pith. sign in

arxiv: 2512.18549 · v2 · pith:SSAURH7Fnew · submitted 2025-12-21 · ⚛️ nucl-th · astro-ph.HE· cond-mat.quant-gas

Superfluid fraction in the crystal phase of the inner crust of neutron stars

Pith reviewed 2026-05-25 07:47 UTC · model grok-4.3

classification ⚛️ nucl-th astro-ph.HEcond-mat.quant-gas
keywords neutron starsinner crustsuperfluid fractionHartree-Fock-BogoliubovSkyrme energy density functionalBloch boundary conditionspulsar glitchespairing
0
0 comments X

The pith

Above 0.03 fm^{-3} density, over 90% of neutrons in the inner crust are superfluid, independent of interaction details.

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

The paper performs fully self-consistent Hartree-Fock-Bogoliubov calculations with Skyrme functionals and separable pairing to model the crystal lattice of nuclear clusters immersed in a neutron gas. It imposes Bloch boundary conditions and a time-independent relative flow to generate a phase gradient in the order parameter, from which the superfluid fraction is extracted via the resulting current in the superfluid rest frame. The calculations find that this fraction exceeds 90% at densities above 0.03 fm^{-3} and remains high across choices of interaction, cluster charge, and lattice geometry, approaching the hydrodynamic limit for strong pairing. This result implies the inner crust alone supplies enough superfluid angular momentum to account for observed pulsar glitches.

Core claim

Within the crystal phase of the inner crust, a relative flow between clusters and the surrounding neutron gas induces a phase in the complex order parameter; the neutron superfluid fraction extracted from the counterflow current exceeds 90% above 0.03 fm^{-3}, is only slightly below the linear-response BCS value, and is nearly independent of the Skyrme parametrization, cluster charge, and lattice geometry.

What carries the argument

Time-independent relative flow between clusters and neutron gas under Bloch boundary conditions in HFB calculations, which develops a phase in the pairing order parameter whose induced current defines the superfluid fraction.

If this is right

  • The inner crust alone can supply the superfluid angular momentum reservoir needed to explain pulsar glitches.
  • The superfluid fraction approaches the hydrodynamic limit when pairing is strong.
  • The result is robust against variations in Skyrme interaction, cluster charge, and lattice geometry.
  • The value lies only slightly below that obtained from linear response on top of BCS theory.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • Similar Bloch-HFB setups could be applied to the pasta phases at higher densities to check whether the high superfluid fraction persists.
  • Glitch rise-time observations might be used to place bounds on the effective pairing strength inside the crust.
  • The near-independence from microscopic details suggests that simplified hydrodynamic models of the crust could be calibrated directly to the 90% figure for glitch modeling.

Load-bearing premise

A time-independent relative flow combined with Bloch boundary conditions produces a phase in the order parameter that accurately quantifies the superfluid fraction through the resulting current.

What would settle it

A calculation or simulation at densities above 0.03 fm^{-3} that yields a superfluid fraction below 80% when the relative flow is replaced by a fully time-dependent dynamical treatment would contradict the central result.

Figures

Figures reproduced from arXiv: 2512.18549 by Giorgio Almirante, Michael Urban, Theodora Kaskitsi.

Figure 1
Figure 1. Figure 1: FIG. 1. Single-particle ( [PITH_FULL_IMAGE:figures/full_fig_p004_1.png] view at source ↗
Figure 3
Figure 3. Figure 3: FIG. 3. Simple cubic lattice section at [PITH_FULL_IMAGE:figures/full_fig_p005_3.png] view at source ↗
Figure 2
Figure 2. Figure 2: FIG. 2. Neutron density ( [PITH_FULL_IMAGE:figures/full_fig_p005_2.png] view at source ↗
Figure 5
Figure 5. Figure 5: FIG. 5. Simple cubic lattice section at [PITH_FULL_IMAGE:figures/full_fig_p006_5.png] view at source ↗
Figure 4
Figure 4. Figure 4: FIG. 4. Simple cubic lattice section at [PITH_FULL_IMAGE:figures/full_fig_p006_4.png] view at source ↗
Figure 6
Figure 6. Figure 6: FIG. 6. Neutron density ( [PITH_FULL_IMAGE:figures/full_fig_p007_6.png] view at source ↗
Figure 7
Figure 7. Figure 7: FIG. 7. Simple cubic lattice section at [PITH_FULL_IMAGE:figures/full_fig_p008_7.png] view at source ↗
Figure 8
Figure 8. Figure 8: FIG. 8. Superfluid fraction [PITH_FULL_IMAGE:figures/full_fig_p009_8.png] view at source ↗
read the original abstract

