Abstract
We present evidence that quantum Zeno effect, otherwise working only for microscopic systems, may also work for large black holes (BH's). The expectation that a BH geometry should behave classically at time intervals larger than the Planck time tPl indicates that the quantum process of measurement of classical degrees of freedom takes time of the order of tPl. Since BH has only a few classical degrees of freedom, such a fast measurement makes a macroscopic BH strongly susceptible to the quantum Zeno effect, which repeatedly collapses the quantum state to the initial one, the state before the creation of Hawking quanta. By this mechanism, Hawking radiation from a BH of mass M is strongly suppressed by a factor of the order of mPl/M.
Highlights
S ∼ A/l2Pl ∼ R2/l2Pl ∼ M2/m2Pl, (1)Fast-repeated measurements of an unstable quantum system may prevent its decay and stabilize it, by the mechanism known as quantum Zeno effect [1,2,3,4]
As for most other quantum phenomena, it is typical for quantum Zeno effect that it works for microscopic systems, not for the macroscopic ones
BH geometry of a large black hole obeys classical laws, while classicality is a consequence of fast measurement of classical properties, due to which a quantum superposition collapses to a state in which classical observables have definite values
Summary
Fast-repeated measurements of an unstable quantum system may prevent its decay and stabilize it, by the mechanism known as quantum Zeno effect [1,2,3,4]. The entropy (1) is very large for macroscopic black holes with M mPl, so at first sight it may seem that quantum Zeno effect cannot work for macroscopic black holes Most of these degrees of freedom are irrelevant for Hawking radiation. The interaction with a larger number of environment degrees implies a faster process of decoherence and a faster process of measurement [2,6], which strongly suggests that the measurement of the relevant BH degrees of freedom is much faster than for ordinary atoms In this way, the remarkable BH property of being both macroscopic (by size and mass) and microscopic (by the small number of classical degrees of freedom) makes black holes extremely susceptible to the quantum Zeno effect. In the absence of a complete quantum theory of gravity, a lot of quantitative arguments will rely on the order-of-magnitude estimates
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
