, multiple energies, or a different opacity hierarchy—where the eigenvector structure or the condition |G alpha| << A^2 changes. Without this, Eqs. (8)-(12) and (17) are a characterization of the two simulated configurations rather than a generic prediction.
  2. [Sec. III B/III C] Validation is in-sample. The conditions (i)-(ii) are inferred from the same Fig. 2 runs that are then used to confirm Eqs. (11)-(12) and (17), and no error bars or tolerances are given for the extracted asymptotic values. This is not parameter fitting, but it means the two NSM points do not independently test the predictive scheme. A stronger test would use one run (or a separate linear-stability argument) to set the ansatz and a different run to check the prediction, and would quantify the agreement.
  3. [Sec. III C, 'Generalizations'] The extension to nu_x != nu_bar_x is presented as a postulate ('we postulate that these small changes would describe the CFI asymptotic state'), with no numerical support. In that four-species regime, and especially if the resonancelike condition of Appendix A is approached, the simplified eigenvectors (g, gbar) and (1, 1) are not guaranteed to remain valid, and Eq. (16f) would need modification. The abstract and outlook describe the result as a first explicit prediction usable in subgrid models; this claim should be confined to the monochromatic, homogeneous, isotropic, non-resonancelike class until the selection rule and eigenvector structure are tested more broadly.
minor comments (5)
  1. [Eq. (7)] As typeset, Im(Omega_-) and Im(Omega_+) are identical; if this is not a rendering artifact, it conflicts with Eq. (A8), where the plus eigenvalue has an additional g - gbar term. Please correct the equation or clarify the notation.
  2. [Fig. 2] The label 'Quantum eqb.' on the right panel does not identify which curve it refers to. Please specify in the caption that the dashed lines are the predictions of Eqs. (11)-(12) and (17).
  3. [Table I and Sec. III B] The caption should state explicitly that Point A has the minus mode unstable and Point B has the plus mode unstable, since the text repeatedly relies on this distinction.
  4. [Eq. (18)] The sentence 'We can show' is not a derivation; please include the intermediate steps or place the calculation in an appendix.
  5. [Sec. III E] The symmetry argument leading to Eq. (21), and the factor of 2, are not fully transparent; please clarify how the turnaround point 2 Nxx^(infinity) - Nxx^(=) gives the quoted relaxation time.

Circularity Check

1 steps flagged · score 2.0 of 10

Mild in-sample circularity: the edge-of-instability ansatz is read off the same simulations used to validate the prediction, but no parameter is fitted and the algebra is genuine.

  1. fitted input called prediction [Sec. III C, Eqs. (8)-(12)]
    "As indicated by the numerical results of Fig. 2, this asymptotic state is characterized by (i) constant flavor-diagonal number densities, and (ii) a configuration lying at the edge of collisional instability."

    The asymptotic-state 'prediction' is not derived from the QKEs alone; it is the algebraic solution of Eq. (8), which is condition (i), combined with Eq. (9) or (10), which is condition (ii). Conditions (i)-(ii) were inferred from the two numerical runs in Fig. 2, and the same runs are then used to claim 'perfect agreement' with the prediction. Thus the validation is in-sample: the selection rule Im(Omega)=0 is an empirical input read off the target data, and the formula is forced once that rule is imposed. No free parameter is tuned, so this is not a statistical fit, but the central predictive content is the ansatz itself rather than an independent out-of-sample consequence.

full rationale

The derivation is self-contained once the two conditions in Sec. III C are granted: Eqs. (8)-(12) and (17) follow algebraically from the QKEs and the stated steady-state/marginal-stability conditions. The circularity is real but mild and explicitly disclosed: the conditions are an ansatz extracted from the same numerical solutions that are later used to validate the 'prediction,' so the agreement in Fig. 2 is a consistency check rather than an independent test. There is no hidden parameter fit, no load-bearing self-citation chain, and the paper candidly labels the nu_x != nu_bar_x generalization as a postulate. The principal epistemic risk is external validity (whether the edge-of-instability attractor holds in multienergy, inhomogeneous, or resonancelike regimes), which is a limitation rather than a constructional circularity.