In the most extended layer of the inner crust of neutron stars, nuclear matter is believed to form a crystal of clusters immersed in a superfluid neutron gas. Here we analyze this phase of matter within fully self-consistent Hartree-Fock-Bogoliubov calculations using Skyrme-type energy density functionals for the mean field and a separable interaction in the pairing channel. The periodicity of the lattice is taken into account using Bloch boundary conditions, in order to describe the interplay between band structure and superfluidity. A relative flow between the clusters and the surrounding neutron gas is introduced in a time-independent way. As a consequence, the complex order parameter develops a phase, and in the rest frame of the superfluid one finds a counterflow between neutrons inside and outside the clusters. The neutron superfluid fraction is computed from the resulting current. Our results indicate that at densities above 0.03 fm$^{-3}$, more than 90% of the neutrons are effectively superfluid, independently of the detailed choice of the interaction, cluster charge, and lattice geometry. This fraction is only slightly lower than the one obtained recently within linear response theory on top of the Bardeen-Cooper-Schrieffer approximation, and it approaches the hydrodynamic limit for strong pairing. As a consequence, it is likely that the inner crust alone can provide a sufficient superfluid angular momentum reservoir to explain pulsar glitches.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

1 major / 2 minor

Summary. The manuscript presents fully self-consistent Hartree-Fock-Bogoliubov (HFB) calculations of the inner crust of neutron stars modeled as a crystal of nuclear clusters immersed in a superfluid neutron gas. Skyrme-type energy density functionals are used for the mean field together with a separable pairing interaction. Lattice periodicity is incorporated via Bloch boundary conditions. A time-independent relative flow is imposed between the clusters and the neutron gas, causing the complex order parameter to acquire a phase; the superfluid fraction is then extracted from the resulting neutron current evaluated in the superfluid rest frame. The central claim is that above 0.03 fm^{-3} more than 90% of the neutrons are effectively superfluid, with this fraction independent of the detailed choice of interaction, cluster charge, and lattice geometry. The result lies close to recent linear-response calculations on top of BCS and approaches the hydrodynamic limit for strong pairing, implying that the inner crust alone can supply a sufficient superfluid angular-momentum reservoir to account for pulsar glitches.

Significance. If the numerical result holds, the work is significant for neutron-star astrophysics. It supplies a quantitative, largely model-independent estimate of the superfluid reservoir in the inner crust and thereby strengthens the case that this layer can explain observed glitch sizes without additional contributions from the core. The methodological combination of fully self-consistent HFB with Bloch boundary conditions for the periodic lattice constitutes a clear advance over simpler approximations, and the reported approach to the hydrodynamic limit for strong pairing provides an internal consistency check. The independence from microscopic details is a noteworthy feature of the findings.

major comments (1)
  1. [Abstract and §3 (computational method)] Abstract and computational-setup description: the extraction of the superfluid fraction from the neutron current that arises after the order parameter acquires a phase under the imposed time-independent relative flow (with Bloch boundary conditions) is load-bearing for both the >90% value and the independence claim. The manuscript should supply an explicit test or derivation (e.g., comparison to the uniform-matter limit or variation of flow velocity) demonstrating that residual entrainment, lattice-induced artifacts, or pairing-channel dependence do not alter the current-to-density ratio across the scanned parameter space.
minor comments (2)
  1. [Figure captions] Figure captions should explicitly list the Skyrme parametrizations, cluster charges, and lattice geometries corresponding to each curve or symbol so that the independence statement can be verified at a glance.
  2. [Results discussion] A short reference or one-line derivation of the hydrodynamic-limit expression for the superfluid fraction would help readers confirm that the numerical results indeed approach this limit for strong pairing.

