Binary Love Relations

Understand

When in a tight binary, the mutual tidal deformations of neutron stars imprint onto observables, encoding information about their internal structure at supranuclear densities and gravity in the extreme-gravity regime.

• Gravitational wave observations of their late binary inspiral may serve as a tool to extract the individual tidal deformabilities, but this is made difficult by degeneracies between them in the gravitational wave model.
• We here resolve this problem by discovering approximately universal relations between dimensionless combinations of the individual tidal deformabilities.
• We show that these relations break degeneracies in the gravitational wave model, allowing for the accurate extraction of both deformabilities.