Are Black Holes Springy?

Abstract

A (3+1)-dimensional asymptotically at Kerr black hole angular speed + can be used to de ne an e ective spring constant, k = m2 +. Its maximum value is the Schwarzschild surface gravity, k = , which rapidly weakens as the black hole spins down and the temperature increases. The Hawking temperature is expressed in terms of the spring constant: 2 T = 􀀀 k. Hooke's law, in the extremal limit, provides the force F = 1=4, which is consistent with the conjecture of maximum force in general relativity.