Properties of neutron stars with hyperons in the relativistic mean field theory

Abstract

Abstract.We study the equation of state (EOS) of the dense matter in the core of neutron stars with hyperons included and the star structure based on the Zimanyi & Moszkowski (ZM) model in the relativistic mean-field theory with a set of recent satisfactory parameters. The relation between hyperon abundances and baryon number densities is calculated and the distribution of baryons in the core of a typical neutron star of 1.4 M is presented. Our results satisfy the requirements from observations of the mass of binary radio pulsars, and the ratio, Ic/Itot, of the crustal momentum of inertia to the total one. The actual surface thermal radiation detected seems to indicate that baryons in the core of neutron stars should pair to form a superfluid phase, if hyperons appear in the core of neutron stars.

Impact of hyperons and antikaons in an extended relativistic mean-field description of neutron stars

“…In our calculations we treat these parameters in a way similar to works in Refs. [13,34]. The density profiles of n, p, , and − are almost the same at high density, except with IUFSU, where the contribution from n is much higher.…”

“…Neutron stars were studied within RMF models with the inclusion of hyperons [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19], the antikaon K − [20][21][22][23][24][25][26][27], the antikaons K − andK 0 [28][29][30][31], and both hyperons and antikaons [32][33][34][35][36]. Recently, we have studied the role of antikaons [23,37] in the presence of higher order couplings of the extended RMF models.…”

Neutron Stars with Hyperons subject to Strong Magnetic Field

“…In this work we consider a hadronic neutron star composed by hyperons submitted to a strong magnetic field. We see that while the presence of hyperons reduce the maximum mass by softening the equation the state (EoS) [1,11,[28][29][30][31], the presence of a density-dependent magnetic field tends to increase the maximum mass stiffening the EoS [13,17,20]. Our study shows also that although the influence of a strong magnetic field stiffener the EoS, a hyperonic magnetar still has a softer EoS compared with a common atomic stars.…”

“…Moreover, denser stars can support stronger magnetic fields in their center (B c ) as a consequence of eq. (29). A curious fact is that while the radius of the hyperonic star with the maximum mass decreases for strong magnetic fields, in the atomic stars the radius grows with the increase of B.…”