Assumptions & free parameters 0 free parameters · 6 assumptions · 0 invented entities

The central prediction rests on the relaxation-time collision model and the posited marginal-stability condition. No free parameters are fitted; all numerical inputs are physical quantities from the NSM simulation. The ad hoc elements are the edge-of-instability ansatz and the non-resonancelike restriction.

assumptions (6)
  • domain assumption Relaxation-time approximation for the collision term, with diagonal relaxation to a classical steady state and off-diagonal damping (Eq. 1).
    The physical collision term is replaced by this simple form; for heavy-lepton neutrinos, the steady state is an effective description of escape (Sec. II A).
  • domain assumption The system is homogeneous, isotropic, two-flavor, and single-energy.
    Motivated by [56] for homogeneous mode dominance and by the need for analytic tractability; limitations discussed in Sec. V.
  • domain assumption Initial neutrino distributions equal the classical steady state N^cl.
    Allows the study to focus on the instability without diagonal transients (Sec. II A).
  • ad hoc to paper The asymptotic state has constant flavor-diagonal densities and lies at the edge of collisional instability (Im Omega = 0).
    Conditions (i)-(ii) in Sec. III C are inferred from the numerical solutions, not derived.
  • ad hoc to paper The system stays outside the resonancelike regime, so the simplified eigenvectors (g, bar g) and (1,1) apply.
    Assumed in Sec. II B and Appendix A; stated to hold for the examples.
  • domain assumption Nxx approximately equals Nbar_xx throughout the evolution.
    Observed numerically because the vacuum term is subdominant; used to reduce steady-state equations (Sec. III B).

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Cite this review

Pith. "Pith review of Predicting the outcome of collisional neutrino flavor conversion." pith.science (2026). https://pith.science/paper/G4DVPUYY

@misc{pith2026250516961,
  author       = {Pith},
  title        = {Pith review of: Predicting the outcome of collisional neutrino flavor conversion},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/G4DVPUYY}},
  note         = {Machine review of arXiv:2505.16961}
}
read the original abstract

Collisional flavor instabilities, driven by differing neutrino and antineutrino reaction rates, are expected to occur in dense astrophysical environments like supernovae and neutron star mergers, but have yet to be incorporated in large-scale simulations. We derive analytical expressions for the asymptotic state resulting from a homogeneous and isotropic instability, and apply these predictions to two representative conditions from a neutron star merger simulation. We emphasize the importance of using a collision term that allows for both damping of flavor coherence and relaxation back to the classical steady state. When this classical configuration is collisional-unstable, the resulting asymptotic state reflects a compromise between classical relaxation and flavor conversion, defining a "quantum" equilibrium with nonzero coherence. This analysis highlights the possibility of a tradeoff between classical and quantum effects, an important feature with regard to the inclusion of flavor oscillation physics into global simulations.

Figures

Figures reproduced from arXiv: 2505.16961 by the authors.

Figure 1
Figure 1. FIG. 1. Poloidal slice from the 7 ms postmerger snapshot of [PITH_FULL_IMAGE:figures/full_fig_p003_1.png] view at source ↗
Figure 2
Figure 2. FIG. 2. Evolution of the number density flavor on-diagonal (top panels) and off-diagonal (middle panels) components for Point [PITH_FULL_IMAGE:figures/full_fig_p004_2.png] view at source ↗
Figure 3
Figure 3. FIG. 3. Conservation of the unstable eigenvector structure in [PITH_FULL_IMAGE:figures/full_fig_p006_3.png] view at source ↗
Figures from the paper (2 more)
Figure 4
Figure 4. Figure 4: FIG. 4. Number density evolution for Point A (left) and B (right), with different treatments of the collision term: full term as [PITH_FULL_IMAGE:figures/full_fig_p007_4.png]
Figure 5
Figure 5. Figure 5: FIG. 5. Modification of the evolution for different attenuation [PITH_FULL_IMAGE:figures/full_fig_p009_5.png]

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Cited by 1 Pith paper

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

  1. Comparative Testing of Subgrid Models for Fast Neutrino Flavor Conversions in Core-collapse Supernova Simulations

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Reference graph

Works this paper leans on

88 extracted references · 6 canonical work pages · cited by 1 Pith paper

  1. [1]

    H. T. Janka, T. Melson, and A. Summa, Physics of Core-Collapse Supernovae in Three Dimensions: a Sneak Preview, Ann. Rev. Nucl. Part. Sci. 66, 341 (2016), arXiv:1602.05576 [astro-ph.SR]

    arXiv 2016

  2. [2]

    Burrows and D

    A. Burrows and D. Vartanyan, Core-Collapse Su- pernova Explosion Theory, Nature 589, 29 (2021), arXiv:2009.14157 [astro-ph.SR]

    arXiv 2021

  3. [3]

    Kyutoku, M

    K. Kyutoku, M. Shibata, and K. Taniguchi, Coalescence of black hole-neutron star binaries, Living Rev. Rel. 24, 5 (2021), arXiv:2110.06218 [astro-ph.HE]

    arXiv 2021

  4. [4]

