A new statistical method for the structure of the inner crust of neutron stars

Abstract

We investigated the structure of the low density regions of the inner crust of neutron stars using the Hartree-Fock-Bogoliubov (HFB) model to predict the proton content $Z$ of the nuclear clusters and, together with the lattice spacing, the proton content of the crust as a function of the total baryonic density ${\rho }_b$. The exploration of the energy surface in the $(Z,{\rho }_b)$ configuration space and the search for the local minima require thousands of calculations. Each of them implies an HFB calculation in a box with a large number of particles, thus making the whole process very demanding. In this work, we apply a statistical model based on a Gaussian Process Emulator that makes the exploration of the energy surface ten times faster. We also present a novel treatment of the HFB equations that leads to an uncertainty on the total energy of $\approx 4$ keV per particle. Such a high precision is necessary to distinguish neighbour configurations around the energy minima.

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Cited by in corpus (10)

• Impact of statistical uncertainties on the composition of the outer crust of a neutron star
• Analytical determination of the structure and nuclear abundances of the outer crust of a cold nonaccreted neutron star
• Systematic analysis of inner crust composition using the extended Thomas-Fermi approximation with pairing correlations
• Comparison between the Thomas-Fermi and Hartree-Fock-Bogoliubov Methods in the Inner Crust of a Neutron Star: The Role of Pairing Correlations
• The proto-neutron star inner crust in the liquid phase
• Building Surrogate Models of Nuclear Density Functional Theory with Gaussian Processesand Autoencoders
• Time-dependent nuclear energy-density functional theory toolkit for neutron star crust: Dynamics of a nucleus in a neutron superfluid
• Role of neutron pairing with density-gradient dependence in the semi-microscopic treatment of the inner crust of neutron stars
• How accurately can the Extended Thomas-Fermi method describe the inner crust of a neutron star?
• Pressure and chemical potentials in the inner crust of a cold neutron star within Hartree-Fock and extended Thomas-Fermi methods