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How are neutron star cores described today, do we use models of superfluidity/superconductivity for instance?

yau
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  • Just google "neutron star superfluidity" http://www.astro.ulb.ac.be/~chamel/hydro_ns.html – anna v Apr 24 '15 at 11:06
  • The rapid cooling of a neutron star core is not explainable solely by superfluidity. Superconductivity also plays a role. But high temperatures and densities of neutron stars mean that "...particles are extremely closely packed and so act via the strong nuclear force, whereas on Earth superfluidity and superconductivity are mediated by the fundamentally different, and much weaker, electromagnetic force…" - http://physicsworld.com/cws/article/news/2011/mar/02/neutron-star-has-superfluid-core – Ernie Apr 24 '15 at 12:03
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    Insights into the physics of neutron star interiors from pulsar glitches: It seems that glitches are considered to be quite convincing evidence (probably more than cooling) for the presence of superfluid neutrons in the interior (probably the inner crust). Related: https://physics.stackexchange.com/q/278405/226902 – Quillo Sep 23 '23 at 14:47

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The "core" of a neutron star is of debatable composition and is dependent on the highly uncertain equation of state of matter compressed to $10^{18}$ kg/m$^3$.

It is possible that the core consists almost entirely of a solid neutron lattice with some protons that possibly form a superfluid.

Other possibilities include new mesonic (pions or kaons) or hadronic (hyperons) phases of matter, that would soften the equation of state. At even higher densities it is possible that quark matter becomes feasible.

The extent of superfluidity in the core is unknown. There could be both superfluid protons and neutrons.

Observational evidence, based on the recent discovery of 2 solar mass neutron stars and the relatively slow cooling of some neutron stars suggests mesons are unlikely. Other analysis of pulsar glitches and the very rapid cooling of the Cas A neutron star suggest superfluid neutrons do at least exist in the "inner crust" of neutron stars.

ProfRob
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