Within the covariant density functional theory of nuclear matter we build equations of state of ∆-admixed compact stars. Uncertainties in the interaction of ∆(1232) resonance states with nuclear matter, due to lack of experimental data, are accounted for by varying the coupling constants to scalar and vector mesonic fields. We find that, over a wide range of the parameter space allowed by nuclear physics experiments and astrophysical observations, cold catalyzed star matter exhibits a first order phase transition which persists also at finite temperature and out of β-equilibrium in the neutrino-transparent matter. Compact stars featuring such a phase transition in the outer core have small radii and, implicitly, tidal deformabilities. The parameter space is identified where simultaneously ∆-admixed compact stars obey the astrophysical constraint on maximum mass and allow for dUrca processes, which is otherwise forbidden.

中文翻译：

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Δ-混合中子星：旋节线不稳定性和 dUrca 过程

在核物质的协变密度泛函理论中，我们建立了 ∆ 混合致密星的状态方程。由于缺乏实验数据，∆(1232) 共振态与核物质相互作用的不确定性是通过改变与标量和矢量介子场的耦合常数来解释的。我们发现，在核物理实验和天体物理观测允许的广泛参数空间内，冷催化的恒星物质表现出一阶相变，这种相变也在有限温度下持续存在，并且在中微子透明物质中超出 β 平衡。在外核中具有这种相变特征的致密星具有很小的半径，并且隐含地具有潮汐变形能力。