Quantum corrections to tidal Love number for Schwarzschild black holes.

A sum rule for tidal Love number is derived from quantum field theory computations, which relates tidal susceptibility of a spinless body to transition rates of its single graviton emission processes. An analogous sum rule for electromagnetism is given as an example, which is substantiated by comparing to the solved problem of the hydrogen atom. Using the sum rule, the Love number of Schwarzschild black holes in general relativity, which is known to classically vanish, is shown to have non-vanishing finite quantum corrections due to Hawking radiation.