Interpreting high-energy, astrophysical phenomena, such as supernova explosions or neutron-star collisions, requires a robust understanding of matter at supranuclear densities. However, our knowledge about dense matter explored in the cores of neutron stars remains limited. Fortunately, dense matter is not probed only in astrophysical observations, but also in terrestrial heavy-ion collision experiments. Here we use Bayesian inference to combine data from astrophysical multi-messenger observations of neutron stars^{1,2,3,4,5,6,7,8,9} and from heavy-ion collisions of gold nuclei at relativistic energies^10,11 with microscopic nuclear theory calculations^{12,13,14,15,16,17} to improve our understanding of dense matter. We find that the inclusion of heavy-ion collision data indicates an increase in the pressure in dense matter relative to previous analyses, shifting neutron-star radii towards larger values, consistent with recent observations by the Neutron Star Interior Composition Explorer mission^5,6,7,8,¹⁸. Our findings show that constraints from heavy-ion collision experiments show a remarkable consistency with multi-messenger observations and provide complementary information on nuclear matter at intermediate densities. This work combines nuclear theory, nuclear experiment and astrophysical observations, and shows how joint analyses can shed light on the properties of neutron-rich supranuclear matter over the density range probed in neutron stars.

解释高能天体物理现象，如超新星爆炸或中子星碰撞，需要对超核密度物质有深入的了解。然而，我们对在中子星核心探索的致密物质的了解仍然有限。幸运的是，致密物质不仅在天体物理观测中得到探索，而且在陆地重离子碰撞实验中也得到了探索。在这里，我们使用贝叶斯推断将来自中子星^{1、2、3、4、5、6、7、8、9的天体物理多信使观测数据和相对论能量10，11}的金核重离子碰撞的数据与微观核理论计算^{12,13,14,15,16,17}以提高我们对致密物质的理解。我们发现，包含重离子碰撞数据表明，与之前的分析相比，致密物质的压力增加，将中子星半径向更大的值移动，这与中子星内部成分探索者任务^{5,6 最近的观察结果一致， 7,8} , ¹⁸。我们的研究结果表明，重离子碰撞实验的约束与多信使观测具有显着的一致性，并提供了关于中等密度核物质的补充信息。这项工作结合了核理论、核实验和天体物理观测，并展示了联合分析如何揭示在中子星探测的密度范围内富含中子的超核物质的特性。