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Second Law of Black Hole Mechanics for all 2d Dilaton Theories

Norbert Duechting·Thomas Strobl
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Abstract

It is shown that all generalized two--dimensional dilaton theories with arbitrary matter content (with a curvature independent coupling to gravity) do not only obey a first law of black hole mechanics (which follows from Wald's general considerations, if the entropy S is defined appropriately), but also a second law: δS \ge 0 provided only that the null energy condition holds and that, loosely speaking, for late times a stationary state is assumed. Also any two-dimensional f(R)--theory is covered. This generalizes a previous proof of Frolov [1] to a much wider class of theories.

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Norbert Duechting, Thomas Strobl. 2000-09-26. Second Law of Black Hole Mechanics for all 2d Dilaton Theories. https://doi.org/10.1103/physrevd.63.024021

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