The gravitational waves emitted by neutron star binaries probe the physics of matter at supranuclear densities. During the late inspiral, tidal deformations raised on each star by the gravitational field of its companion depend crucially on the star’s internal properties. The misalignment of a star’s tidal bulge with its companion’s gravitational field encodes the strength of internal dissipative processes, which imprint onto the phase of the gravitational waves emitted. Here, we analyse gravitational wave data from the GW170817 (binary neutron star) event detected by LIGO and Virgo and find a constraint on the dissipative tidal deformability of a neutron star. From this constraint, assuming a temperature profile for each star in the binary, we obtain an order of magnitude bound on the averaged bulk (ζ) and shear (η) viscosity of each star during the inspiral: ζ ≲ 10³¹ g cm⁻¹ s⁻¹ and η ≲ 10²⁸ g cm⁻¹ s⁻¹. We forecast that these bounds could be improved by two orders of magnitude with third-generation detectors, like Cosmic Explorer, using inspiral data. These constraints already inform nuclear physics models and motivate further theoretical work to better understand the interplay between viscosity and temperature in the late inspiral of neutron stars.

中子星双星发出的引力波探测超核密度物质的物理特性。在螺旋运动后期，每颗恒星由其伴星的引力场引起的潮汐变形在很大程度上取决于恒星的内部特性。恒星的潮汐隆起与其伴星引力场的错位编码了内部耗散过程的强度，该过程会印记在所发射的引力波的相位上。在这里，我们分析了 LIGO 和 Virgo 检测到的 GW170817（双中子星）事件的引力波数据，并找到了中子星耗散潮汐变形能力的约束。根据这个约束，假设双星中每颗恒星的温度分布，我们获得了每颗恒星在螺旋过程中的平均体积 (ze) 和剪切 (η) 粘度的一个数量级： ze ≲ 10 ³¹ s ⁻¹ 且 η ≲ 10 ²⁸ g cm ⁻¹ s ⁻¹ 。我们预测，使用启发数据的第三代探测器（例如宇宙探索者）可以将这些界限提高两个数量级。这些限制已经为核物理模型提供了信息，并激发了进一步的理论工作，以更好地理解中子星晚期螺旋中粘度和温度之间的相互作用。