Simulated Author's Rebuttal

1 responses · 0 unresolved

We thank the referee for the positive evaluation of our work and the constructive suggestion. We address the major comment below.

read point-by-point responses
  1. Referee: [Abstract and §3 (computational method)] Abstract and computational-setup description: the extraction of the superfluid fraction from the neutron current that arises after the order parameter acquires a phase under the imposed time-independent relative flow (with Bloch boundary conditions) is load-bearing for both the >90% value and the independence claim. The manuscript should supply an explicit test or derivation (e.g., comparison to the uniform-matter limit or variation of flow velocity) demonstrating that residual entrainment, lattice-induced artifacts, or pairing-channel dependence do not alter the current-to-density ratio across the scanned parameter space.

    Authors: We agree that an explicit validation of the extraction procedure would strengthen the manuscript. While the reported near-independence from the choice of Skyrme functional (which varies both the mean-field and pairing channels), cluster charge, and lattice geometry, together with the close agreement to linear-response BCS results and the approach to the hydrodynamic limit, already indicates that lattice artifacts and residual entrainment do not dominate, we acknowledge the value of a direct test. In the revised version we will add (i) a comparison to the uniform-matter limit obtained by suppressing the lattice modulation and (ii) a short check confirming that the current-to-density ratio remains stable under small variations of the imposed flow velocity within the linear regime. These additions will be placed in §3 or an appendix. revision: yes

Circularity Check

0 steps flagged

No circularity: superfluid fraction from direct numerical HFB current extraction

full rationale

The paper computes the superfluid fraction by solving the HFB equations with Skyrme functionals and separable pairing under Bloch boundary conditions, imposing a time-independent relative flow, allowing the order parameter to develop a phase, and extracting the fraction from the resulting neutron current in the superfluid rest frame. This is a standard numerical procedure using external functionals; the reported >90% value above 0.03 fm^{-3} (independent of interaction, charge, geometry) emerges from parameter scans rather than reducing by construction to any fitted input or self-citation chain within the paper's own equations. No self-definitional, fitted-input, or uniqueness-imported steps are present in the derivation chain.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 0 invented entities

The work relies on established nuclear energy-density functionals and pairing models from prior literature; the novel element is the numerical implementation with flow and Bloch conditions. No new free parameters are introduced in this study.

axioms (1)
  • domain assumption Bloch boundary conditions accurately capture the periodicity of the nuclear lattice and the interplay between band structure and superfluidity.
    Invoked in the abstract to describe the crystal phase.

pith-pipeline@v0.9.0 · 5788 in / 1496 out tokens · 45940 ms · 2026-05-25T07:47:50.520393+00:00 · methodology

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Lean theorems connected to this paper

Citations machine-checked in the Pith Canon. Every link opens the source theorem in the public Lean library.

What do these tags mean?
matches
The paper's claim is directly supported by a theorem in the formal canon.
supports
The theorem supports part of the paper's argument, but the paper may add assumptions or extra steps.
extends
The paper goes beyond the formal theorem; the theorem is a base layer rather than the whole result.
uses
The paper appears to rely on the theorem as machinery.
contradicts
The paper's claim conflicts with a theorem or certificate in the canon.
unclear
Pith found a possible connection, but the passage is too broad, indirect, or ambiguous to say the theorem truly supports the claim.

Reference graph

Works this paper leans on

71 extracted references · 71 canonical work pages · 1 internal anchor

  1. [1]

    Superfluid fraction in the crystal phase of the inner crust of neutron stars

    predicted a very strong entrainment and thus a small superfluid fraction. This presents a tension with glitch ∗ giorgio.almirante@ijclab.in2p3.fr † theodora.kaskitsi@universite-paris-saclay.fr ‡ michael.urban@ijclab.in2p3.fr observations [20], unless one abandons the assumption that glitches originate solely in the crust [21]. This prediction of band theo...

