{
  "id": "1709.02186",
  "version": "v1",
  "published": "2017-09-07T11:40:05.000Z",
  "updated": "2017-09-07T11:40:05.000Z",
  "title": "Reinvestigation of the electron fraction and electron Fermi energy of neutron star",
  "authors": [
    "Zhi-Fu Gao",
    "Xiangdong Li",
    "Hao Shan",
    "Wei Wang",
    "Na Wang"
  ],
  "comment": "3 figures, 3 tables , and We welcome any comment you might have about the content, To be published in Astron. Nachr",
  "categories": [
    "astro-ph.HE"
  ],
  "abstract": "In this work, we reinvestigate the electron fraction $Y_{e}$ and electron Fermi energy $E_{F}(e)$ of neutron stars, based on our previous work of Li et al.(2016), in which we firstly deduced a special solution to $E_{F}(e)$, and then obtained several useful analytical formulae for $Y_{\\rm e}$ and matter density $\\rho$ within classical models and the relativistic mean field(RMF) theory using numerically fitting. The advantages of this work include the following aspects:(1) The linear functions are substituted for the nonlinear exponential functions used in the previous work. This method may be more simple, and closer to realistic equation of state\\,(EoS) of a neutron star(NS), because there are linear or quasi-linear relationships between number fractions of leptons and matter density, which can be seen by solving NS EoS; (2)we introduce a dimensionless variable $\\varrho$\\,($\\varrho=\\rho/\\rho_0$, $\\rho_{0}$ is the standard saturated nuclear density), which greatly reduces the scope of the fitting coefficients;(3)we present numerical errors including absolute and relative deviations between the data and fit. By numerically simulating, we have obtained several analytical formulae for $Y_{e}$ and $\\rho$ for both APR98 and RMF models. Combining these analytical formulae with the special solution, we can calculate the value of $E_{\\rm F}(e)$ for any given matter density. Since $Y_e$ and $E_{ F}(e)$ are important in assessing cooling rate of a NS and the possibility of kaon/pion condensation in the NS interior, this study could be useful in the future study on the thermal evolution of a NS.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2017-09-07T11:40:05.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "electron fermi energy",
      "neutron star",
      "electron fraction",
      "matter density",
      "analytical formulae"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}