    Radice, S

    D. Radice, S. Bernuzzi, and A. Perego, The Dynamics of Binary Neutron Star Mergers and GW170817, Ann. Rev. Nucl. Part. Sci. 70, 95 (2020), arXiv:2002.03863 [astro- ph.HE]

    arXiv 2020

  5. [5]

    Mezzacappa, Toward Realistic Models of Core Col- lapse Supernovae: A Brief Review, IAU Symp

    A. Mezzacappa, Toward Realistic Models of Core Col- lapse Supernovae: A Brief Review, IAU Symp. 362, 215 (2020), arXiv:2205.13438 [astro-ph.SR]

    arXiv 2020

  6. [6]

    Kiuchi, General relativistic magnetohydrodynam- ics simulations for binary neutron star mergers, in New Frontiers in GRMHD Simulations , edited by C

    K. Kiuchi, General relativistic magnetohydrodynam- ics simulations for binary neutron star mergers, in New Frontiers in GRMHD Simulations , edited by C. Bambi, Y. Mizuno, S. Shashank, and F. Yuan (Springer Nature Singapore, Singapore, 2025) pp. 529– 572, arXiv:2405.10081 [astro-ph.HE]

    arXiv 2025

  7. [7]

    Mezzacappa, E

    A. Mezzacappa, E. Endeve, O. E. Bronson Messer, and S. W. Bruenn, Physical, numerical, and computational challenges of modeling neutrino transport in core-collapse supernovae, Living Rev. Comput. Astrophys. 6, 4 (2020), arXiv:2010.09013 [astro-ph.HE]

    arXiv 2020

  8. [8]

    Foucart, Neutrino transport in general relativistic neu- tron star merger simulations, Living Rev

    F. Foucart, Neutrino transport in general relativistic neu- tron star merger simulations, Living Rev. Comput. As- trophys. 9, 1 (2023), arXiv:2209.02538 [astro-ph.HE]

    arXiv 2023

Show all 88 references
  1. [9]

    Fischer, G

    T. Fischer, G. Guo, K. Langanke, G. Martinez-Pinedo, Y.-Z. Qian, and M.-R. Wu, Neutrinos and nucleosyn- thesis of elements, Prog. Part. Nucl. Phys. 137, 104107 (2024), arXiv:2308.03962 [astro-ph.HE]

    2024 arXiv

  2. [10]

    Wang and R

    X. Wang and R. Surman, Neutrinos and Heavy Element Nucleosynthesis, in Handbook of Nuclear Physics, edited by I. Tanihata, H. Toki, and T. Kajino (Springer Nature Singapore, Singapore, 2023) pp. 1–19, arXiv:2309.06043 [astro-ph.HE]

    2023 arXiv

  3. [11]

    H. Duan, G. M. Fuller, and Y.-Z. Qian, Collective Neu- trino Oscillations, Annu. Rev. Nucl. Part. Sci. 60, 569 (2010), arXiv:1001.2799 [hep-ph]

    2010 arXiv

  4. [12]

    Mirizzi, I

    A. Mirizzi, I. Tamborra, H.-T. Janka, N. Sa- viano, K. Scholberg, R. Bollig, L. Hudepohl, and S. Chakraborty, Supernova Neutrinos: Production, Os- cillations and Detection, Riv. Nuovo Cim. 39, 1 (2016), arXiv:1508.00785 [astro-ph.HE]

    2016 arXiv

  5. [13]

    Chakraborty, R

    S. Chakraborty, R. Hansen, I. Izaguirre, and G. Raffelt, Collective neutrino flavor conversion: Recent develop- ments, Nucl. Phys. B 908, 366 (2016), arXiv:1602.02766 [hep-ph]

    2016 arXiv

  6. [14]

    Tamborra and S

    I. Tamborra and S. Shalgar, New Developments in Fla- vor Evolution of a Dense Neutrino Gas, Annu. Rev. Nucl. Part. Sci. 71, 165 (2021), arXiv:2011.01948 [astro- ph.HE]

    2021 arXiv

  7. [15]

    Capozzi and N

    F. Capozzi and N. Saviano, Neutrino Flavor Conversions in High-Density Astrophysical and Cosmological Envi- ronments, Universe 8, 94 (2022), arXiv:2202.02494 [hep- ph]

    2022 arXiv

  8. [16]

    M. C. Volpe, Neutrinos from dense environments: Fla- vor mechanisms, theoretical approaches, observations, and new directions, Rev. Mod. Phys. 96, 025004 (2024), arXiv:2301.11814 [hep-ph]

    2024 arXiv

  9. [17]

