Warm dense matter and cooling of supernovae remnants

Abstract

We study the thermal effects on the nuclear matter (NM) properties such as binding energy, incompressibility, free symmetry energy and its coefficients using NL3, G3 and IU-FSU parameter sets of relativistic mean-field models. These models being consistent with the properties of cold NM, have also been used to study the effect of temperature by incorporating the Fermi function. The critical temperature for the liquid-gas phase transition in the symmetric NM is found to be 14.60, 15.37 and 14.50 MeV for NL3, G3 and IU-FSU parameter sets respectively, which is in excellent agreement with previous theoretical and experimental studies. We inspect that the properties related to second differential coefficient of the binding energy and free symmetry energy at saturation density ( i.e. $$K_{0}(n,T)$$K0(n,T) and $$Q_{sym,0}$$Qsym,0 ) exhibit the contrary effects for NL3 and G3 parameters as the temperature increases. We find that the prediction of saturated curvature parameter ( $$K_{sym,0}$$Ksym,0 ) for G3 equation of state at finite temperature favour the combined analysis of $$K_{sym,0}$$Ksym,0 for the existence of massive pulsars, gravitational waves from GW170817 and NICER observations of PSR J0030+0451. Further, we investigate the cooling mechanism of newly born stars through neutrino emissivity controlled by direct Urca process and instate some interesting remarks about neutrino emissivity. We also deliberate the effect of temperature on the M-R profile of Proto-Neutron star.

Dark Matter Effects on the Compact Star Properties

“…The EOS of the NS is calculated with the effective field theory motivated relativistic mean-field (E-RMF) model, where the nucleons interact with each other by exchanging different mesons. The model Lagrangian was constructed by including the self and crosscouplings between the important mesons terms up to the fourth-order [59][60][61][62]. The leptons (electrons and muons) contribution are also taken into account to maintain both β-equilibrium and charge neutrality condition [63].…”

“…All the coupling constants, masses and fields of different mesons are already given in Refs. [60,61,64]. The m * n is the effective masses of the nucleons, which is written as…”

Impacts of dark matter on the $f$-mode oscillation of hyperon star

“…Hence, the Lagrangian of the system includes the interaction from mesons-nucleons, mesons-hyperons and their self and cross-couplings. The extended RMF (E-RMF) model include the possible significant interactions between mesons up to the fourth-order [25][26][27][64][65][66][67]. We also add the leptons (e − and µ − ) contribution to the E-RMF Lagrangian because they are required to maintain both β-equilibrium and charge neutrality conditions which provide stability to the NS.…”

“…We also add the leptons (e − and µ − ) contribution to the E-RMF Lagrangian because they are required to maintain both β-equilibrium and charge neutrality conditions which provide stability to the NS. Therefore, the E-RMF Lagrangian of the NS system is given as [26,27,46,66]…”

Crustal properties of a neutron star within an effective relativistic mean-field model

“…The effective Lagrangian is consistent with the underlying quantum chromodynamics (QCD) symmetries and contains infinite terms, and none can be dropped without the proper symmetry argument [28]. The E-RMF theory has been very successful in the last two decades and has been applied in various nuclear problems, which range from the properties of the nucleus to the structure of the neutron star [29][30][31][32].…”