  2. [2]

    degeneracy

    and the scalar superfluid density isρ S =P i ρii S /3. Working in the frame in which the phase of the pair- ing field is periodic, Eq. (12) implies that the superfluid velocity vanishes (vS = 0) and thus Eq. (10) becomes ⟨ρn⟩= (⟨ρ n⟩ −ρ S)vN .(13) The neutron superfluid density can thus be directly in- ferred from Eq. (13), once densities and currents hav...

  3. [3]

    (9), obtaining quasi-particle energiesE α(pb) and eigenvectors (U ∗ αn(pb),−V ∗ αn(pb))

    We diagonalize it according to Eq. (9), obtaining quasi-particle energiesE α(pb) and eigenvectors (U ∗ αn(pb),−V ∗ αn(pb)). In terms of these, the normal and anomalous density matrices are expressed as ρnn′(pb) = X Eα>0 V ∗ n′α(pb)Vnα(pb),(A6) κnn′(pb) = X Eα>0 U ∗ nα(pb)Vn′α(pb),(A7) withE α =E α(pb). Then, one can compute the densities and pairing field...

  4. [4]

    Neutron star matter at sub-nuclear densities,

    J.W. Negele and D. Vautherin, “Neutron star matter at sub-nuclear densities,” Nucl. Phys. A207, 298–320 (1973)

  5. [5]

    Physics of Neutron Star Crusts,

    N. Chamel and P. Haensel, “Physics of Neutron Star Crusts,” Liv. Rev. Relativity11, 10 (2008)

  6. [6]

    Liquid-gas coexistence versus energy minimization with respect to the density profile in the inhomogeneous inner crust of neutron stars,

    N. Martin and M. Urban, “Liquid-gas coexistence versus energy minimization with respect to the density profile in the inhomogeneous inner crust of neutron stars,” Phys. Rev. C92, 015803 (2015)

  7. [7]

    Uncertainties in the pasta-phase properties of catalysed neutron stars,

    H. Dhin Thi, T. Carreau, A. F. Fantina, and F. Gul- minelli, “Uncertainties in the pasta-phase properties of catalysed neutron stars,” Astron. Astrophys.654, A114 (2021)

  8. [8]

    Thermal and transport prop- erties of the neutron star inner crust,

    D. Page and S. Reddy, “Thermal and transport prop- erties of the neutron star inner crust,” inNeutron star crust, edited by C. A. Bertulani and J. Piekarewicz (Nova Science Publishers, Hauppage, 2012) pp. 281–308

  9. [9]

    Spectrum of shear modes in the neutron- star crust: Estimating the nuclear-physics uncertainties,

    I. Tews, “Spectrum of shear modes in the neutron- star crust: Estimating the nuclear-physics uncertainties,” Phys. Rev. C95, 015803 (2017)

  10. [10]

    Pulsar Glitches and Rest- lessness as a Hard Superfluidity Phenomenon,

    P. W. Anderson and N. Itoh, “Pulsar Glitches and Rest- lessness as a Hard Superfluidity Phenomenon,” Nature 256, 25–27 (1975)

  11. [11]

    Slowly ro- tating superfluid Newtonian neutron star model with en- trainment,

    R. Prix, G. L. Comer, and N. Andersson, “Slowly ro- tating superfluid Newtonian neutron star model with en- trainment,” Astron. Astrophys.381, 178–196 (2002)

  12. [12]

    Effect of entrainment on stress and pulsar glitches in stratified neutron star crust,

    B. Carter and N. Chamel, “Effect of entrainment on stress and pulsar glitches in stratified neutron star crust,” Mon. Not. R. Astron. Soc.368, 796–808 (2006)

  13. [13]

    In- sights Into the Physics of Neutron Star Interiors from Pulsar Glitches,

    M. Antonelli, A. Montoli, and P. M. Pizzochero, “In- sights Into the Physics of Neutron Star Interiors from Pulsar Glitches,” inAstrophysics in the XXI Century with Compact Stars, edited by C. A. Z. Vasconcellos (World Scientific, Singapore, 2022) pp. 219–281

  14. [14]

