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Black hole polarization and new entropy bounds

Jacob D. Bekenstein·Avraham E. Mayo
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Abstract

Zaslavskii has suggested how to tighten Bekenstein's bound on entropy when the object is electrically charged. Recently Hod has provided a second tighter version of the bound applicable when the object is rotating. Here we derive Zaslavskii's optimized bound by considering the accretion of an ordinary charged object by a black hole. The force originating from the polarization of the black hole by a nearby charge is central to the derivation of the bound from the generalized second law. We also conjecture an entropy bound for charged rotating objects, a synthesis of Zaslavskii's and Hod's. On the basis of the no hair principle for black holes, we show that this last bound cannot be tightened further in a generic way by knowledge of ``global'' conserved charges, e.g., baryon number, which may be borne by the object.

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Jacob D. Bekenstein, Avraham E. Mayo. 1999-03-14. Black hole polarization and new entropy bounds. https://doi.org/10.1103/physrevd.61.024022

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