We inspect the possibility that neutron star interiors are a mixture of ordinary matter and mirror dark matter. This is a scenario that can be naturally envisaged according to well studied accretion mechanisms, including the Bondi–Hoyle one. We show that the inclusion of mirror dark matter in neutron star models lowers the maximum neutron star mass for a given equation of state, and that it decreases the tidal deformability of a given neutron star. These general features imply that, given an equation of state, one can constrain the maximum viable amount of mirror dark matter in neutron stars in order to consistently fulfil existing maximum mass and tidal deformability constraints. Conversely, using tidal deformability measurements to rule out equations of state requires making assumptions on the amount of mirror dark matter contained in neutron stars. Finally, the presence of mirror dark matter also modifies the universal relation that links the tidal deformability of a neutron star to its compactness. Therefore, caution is mandatory when considering exotic models, such as the ones discussed in this paper.

我们检查中子星内部是普通物质和镜面暗物质混合的可能性。根据包括Bondi-Hoyle在内的经过充分研究的吸积机制，可以自然地设想这种情况。我们表明，对于给定的状态方程，在中子星模型中包含镜面暗物质会降低最大中子星质量，并且会降低给定中子星的潮汐变形能力。这些一般特征暗示，给定一个状态方程，可以限制中子星中镜面暗物质的最大可行量，以便始终如一地满足现有的最大质量和潮汐变形能力约束。反过来，使用潮汐可变形性测量结果来排除状态方程，需要对中子星中镜面暗物质的含量做出假设。最后，镜面暗物质的存在还改变了将中子星的潮汐变形能力与其紧凑性联系起来的普遍关系。因此，在考虑外来模型（例如本文中讨论的模型）时，必须谨慎行事。