    On the Superfluid Fraction of an Arbi- trary Many-Body System at T=0,

    A. J. Leggett, “On the Superfluid Fraction of an Arbi- trary Many-Body System at T=0,” J. Stat. Phys.93, 927–941 (1998)

  15. [15]

    J. R. Schrieffer,Theory of superconductivity(Benjamin, New York, 1964)

  16. [16]

    Three-velocity hydro- dynamics of superfluid solutions,

    A. F. Andreev and E. P. Bashkin, “Three-velocity hydro- dynamics of superfluid solutions,” Sov. J. Exp. Theor. Phys.42, 164 (1975)

  17. [17]

    Neutron conduction in the inner crust of a neutron star in the framework of the band theory of solids,

    N. Chamel, “Neutron conduction in the inner crust of a neutron star in the framework of the band theory of solids,” Phys. Rev. C85, 035801 (2012)

  18. [18]

    N. W. Ashcroft and N. D. Mermin,Solid state physics (Saunders, Fort Worth, 1976)

  19. [19]

    Band structure effects for dripped neu- trons in neutron star crust,

    N. Chamel, “Band structure effects for dripped neu- trons in neutron star crust,” Nucl. Phys. A747, 109–128 (2005)

  20. [20]

    Effective mass of free neutrons in neutron star crust,

    N. Chamel, “Effective mass of free neutrons in neutron star crust,” Nucl. Phys. A773, 263–278 (2006)

  21. [21]

    Self-consistent band calculation of the slab phase in the neutron-star crust,

    Y. Kashiwaba and T. Nakatsukasa, “Self-consistent band calculation of the slab phase in the neutron-star crust,” Phys. Rev. C100, 035804 (2019)

  22. [22]

    Time- dependent extension of the self-consistent band theory for neutron star matter: Anti-entrainment effects in the slab phase,

    K. Sekizawa, S. Kobayashi, and M. Matsuo, “Time- dependent extension of the self-consistent band theory for neutron star matter: Anti-entrainment effects in the slab phase,” Phys. Rev. C105, 045807 (2022)

  23. [23]

    Crustal Entrainment and Pulsar Glitches,

    N. Chamel, “Crustal Entrainment and Pulsar Glitches,” Phys. Rev. Lett.110, 011101 (2013)

  24. [24]

    Pulsar Glitches: The Crust is not Enough,

    N. Andersson, K. Glampedakis, W. C. G. Ho, and C. M. Espinoza, “Pulsar Glitches: The Crust is not Enough,” Phys. Rev. Lett.109, 241103 (2012)

  25. [25]

    Superfluid hydrodynamics in the inner crust of neutron stars,

    N. Martin and M. Urban, “Superfluid hydrodynamics in the inner crust of neutron stars,” Phys. Rev. C94, 065801 (2016)

  26. [26]

    Neutron-phonon interaction in neutron stars: phonon spectrum of Coulomb lattice,

    A.D. Sedrakian, “Neutron-phonon interaction in neutron stars: phonon spectrum of Coulomb lattice,” Astrophys. Space Sci.236, 267–276 (1996)

  27. [27]

    In-medium ion mass renormalization and lattice vibrations in the neutron star crust,

    P. Magierski, “In-medium ion mass renormalization and lattice vibrations in the neutron star crust,” Int. J. Mod. Phys. E13, 371–374 (2004)

  28. [28]

    Nuclear hydrodynamics in the inner crust of neutron stars,

    P. Magierski and A. Bulgac, “Nuclear hydrodynamics in the inner crust of neutron stars,” Acta Phys. Pol. B35, 1203–1213 (2004)

  29. [29]

    Nuclear structure and dy- namics in the inner crust of neutron stars,

    P. Magierski and A. Bulgac, “Nuclear structure and dy- namics in the inner crust of neutron stars,” Nucl. Phys. A 738, 143–149 (2004), proceedings of the 8th International Conference on Clustering Aspects of Nuclear Structure and Dynamics

  30. [30]

    Effect of BCS pairing on entrainment in neutron superfluid current in neutron star crust,

    B. Carter, N. Chamel, and P. Haensel, “Effect of BCS pairing on entrainment in neutron superfluid current in neutron star crust,” Nucl. Phys. A759, 441–464 (2005)