    Richers and M

    S. Richers and M. Sen, Fast Flavor Transformations, in Handbook of Nuclear Physics, edited by I. Tanihata, H. Toki, and T. Kajino (Springer Nature Singapore, Sin- gapore, 2022) pp. 1–17, arXiv:2207.03561 [astro-ph.HE]

    2022 arXiv

  10. [18]

    Johns, S

    L. Johns, S. Richers, and M.-R. Wu, Neutrino Oscil- lations in Core-Collapse Supernovae and Neutron Star Mergers, arXiv:2503.05959 [astro-ph.HE] (2025)

    2025 arXiv

  11. [19]

    C. J. Stapleford, C. Fr¨ ohlich, and J. P. Kneller, Cou- pling Neutrino Oscillations and Simulations of Core- Collapse Supernovae, Phys. Rev. D 102, 081301 (2020), arXiv:1910.04172 [astro-ph.HE]

    2020 arXiv

  12. [20]

    Ehring, S

    J. Ehring, S. Abbar, H.-T. Janka, G. Raffelt, and I. Tam- borra, Fast neutrino flavor conversion in core-collapse su- pernovae: A parametric study in 1D models, Phys. Rev. D 107, 103034 (2023), arXiv:2301.11938 [astro-ph.HE]

    2023 arXiv

  13. [21]

    Ehring, S

    J. Ehring, S. Abbar, H.-T. Janka, G. Raffelt, and I. Tam- borra, Fast Neutrino Flavor Conversions Can Help and Hinder Neutrino-Driven Explosions, Phys. Rev. Lett. 11 131, 061401 (2023), arXiv:2305.11207 [astro-ph.HE]

    2023 arXiv

  14. [22]

    K. Mori, T. Takiwaki, K. Kotake, and S. Horiuchi, Three- dimensional core-collapse supernova models with phe- nomenological treatment of neutrino flavor conversions, Publ. Astron. Soc. Jap. 77, L9 (2025), arXiv:2501.15256 [astro-ph.HE]

    2025 arXiv

  15. [23]

    Li and D

    X. Li and D. M. Siegel, Neutrino Fast Flavor Conver- sions in Neutron-Star Postmerger Accretion Disks, Phys. Rev. Lett. 126, 251101 (2021), arXiv:2103.02616 [astro- ph.HE]

    2021 arXiv

  16. [24]

    O. Just, S. Abbar, M.-R. Wu, I. Tamborra, H.-T. Janka, and F. Capozzi, Fast neutrino conversion in hydrody- namic simulations of neutrino-cooled accretion disks, Phys. Rev. D 105, 083024 (2022), arXiv:2203.16559 [astro-ph.HE]

    2022 arXiv

  17. [25]

    Fern´ andez, S

    R. Fern´ andez, S. Richers, N. Mulyk, and S. Fahlman, Fast flavor instability in hypermassive neutron star disk outflows, Phys. Rev. D 106, 103003 (2022), arXiv:2207.10680 [astro-ph.HE]

    2022 arXiv

  18. [26]

    Y. Qiu, D. Radice, S. Richers, and M. Bhattacharyya, Neutrino Flavor Transformation in Neutron Star Merg- ers, arXiv:2503.11758 [astro-ph.HE] (2025)

    2025 arXiv

  19. [27]

    Nagakura and M

    H. Nagakura and M. Zaizen, Time-Dependent and Qua- sisteady Features of Fast Neutrino-Flavor Conversion, Phys. Rev. Lett. 129, 261101 (2022), arXiv:2206.04097 [astro-ph.HE]

    2022 arXiv

  20. [28]

    Xiong, M.-R

    Z. Xiong, M.-R. Wu, G. Martinez-Pinedo, T. Fischer, M. George, C.-Y. Lin, and L. Johns, Evolution of colli- sional neutrino flavor instabilities in spherically symmet- ric supernova models, Phys. Rev. D 107, 083016 (2023), arXiv:2210.08254 [astro-ph.HE]

    2023 arXiv

  21. [29]

    Nagakura and M

    H. Nagakura and M. Zaizen, Connecting small-scale to large-scale structures of fast neutrino-flavor conver- sion, Phys. Rev. D 107, 063033 (2023), arXiv:2211.01398 [astro-ph.HE]

    2023 arXiv

  22. [30]

    Nagakura, Roles of Fast Neutrino-Flavor Conver- sion on the Neutrino-Heating Mechanism of Core- Collapse Supernova, Phys

    H. Nagakura, Roles of Fast Neutrino-Flavor Conver- sion on the Neutrino-Heating Mechanism of Core- Collapse Supernova, Phys. Rev. Lett. 130, 211401 (2023), arXiv:2301.10785 [astro-ph.HE]

