Temperature-dependent oscillation modes in rotating superfluid neutron stars

Dommes, Vasiliy A.; Kantor, E. M.; Gusakov, M. E.

doi:10.1093/mnras/sty2841

Cited by 10 publications

(19 citation statements)

References 32 publications

(50 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We have found that in thermodynamic equilibrium the quasi-particle current is locked to the entropy current, or, in other words, the entropy is transported by the excitations, in agreement with the Landau theory of superfluidity [40], see equations (8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24), and of Khalatnikov [31]. The two equilibrium conditions (59) and (60) are also in accordance with the derivation of the thermodynamics of a generic multifluid presented in [10].…”

Section: A Equilibration Dynamics and Equilibrium Conditionssupporting

confidence: 74%

“…In the absence of dissipation, it has been shown [10] that the phenomenological multifluid of Carter and Khalatnikov is an exact reformulation of the more fundamental models for a relativistic superfluid of Son [11] and Gusakov [12]. Moreover, Carter's multifluid is a convenient formalism to describe neutron stars [13,14], notably their structure [15,16], oscillations [17][18][19] and the phenomenon of pulsar glitches [20][21][22][23].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Extending Israel and Stewart hydrodynamics to relativistic superfluids via Carter's multifluid approach

Gavassino,

Antonelli,

Haskell

2021

Preprint

View full text Add to dashboard Cite

We construct a relativistic model for bulk viscosity and heat conduction in a superfluid. Building on the principles of Unified Extended Irreversible Thermodynamics, the model is derived from Carter's multifluid approach for a theory with three currents, where the quasi-particle current is an independent hydrodynamic degree of freedom. For small deviations from local thermodynamic equilibrium, the model reduces to an extension of the Israel-Stewart theory to superfluid systems. It can, therefore, be made hyperbolic, causal and stable if the microscopic input is accurate. The non-dissipative limit of the model is the relativistic two-fluid model of Carter, Khalatnikov and Gusakov. The Newtonian limit of the model is an Extended-Irreversible-Thermodynamic extension of Landau's two-fluid model. The model predicts the existence of four bulk viscosity coefficients and accounts for their microscopic origin, providing their exact formulas in terms of the quasi-particle creation rate. Furthermore, when fast oscillations of small amplitude around the equilibrium are considered, the relaxation-time term in the telegraph-type equations for the bulk viscosities accounts directly for their expected dependence on the frequency.

show abstract

Section: A Equilibration Dynamics and Equilibrium Conditionssupporting

confidence: 74%

Section: Introductionmentioning

confidence: 99%

Extending Israel and Stewart hydrodynamics to relativistic superfluids via Carter's multifluid approach

Gavassino,

Antonelli,

Haskell

2021

Preprint

View full text Add to dashboard Cite

show abstract

“…Although observed neutron stars are usually cold, meaning that their internal temperature T is much lower than the Fermi temperatures T Fq , thermal effects may still be significant for the superfluid dynamics since the associated critical temperatures T cq are typically much lower than T Fq . In particular, it has been recently shown that the temperature dependence of the entrainment matrix may have implications for neutron-star oscillations [11,12].…”

Section: Introductionmentioning

confidence: 99%

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

Allard

Chamel

2021

Phys. Rev. C

View full text Add to dashboard Cite

Mutual entrainment effects in hot neutron-proton superfluid mixtures are studied in the framework of the self-consistent nuclear energy-density functional theory. The local mass currents in homogeneous or inhomogeneous nuclear systems, which we derive from the time-dependent Hartree-Fock-Bogoliubov equations at finite temperatures, are shown to have the same formal expression as the ones we found earlier in the absence of pairing at zero temperature. Analytical expressions for the entrainment matrix are obtained for application to superfluid neutron-star cores. Results are compared to those obtained earlier using Landau's theory. Our formulas, valid for arbitrary temperatures and currents, are applicable to various types of functionals including the Brussels-Montreal series for which unified equations of state have been already calculated, thus, laying the ground for a fully consistent microscopic description of superfluid neutron stars.

show abstract

“…To put it on a solid ground and to prove that the avoided-crossings of the most unstable r-mode with SF modes take place in the parameter range relevant to NSs in LMXBs, one has to calculate the r-mode spectrum for SF NSs at finite temperatures. This goal had been reached in the previous studies [18,19] under certain assumptions. Namely, Ref.…”

Section: Introductionmentioning

confidence: 95%

“…[18] calculated the r-mode spectrum for a SF neutron star stratified by muons, neglecting the entrainment between neutrons and protons (i.e., assuming that motion of one particle species does not induce particle current of another species). Subsequent work [19] accounted for the entrainment effect, but assumed that NS core consists of neutrons, protons, and electrons only. Here we calculate the spectrum allowing for both muons and entrainment in the core, and show that together they change the spectrum qualitatively.…”

Section: Introductionmentioning

confidence: 99%

Resonance suppression of the r-mode instability in superfluid neutron stars: Accounting for muons and entrainment

Kantor,

Gusakov,

Dommes

2021

Preprint

View full text Add to dashboard Cite

We calculate the finite-temperature r-mode spectrum of a superfluid neutron star accounting for both muons in the core and the entrainment between neutrons and protons. We show that the standard perturbation scheme, considering the rotation rate as an expansion parameter, breaks down in this case. We develop an original perturbation scheme which circumvents this problem by treating both the perturbations due to rotation and (weak) entrainment simultaneously. Applying this scheme, we propose a simple method for calculating the superfluid r-mode eigenfrequency in the limit of vanishing rotation rate. We also calculate the r-mode spectrum at finite rotation rate for realistic microphysics input (adopting, however, the Newtonian framework and Cowling approximation when considering perturbed oscillation equations) and show that the normal r-mode exhibits resonances with superfluid r-modes at certain values of temperatures and rotation frequencies in the parameter range relevant to neutron stars in low-mass X-ray binaries (LMXBs). This turns the recently suggested phenomenological model of resonance r-mode stabilization into a quantitative theory, capable of explaining observations. A strong dependence of resonance rotation rates and temperatures on the neutron superfluidity model allows us to constrain the latter by confronting our calculations with the observations of neutron stars in LMXBs.

show abstract

Temperature-dependent oscillation modes in rotating superfluid neutron stars

Cited by 10 publications

References 32 publications

Extending Israel and Stewart hydrodynamics to relativistic superfluids via Carter's multifluid approach

Extending Israel and Stewart hydrodynamics to relativistic superfluids via Carter's multifluid approach

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

Resonance suppression of the r-mode instability in superfluid neutron stars: Accounting for muons and entrainment

Contact Info

Product

Resources

About