  31. [31]

    Superfluid fraction in the crystalline crust of a neutron star: Role of BCS pairing,

    N. Chamel, “Superfluid fraction in the crystalline crust of a neutron star: Role of BCS pairing,” Phys. Rev. C 111, 045803 (2025)

  32. [32]

    Superfluid Density of Neutrons in the Inner Crust of Neutron Stars: New Life for Pulsar Glitch Models,

    G. Watanabe and C. J. Pethick, “Superfluid Density of Neutrons in the Inner Crust of Neutron Stars: New Life for Pulsar Glitch Models,” Phys. Rev. Lett.119, 062701 (2017)

  33. [33]

    Superfluid fraction in the rod phase of the inner crust of neutron stars,

    G. Almirante and M. Urban, “Superfluid fraction in the rod phase of the inner crust of neutron stars,” Phys. Rev. C110, 065802 (2024)

  34. [34]

    Temperature dependence and finite-size effects in collective modes of superfluid-trapped Fermi gases,

    M. Grasso, E. Khan, and M. Urban, “Temperature dependence and finite-size effects in collective modes of superfluid-trapped Fermi gases,” Phys. Rev. A72, 043617 (2005)

  35. [35]

    Formation of a vortex lattice in a rotating BCS Fermi gas,

    G. Tonini, F. Werner, and Y. Castin, “Formation of a vortex lattice in a rotating BCS Fermi gas,” Eur. Phys. J. D39, 283–294 (2006)

  36. [36]

    Effects of pairing gap and band gap on superfluid density in the inner crust of neutron stars,

    Y. Minami and G. Watanabe, “Effects of pairing gap and band gap on superfluid density in the inner crust of neutron stars,” Phys. Rev. Res.4, 033141 (2022)

  37. [37]

    Superfluidity and the moments of inertia of nuclei,

    A. B. Migdal, “Superfluidity and the moments of inertia of nuclei,” Nucl. Phys.13, 655–674 (1959)

  38. [38]

    Time-dependent hartree-fock equations and rotational states of nuclei,

    D. J. Thouless and J. G. Valatin, “Time-dependent hartree-fock equations and rotational states of nuclei,” Nucl. Phys.31, 211–230 (1962)

  39. [39]

    Slow rotation of a superfluid trapped Fermi gas,

    M. Urban and P. Schuck, “Slow rotation of a superfluid trapped Fermi gas,” Phys. Rev. A67, 033611 (2003)

  40. [40]

    Superfluid den- sity in linear response theory: Pulsar glitches from the in- ner crust of neutron stars,

    Giorgio Almirante and Michael Urban, “Superfluid den- sity in linear response theory: Pulsar glitches from the in- ner crust of neutron stars,” Phys. Rev. Lett.135, 132701 (2025)

  41. [41]

    Superfluidity in topologically nontrivial flat bands,

    S. Peotta and P. T¨ orm¨ a, “Superfluidity in topologically nontrivial flat bands,” Nat. Commun.6, 8944 (2015)

  42. [42]

    Band geometry, Berry curvature, and superfluid weight,

    L. Liang, T. I. Vanhala, S. Peotta, T. Siro, A. Harju, and P. T¨ orm¨ a, “Band geometry, Berry curvature, and superfluid weight,” Phys. Rev. B95, 024515 (2017)

  43. [43]

    Cooper pairing, flat-band superconductiv- ity, and quantum geometry in the pyrochlore-hubbard 14 model,

    M. Iskin, “Cooper pairing, flat-band superconductiv- ity, and quantum geometry in the pyrochlore-hubbard 14 model,” Phys. Rev. B109, 174508 (2024)

  44. [44]

    Geometric superfluid weight of composite bands in multiorbital superconductors,

    G. Jiang and Y. Barlas, “Geometric superfluid weight of composite bands in multiorbital superconductors,” Phys. Rev. B109, 214518 (2024)

  45. [45]

    Structure factors and quantum geometry in multiband BCS superconductors,

    M. Iskin, “Structure factors and quantum geometry in multiband BCS superconductors,” Phys. Rev. B112, 014517 (2025)

  46. [46]