    2023 arXiv

  23. [31]

    Nagakura, Global features of fast neutrino-flavor con- version in binary neutron star mergers, Phys

    H. Nagakura, Global features of fast neutrino-flavor con- version in binary neutron star mergers, Phys. Rev. D 108, 103014 (2023), arXiv:2306.10108 [astro-ph.HE]

    2023 arXiv

  24. [32]

    Shalgar and I

    S. Shalgar and I. Tamborra, Neutrino quantum ki- netics in a core-collapse supernova, JCAP 09, 021, arXiv:2406.09504 [astro-ph.HE]

    arXiv

  25. [33]

    Myers, T

    M. Myers, T. Cooper, M. Warren, J. Kneller, G. McLaughlin, S. Richers, E. Grohs, and C. Frohlich, Neutrino flavor mixing with moments, Phys. Rev. D105, 123036 (2022), arXiv:2111.13722 [hep-ph]

    2022 arXiv

  26. [34]

    Grohs, S

    E. Grohs, S. Richers, S. M. Couch, F. Foucart, J. P. Kneller, and G. C. McLaughlin, Neutrino fast flavor in- stability in three dimensions for a neutron star merger, Phys. Lett. B 846, 138210 (2023), arXiv:2207.02214 [hep- ph]

    2023 arXiv

  27. [35]

    Grohs, S

    E. Grohs, S. Richers, S. M. Couch, F. Foucart, J. Froustey, J. P. Kneller, and G. C. McLaughlin, Two- moment Neutrino Flavor Transformation with Appli- cations to the Fast Flavor Instability in Neutron Star Mergers, Astrophys. J. 963, 11 (2024), arXiv:2309.00972 [astro-ph.HE]

    2024 arXiv

  28. [36]

    Froustey, S

    J. Froustey, S. Richers, E. Grohs, S. D. Flynn, F. Foucart, J. P. Kneller, and G. C. McLaughlin, Neutrino fast flavor oscillations with moments: Linear stability analysis and application to neutron star mergers, Phys. Rev. D 109, 043046 (2024), arXiv:2311.11968 [astro-ph.HE]

    2024 arXiv

  29. [37]

    Froustey, J

    J. Froustey, J. P. Kneller, and G. C. McLaughlin, Quan- tum maximum entropy closure for small flavor coherence, Phys. Rev. D 111, 063022 (2025), arXiv:2409.05807 [hep- ph]

    2025 arXiv

  30. [38]

    J. P. Kneller, J. Froustey, E. B. Grohs, F. Foucart, G. C. McLaughlin, and S. Richers, Quantum closures for neutrino moment transport, Phys. Rev. D 111, 063046 (2025), arXiv:2410.00719 [hep-ph]

    2025 arXiv

  31. [39]

    Grohs, S

    E. Grohs, S. Richers, J. Froustey, F. Foucart, J. P. Kneller, and G. C. McLaughlin, Advection algorithms for quantum neutrino moment transport, Phys. Rev. D 111, 083018 (2025), arXiv:2501.07540 [astro-ph.HE]

    2025 arXiv

  32. [40]

    Nagakura, L

    H. Nagakura, L. Johns, and M. Zaizen, Bhatnagar- Gross-Krook subgrid model for neutrino quantum kinet- ics, Phys. Rev. D 109, 083013 (2024), arXiv:2312.16285 [astro-ph.HE]

    2024 arXiv

  33. [41]

    Bhattacharyya and B

    S. Bhattacharyya and B. Dasgupta, Fast Flavor Depo- larization of Supernova Neutrinos, Phys. Rev. Lett. 126, 061302 (2021), arXiv:2009.03337 [hep-ph]

    2021 arXiv

  34. [42]

    Bhattacharyya and B

    S. Bhattacharyya and B. Dasgupta, Elaborating the ul- timate fate of fast collective neutrino flavor oscillations, Phys. Rev. D 106, 103039 (2022), arXiv:2205.05129 [hep- ph]

    2022 arXiv

  35. [43]

    Zaizen and H

    M. Zaizen and H. Nagakura, Simple method for deter- mining asymptotic states of fast neutrino-flavor conver- sion, Phys. Rev. D 107, 103022 (2023), arXiv:2211.09343 [astro-ph.HE]

    2023 arXiv

  36. [44]

    Zaizen and H

    M. Zaizen and H. Nagakura, Characterizing quasisteady states of fast neutrino-flavor conversion by stability and conservation laws, Phys. Rev. D 107, 123021 (2023), arXiv:2304.05044 [astro-ph.HE]

