Isospin symmetry breaking effects on the mass-radius relation of a cold, non-accreting neutron star are studied on the basis of two Skyrme Energy Density Functionals (EDFs). One functional contains isospin symmetry breaking terms other than those typically included in Skyrme EDFs while its counterpart is of standard form. Both functionals are based on the same fitting protocol except for the observables and pseudo-observables sensitive to the isospin symmetry breaking channel. The quality of those functionals is similar in the description of terrestrial observables but choosing either of them has a non-negligible effect on the mass-radius relation and tidal deformability of a neutron star. Further investigations are needed to clarify the effects of isospin symmetry breaking on these and other observables of neutron stars that are, and will become, available.

中文翻译：

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同位旋对称性破坏对中子星质量半径关系的影响

基于两个Skyrme能量密度泛函（EDF），研究了等位旋对称破裂对冷的，不积聚的中子星质量半径关系的影响。除Skyrme EDF中通常包含的那些术语外，其中一个函数包含同位旋对称性打破术语，而对等形式为标准形式。两种功能均基于相同的拟合协议，但对同位旋对称性断裂通道敏感的可观察物和拟可观察物除外。这些功能的质量在地面可观测物的描述中相似，但是选择其中任何一个对中子星的质量半径关系和潮汐可变形性都具有不可忽略的影响。需要做进一步的研究来弄清楚同位旋对称性破裂对中子星的这些和其他可观察到的中子星的影响。