Black Holes: Absolute Rigidity ⚡ экспресс
According to classical general relativity, the tidal Love numbers for Kerr black holes in vacuum are zero, but can become nonzero in the presence of exotic matter or in alternative theories of gravity. The gravitational-wave event GW250114, recorded with an unprecedentedly high signal-to-noise ratio, was used to test this prediction. The data analysis supports the binary black hole hypothesis and places an upper limit at 90% confidence on the effective tidal deformability: \tilde{\Lambda} < 34.8. This implies that any environment around the black holes contributes less than ~7×10⁻³ of their mass, ruling out several boson star models. These constraints represent the strongest observational evidence for a vanishingly small tidal deformability of black holes and are fully consistent with zero Love numbers for Kerr black holes.
If two steel balls circle each other, their mutual attraction is powerless to change each other's shape. A water ball, on the contrary, would stretch out like a droplet. A fresh analysis of gravitational waves from the merger of black holes GW250114 — the cleanest ever recorded — shows: black holes are like perfectly rigid steel balls. They do not deform, no matter how hard the neighbor pulls.
The new result, obtained after processing the signal from LIGO and Virgo detectors, sets a record bar: tidal forces caused by spacetime curvature and billions of times stronger than those the Moon exerts on Earth's oceans left not a hint of stretching. The allowable deformation is so minuscule that if a black hole were the size of a soccer ball, its point of no return (event horizon) would shift by less than the thickness of a proton. This rules out exotic hypotheses like boson stars — quantum lumps without a solid shell. Weiss and Thorne once searched for such deviations, but nature appears to prefer simplicity.
🎯 If a black hole the size of a soccer ball were subjected to tidal forces, the allowable deformation of its horizon would be less than the thickness of a proton.