    2023 arXiv

  37. [45]

    Nagakura and M

    H. Nagakura and M. Zaizen, Basic characteristics of neu- trino flavor conversions in the postshock regions of core- collapse supernova, Phys. Rev. D 108, 123003 (2023), arXiv:2308.14800 [astro-ph.HE]

    2023 arXiv

  38. [46]

    Abbar, M.-R

    S. Abbar, M.-R. Wu, and Z. Xiong, Physics-informed neural networks for predicting the asymptotic outcome of fast neutrino flavor conversions, Phys. Rev. D 109, 043024 (2024), arXiv:2311.15656 [astro-ph.HE]

    2024 arXiv

  39. [47]

    Xiong, M.-R

    Z. Xiong, M.-R. Wu, M. George, and C.-Y. Lin, Robust Integration of Fast Flavor Conversions in Classical Neu- trino Transport, Phys. Rev. Lett. 134, 051003 (2025), arXiv:2403.17269 [astro-ph.HE]

    2025 arXiv

  40. [48]

    Richers, J

    S. Richers, J. Froustey, S. Ghosh, F. Foucart, and J. Gomez, Asymptotic-state prediction for fast flavor transformation in neutron star mergers, Phys. Rev. D 110, 103019 (2024), arXiv:2409.04405 [astro-ph.HE]

    2024 arXiv

  41. [49]

    George, Z

    M. George, Z. Xiong, M.-R. Wu, and C.-Y. Lin, Evolution and the quasistationary state of collective fast neutrino flavor conversion in three dimensions without axisymme- try, Phys. Rev. D 110, 123018 (2024), arXiv:2409.08833 [astro-ph.HE]

    2024 arXiv

  42. [50]

    K. A. Lund, P. Mukhopadhyay, J. M. Miller, and G. C. McLaughlin, Angle-dependent in Situ Fast Flavor Trans- formations in Post-neutron-star-merger Disks, Astro- phys. J. Lett. 985, L9 (2025), arXiv:2503.23727 [astro- ph.HE]

    2025 arXiv

  43. [51]

    Wang and A

    T. Wang and A. Burrows, The Effect of the Fast- Flavor Instability on Core-Collapse Supernova Models, arXiv:2503.04896 [astro-ph.HE] (2025)

    2025 arXiv

  44. [52]

    Johns, Collisional Flavor Instabilities of Super- nova Neutrinos, Phys

    L. Johns, Collisional Flavor Instabilities of Super- nova Neutrinos, Phys. Rev. Lett. 130, 191001 (2023), arXiv:2104.11369 [hep-ph]. 12

    2023 arXiv

  45. [53]

    Xiong, L

    Z. Xiong, L. Johns, M.-R. Wu, and H. Duan, Collisional flavor instability in dense neutrino gases, Phys. Rev. D 108, 083002 (2023), arXiv:2212.03750 [hep-ph]

    2023 arXiv

  46. [54]

    Lin and H

    Y.-C. Lin and H. Duan, Collision-induced flavor instability in dense neutrino gases with energy- dependent scattering, Phys. Rev. D 107, 083034 (2023), arXiv:2210.09218 [hep-ph]

    2023 arXiv

  47. [55]

    Padilla-Gay, I

    I. Padilla-Gay, I. Tamborra, and G. G. Raffelt, Neutrino fast flavor pendulum. II. Collisional damping, Phys. Rev. D 106, 103031 (2022), arXiv:2209.11235 [hep-ph]

    2022 arXiv

  48. [56]

    J. Liu, M. Zaizen, and S. Yamada, Systematic study of the resonancelike structure in the collisional flavor in- stability of neutrinos, Phys. Rev. D 107, 123011 (2023), arXiv:2302.06263 [hep-ph]

    2023 arXiv

  49. [57]

    Zaizen, S

    M. Zaizen, S. Richers, H. Nagakura, H. Suzuki, and C. Kato, Inspecting neutrino flavor instabilities during proto-neutron star cooling phase in supernova: I. Spher- ically symmetric model, arXiv:2407.20548 [astro-ph.HE] (2024)

    2024 arXiv

  50. [58]

    Shalgar and I

    S. Shalgar and I. Tamborra, Do neutrinos become flavor unstable due to collisions with matter in the supernova decoupling region?, Phys. Rev. D 109, 103011 (2024), arXiv:2307.10366 [astro-ph.HE]

    2024 arXiv

  51. [59]

    J. Liu, H. Nagakura, R. Akaho, A. Ito, M. Zaizen, and S. Yamada, Universality of the neutrino collisional flavor instability in core-collapse supernovae, Phys. Rev. D108, 123024 (2023), arXiv:2310.05050 [astro-ph.HE]

