Generalized skyrmion crystals with applications to neutron stars

Abstract

In this article we study properties of isospin asymmetric nuclear matter in the generalized Skyrme model. This is achieved by canonically quantizing the isospin collective degrees of freedom of the recently found multi-wall skyrmion crystal. We obtain, for the first time, an equation of state from the Skyrme model which interpolates between infinite isospin asymmetric nuclear matter and finite isospin symmetric atomic nuclei. This enables us to describe neutron stars with crusts within the Skyrme framework. Furthermore, we observe that the symmetry energy tends to a constant value at zero density, which can be identified with the asymmetry coefficient in the semi-empirical mass formula for atomic nuclei. The symmetry energy also reveals a cusp in its structure below the nuclear saturation point $n_0$ at $n_{\ast }\sim 3n_0/4$. This cusp density point $n_{\ast }$ can be interpreted as the nuclear density whereby the infinite crystalline multi-wall configuration undergoes a phase transition to a finite isolated multi-wall configuration. Both of these observations are observed to be generic features of skyrmion crystals that tend asymptotically to somewhat isolated skyrmion configurations in the zero density limit. We find that the resulting neutron stars from our study agree quite well with recent NICER/LIGO observational data.

23 pages, 7 figures

References in corpus (23)

• Progress in Constraining Nuclear Symmetry Energy Using Neutron Star Observables Since GW170817
• Symmetry energy of dilute warm nuclear matter
• Skyrmions, instantons and holography
• Experimental determination of the symmetry energy of a low density nuclear gas
• Skyrmions and the alpha-particle model of nuclei
• Light Nuclei of Even Mass Number in the Skyrme Model
• Skyrmions with massive pions
• Half-Skyrmions, Tensor Forces and Symmetry Energy in Cold Dense Matter
• Light Nuclei as Quantized Skyrmions
• A dynamical $\alpha$-cluster model of ${}^{16}$O
• States of Carbon-12 in the Skyrme Model
• BPS Skyrmions as neutron stars
• Crystals of superconducting Baryonic tubes in the low energy limit of QCD at finite density
• Thermodynamics of the BPS Skyrme model
• Generalized Skyrme model with the loosely bound potential
• Scaling Identities for Solitons beyond Derrick's Theorem
• The Inhomogeneous Phase of Dense Skyrmion Matter
• Baryon chemical potential and in-medium properties of BPS skyrmions
• Oxygen-16 Spectrum from Tetrahedral Vibrations and their Rotational Excitations
• Skyrme crystals, nuclear matter and compact stars
• Skyrme crystals with massive pions
• Effect of Coulomb energy on Skyrmions
• Generalized Skyrme Crystals

Cited by in corpus (5)

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• Isospin asymmetry and neutron stars in V-QCD
• Domain Wall Networks as Skyrmion Crystals in Chiral Magnets
• Baby skyrmion crystals stabilized by vector mesons
• Compressibility of dense nuclear matter in the $\rho$-meson variant of the Skyrme model