We have computed the properties of compact objects like neutron stars based on equation of state (EOS) deduced from a core–envelope model of superdense stars. Such superdense stars have been studied by solving Einstein’s equation based on pseudo-spheroidal and spherically symmetric spacetime geometry. The computed star properties are compared with those obtained based on nuclear matter EOSs. From the mass–radius (M–R) relationship obtained here, we are able to classify compact stars in three categories: (i) highly compact self-bound stars that represents exotic matter compositions with radius lying below 9km; (ii) normal neutron stars with radius between 9 to 12km and (iii) soft matter neutron stars having radius lying between 12 to 20km. Other properties such as Keplerian frequency, surface gravity and surface gravitational redshift are also computed for all the three types. This work would be useful for the study of highly compact neutron like stars having exotic matter compositions.

中文翻译：

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基于几何推导出的状态方程的不同类型的致密星

我们已经根据从超致密恒星的核心-包络模型推导出的状态方程 (EOS) 计算了像中子星这样的致密物体的属性。已经通过求解基于伪球体和球对称时空几何的爱因斯坦方程来研究这种超密集恒星。计算的恒星属性与基于核物质 EOS 获得的属性进行比较。从质量半径（米–R) 关系，我们能够将致密恒星分为三类：（i）高度致密的自束缚恒星，代表半径低于 9 的奇异物质成分公里；(ii) 半径在 9 到 12 之间的普通中子星km 和 (iii) 半径在 12 到 20 之间的软物质中子星公里。还计算了所有三种类型的其他属性，例如开普勒频率、表面引力和表面引力红移。这项工作将有助于研究具有奇异物质成分的高度致密的中子类恒星。