    2023 arXiv

  52. [60]

    Akaho, J

    R. Akaho, J. Liu, H. Nagakura, M. Zaizen, and S. Ya- mada, Collisional and fast neutrino flavor instabilities in two-dimensional core-collapse supernova simulation with Boltzmann neutrino transport, Phys. Rev. D109, 023012 (2024), arXiv:2311.11272 [astro-ph.HE]

    2024 arXiv

  53. [61]

    J. Liu, H. Nagakura, R. Akaho, A. Ito, M. Zaizen, S. Fu- rusawa, and S. Yamada, Muon-induced collisional flavor instability in core-collapse supernova, Phys. Rev. D 110, 043039 (2024), arXiv:2407.10604 [hep-ph]

    2024 arXiv

  54. [62]

    Xiong, M.-R

    Z. Xiong, M.-R. Wu, M. George, C.-Y. Lin, N. K. Largani, T. Fischer, and G. Martinez-Pinedo, Fast neu- trino flavor conversions in a supernova: Emergence, evo- lution, and effects, Phys. Rev. D 109, 123008 (2024), arXiv:2402.19252 [astro-ph.HE]

    2024 arXiv

  55. [63]

    Nagakura, K

    H. Nagakura, K. Sumiyoshi, S. Fujibayashi, Y. Sekiguchi, and M. Shibata, Neutrino flavor instabilities in a binary neutron star merger remnant: Roles of a long-lived hy- permassive neutron star, arXiv:2504.20143 [astro-ph.HE] (2025)

    2025 arXiv

  56. [64]

    D. F. G. Fiorillo, I. Padilla-Gay, and G. G. Raffelt, Col- lisions and collective flavor conversion: Integrating out the fast dynamics, Phys. Rev. D 109, 063021 (2024), arXiv:2312.07612 [hep-ph]

    2024 arXiv

  57. [65]

    Johns and S

    L. Johns and S. Rodriguez, Collisional flavor pendula and neutrino quantum thermodynamics, arXiv:2312.10340 [hep-ph] (2023)

    2023 arXiv

  58. [66]

    Zaizen, Spectral diversity in collisional neutrino-flavor conversion: Flavor equipartition or swap, Phys

    M. Zaizen, Spectral diversity in collisional neutrino-flavor conversion: Flavor equipartition or swap, Phys. Rev. D 111, 103029 (2025), arXiv:2502.09260 [hep-ph]

    2025 arXiv

  59. [67]

    C. Kato, H. Nagakura, and L. Johns, Collisional flavor swap with neutrino self-interactions, Phys. Rev. D 109, 103009 (2024), arXiv:2309.02619 [astro-ph.HE]

    2024 arXiv

  60. [68]

    Sigl and G

    G. Sigl and G. Raffelt, General kinetic description of rel- ativistic mixed neutrinos, Nucl. Phys. B 406, 423 (1993)

    1993

  61. [69]

    S. A. Richers, G. C. McLaughlin, J. P. Kneller, and A. Vlasenko, Neutrino Quantum Kinetics in Compact Objects, Phys. Rev. D 99, 123014 (2019), [Erratum: Phys. Rev. D 109, 129902(E) (2024)], arXiv:1903.00022 [astro-ph.HE]

    2019 arXiv

  62. [70]

    Zhang and A

    Y. Zhang and A. Burrows, Transport Equations for Os- cillating Neutrinos, Phys. Rev. D 88, 105009 (2013), arXiv:1310.2164 [hep-ph]

    2013 arXiv

  63. [71]

    Navas et al.(Particle Data Group), Review of particle physics, Phys

    S. Navas et al.(Particle Data Group), Review of particle physics, Phys. Rev. D 110, 030001 (2024)

    2024

  64. [72]

    Foucart, P

    F. Foucart, P. C.-K. Cheong, M. D. Duez, L. E. Kid- der, H. P. Pfeiffer, and M. A. Scheel, Robustness of neu- tron star merger simulations to changes in neutrino trans- port and neutrino-matter interactions, Phys. Rev. D110, 083028 (2024), arXiv:2407.15989 [astro-ph.HE]

    2024 arXiv

  65. [73]

    O’Connor, An Open-Source Neutrino Radiation Hy- drodynamics Code for Core-Collapse Supernovae, Astro- phys

    E. O’Connor, An Open-Source Neutrino Radiation Hy- drodynamics Code for Core-Collapse Supernovae, Astro- phys. J. Suppl. 219, 24 (2015), arXiv:1411.7058 [astro- ph.HE]