    Superfluid fraction in the slab phase of the inner crust of neutron stars,

    G. Almirante and M. Urban, “Superfluid fraction in the slab phase of the inner crust of neutron stars,” Phys. Rev. C109, 045805 (2024)

  47. [47]

    On the Superfluid Fraction and the Hy- drodynamics of Supersolids,

    W. M. Saslow, “On the Superfluid Fraction and the Hy- drodynamics of Supersolids,” J. Low Temp. Phys.169, 248–263 (2012)

  48. [48]

    Superfluidity of Periodic Solids,

    W. M. Saslow, “Superfluidity of Periodic Solids,” Phys. Rev. Lett.36, 1151–1154 (1976)

  49. [49]

    Superfluid Fraction of a 2D Bose-Einstein Condensate in a Trian- gular Lattice,

    F. Rabec, G. Brochier, S. Wattellier, G. Chauveau, Y. Li, S. Nascimbene, J. Dalibard, and J. Beugnon, “Superfluid Fraction of a 2D Bose-Einstein Condensate in a Trian- gular Lattice,” arXiv e-prints (2025), arXiv:2511.04575 [cond-mat.quant-gas]

  50. [50]

    Superfluid extension of the self-consistent time-dependent band theory for neu- tron star matter: Anti-entrainment versus superfluid ef- fects in the slab phase,

    K. Yoshimura and K. Sekizawa, “Superfluid extension of the self-consistent time-dependent band theory for neu- tron star matter: Anti-entrainment versus superfluid ef- fects in the slab phase,” Phys. Rev. C109, 065804 (2024)

  51. [51]

    Yoshimura and K

    K. Yoshimura and K. Sekizawa, “Phase transitions in the inner crust of neutron stars within the superfluid band theory: Competition between 1S0 pairing and spin po- larization under finite temperature and magnetic field,” Phys. Rev. C112, 065804 (2025)

  52. [52]

    A Skyrme parametrization from subnu- clear to neutron star densities,

    E. Chabanat, P. Bonche, P. Haensel, J. Meyer, and R. Schaeffer, “A Skyrme parametrization from subnu- clear to neutron star densities,” Nucl. Phys. A627, 710– 746 (1997)

  53. [53]

    A Skyrme parametrization from subnu- clear to neutron star densities Part II. Nuclei far from stabilities,

    E. Chabanat, P. Bonche, P. Haensel, J. Meyer, and R. Schaeffer, “A Skyrme parametrization from subnu- clear to neutron star densities Part II. Nuclei far from stabilities,” Nucl. Phys. A635, 231–256 (1998)

  54. [54]

    Further ex- plorations of Skyrme-Hartree-Fock-Bogoliubov mass for- mulas. XI. Stabilizing neutron stars against a ferromag- netic collapse,

    N. Chamel, S. Goriely, and J. M. Pearson, “Further ex- plorations of Skyrme-Hartree-Fock-Bogoliubov mass for- mulas. XI. Stabilizing neutron stars against a ferromag- netic collapse,” Phys. Rev. C80, 065804 (2009)

  55. [55]

    Further ex- plorations of Skyrme-Hartree-Fock-Bogoliubov mass for- mulas. XIII. The 2012 atomic mass evaluation and the symmetry coefficient,

    S. Goriely, N. Chamel, and J. M. Pearson, “Further ex- plorations of Skyrme-Hartree-Fock-Bogoliubov mass for- mulas. XIII. The 2012 atomic mass evaluation and the symmetry coefficient,” Phys. Rev. C88, 024308 (2013)

  56. [56]

    Entrainment effects in neutron-proton mixtures within the nuclear energy- density functional theory: Low-temperature limit,

    N. Chamel and V. Allard, “Entrainment effects in neutron-proton mixtures within the nuclear energy- density functional theory: Low-temperature limit,” Phys. Rev. C100, 065801 (2019)

  57. [57]

    Entrainment effects in neutron-proton mixtures within the nuclear energy- density functional theory. II. Finite temperatures and ar- bitrary currents,