    2015 arXiv

  66. [74]

    Virtanen et al., SciPy 1.0: Fundamental Algorithms for Scientific Computing in Python, Nature Methods 17, 261 (2020)

    P. Virtanen et al., SciPy 1.0: Fundamental Algorithms for Scientific Computing in Python, Nature Methods 17, 261 (2020)

    2020

  67. [75]

    D. F. G. Fiorillo and G. G. Raffelt, Fast Flavor Conver- sions at the Edge of Instability in a Two-Beam Model, Phys. Rev. Lett. 133, 221004 (2024), arXiv:2403.12189 [hep-ph]

    2024 arXiv

  68. [76]

    D. F. G. Fiorillo and G. G. Raffelt, Theory of neutrino fast flavor evolution. Part II. Solutions at the edge of in- stability, J. High Energy Phys.12, 205, arXiv:2409.17232 [hep-ph]

    arXiv

  69. [77]

    D. F. G. Fiorillo and G. G. Raffelt, Theory of neu- trino slow flavor evolution. Part I. Homogeneous medium, JHEP 04, 146, arXiv:2412.02747 [hep-ph]

    arXiv

  70. [78]

    D. F. G. Fiorillo and G. G. Raffelt, Collective Flavor Conversions Are Interactions of Neutrinos with Quan- tized Flavor Waves, Phys. Rev. Lett.134, 211003 (2025), arXiv:2502.06935 [hep-ph]

    2025 arXiv

  71. [79]

    Johns, Thermodynamics of oscillating neutrinos, arXiv:2306.14982 [hep-ph] (2023)

    L. Johns, Thermodynamics of oscillating neutrinos, arXiv:2306.14982 [hep-ph] (2023)

    2023

  72. [80]

    Bollig, H

    R. Bollig, H. T. Janka, A. Lohs, G. Martinez-Pinedo, C. J. Horowitz, and T. Melson, Muon Creation in Su- pernova Matter Facilitates Neutrino-driven Explosions, Phys. Rev. Lett. 119, 242702 (2017), arXiv:1706.04630 [astro-ph.HE]

    2017 arXiv

  73. [81]

    Fischer, G

    T. Fischer, G. Guo, G. Martinez-Pinedo, M. Liebend¨ orfer, and A. Mezzacappa, Muonization of supernova matter, Phys. Rev. D 102, 123001 (2020), arXiv:2008.13628 [astro-ph.HE]

    2020 arXiv

  74. [82]

    Loffredo, A

    E. Loffredo, A. Perego, D. Logoteta, and M. Branchesi, Muons in the aftermath of neutron star mergers and their impact on trapped neutrinos, Astron. Astrophys. 672, A124 (2023), arXiv:2209.04458 [astro-ph.HE]

    2023 arXiv

  75. [83]

    H. H.-Y. Ng, C. Musolino, S. D. Tootle, and L. Rezzolla, Accurate Muonic Interactions in Neutron Star Mergers and Impact on Heavy-element Nucleosynthesis, Astro- phys. J. Lett. 985, L36 (2025), arXiv:2411.19178 [astro- ph.HE]

    2025 arXiv

  76. [84]

    M. A. Pajkos and E. R. Most, Influence of muons, pions, and trapped neutrinos on neutron star mergers, Phys. Rev. D 111, 043013 (2025), arXiv:2409.09147 [astro- ph.HE]

    2025 arXiv

  77. [85]

    J. Liu, H. Nagakura, M. Zaizen, L. Johns, and S. Ya- mada, Asymptotic states of fast neutrino-flavor conver- sions in the three-flavor framework, Phys. Rev. D 111, 123004 (2025), arXiv:2503.18145 [astro-ph.HE]

    2025 arXiv

  78. [86]

    Bhattacharyya, M.-R

    S. Bhattacharyya, M.-R. Wu, and Z. Xiong, Role of Mat- ter Inhomogeneity on Fast Flavor Conversion of Super- 13 nova Neutrinos, arXiv:2504.11316 [astro-ph.HE] (2025)

    2025 arXiv

  79. [87]

    Froustey, C

    J. Froustey, C. Pitrou, and M. C. Volpe, Neutrino decou- pling including flavour oscillations and primordial nucle- osynthesis, JCAP 12, 015, arXiv:2008.01074 [hep-ph]

    2008 arXiv

  80. [88]

    Froustey and C

    J. Froustey and C. Pitrou, Primordial neutrino asymme- try evolution with full mean-field effects and collisions, JCAP 03 (03), 065, arXiv:2110.11889 [hep-ph]

    arXiv

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