    V. Allard and N. Chamel, “Entrainment effects in neutron-proton mixtures within the nuclear energy- density functional theory. II. Finite temperatures and ar- bitrary currents,” Phys. Rev. C103, 025804 (2021)

  58. [58]

    Collective modes in a super- fluid neutron gas within the quasiparticle random-phase approximation,

    N. Martin and M. Urban, “Collective modes in a super- fluid neutron gas within the quasiparticle random-phase approximation,” Phys. Rev. C90, 065805 (2014)

  59. [59]

    Superfluid Dynamics in Neutron Star Crusts,

    C. J. Pethick, N. Chamel, and S. Reddy, “Superfluid Dynamics in Neutron Star Crusts,” Prog. Theor. Phys. Suppl.186, 9–16 (2010)

  60. [60]

    Entrainment coefficient and effective mass for conduction neutrons in neutron star crust. 2. Macroscopic treatment,

    B. Carter, N. Chamel, and P. Haensel, “Entrainment coefficient and effective mass for conduction neutrons in neutron star crust. 2. Macroscopic treatment,” Int. J. Mod. Phys. D15, 777–803 (2006)

  61. [61]

    High-throughput elec- tronic band structure calculations: Challenges and tools,

    W. Setyawan and S. Curtarolo, “High-throughput elec- tronic band structure calculations: Challenges and tools,” Comput. Mater. Sci.49, 299–312 (2010)

  62. [62]

    Ring and P

    P. Ring and P. Schuck,The Nuclear Many-Body Problem (Springer, 1980)

  63. [63]

    New Skyrme parametrizations to describe finite nuclei and neutron star matter with realistic effective masses,

    M. Duan and M. Urban, “New Skyrme parametrizations to describe finite nuclei and neutron star matter with realistic effective masses,” Phys. Rev. C110, 065806 (2024)

  64. [64]

    Uni- fied description of neutron superfluidity in the neutron- star crust with analogy to anisotropic multiband BCS superconductors,

    N. Chamel, S. Goriely, J. M. Pearson, and M. Onsi, “Uni- fied description of neutron superfluidity in the neutron- star crust with analogy to anisotropic multiband BCS superconductors,” Phys. Rev. C81, 045804 (2010)

  65. [65]

    Pairing in pure neutron matter,

    S. Ramanan and M. Urban, “Pairing in pure neutron matter,” Eur. Phys. J. Spec. Top.230, 567 (2021)

  66. [66]

    Superfluidity and Entrainment in Neutron-star Crusts,

    N. Chamel, J. Pearson, and S. Goriely, “Superfluidity and Entrainment in Neutron-star Crusts,” inElectromag- netic Radiation from Pulsars and Magnetars, ASP Conf. Ser., Vol. 466, edited by W. Lewandowski, O. Maron, and J. Kijak (2012) p. 203

  67. [67]

    Nuclear shapes in the inner crust of a neutron star,

    K. Oyamatsu, “Nuclear shapes in the inner crust of a neutron star,” Nucl. Phys. A561, 431–452 (1993)

  68. [68]

    Shell energies of non- spherical nuclei in the inner crust of a neutron star,

    K. Oyamatsu and M. Yamada, “Shell energies of non- spherical nuclei in the inner crust of a neutron star,” Nucl. Phys. A578, 181–203 (1994)

  69. [69]

    Low-energy collec- tive excitations in the neutron star inner crust,

    N. Chamel, D. Page, and S. Reddy, “Low-energy collec- tive excitations in the neutron star inner crust,” Phys. Rev. C87, 035803 (2013)

  70. [70]

    Long-wavelength phonons in the crystalline and pasta phases of neutron-star crusts,

    D. Durel and M. Urban, “Long-wavelength phonons in the crystalline and pasta phases of neutron-star crusts,” Phys. Rev. C97, 065805 (2018)

  71. [71]

    Broy- den’s method in nuclear structure calculations,

    A. Baran, A. Bulgac, M. M. Forbes, G. Hagen, W. Nazarewicz, N. Schunck, and M. V. Stoitsov, “Broy- den’s method in nuclear structure calculations,” Phys. Rev. C78, 014318 (2008)