1. Universal upper bound on the entropy-to-energy ratio for bounded systems
2. Statistical Physics;Landau,1969
3. Black Holes and Entropy
4. Particle creation by black holes
5. It is worth emphasizing that there are several ways to define the effective size of a black-hole system. In particular, the black-hole spacetime is characterized by an infinite throat in the extremal limit. This infinite throat may suggest that the effective size of the black-hole system diverges in the extremal (zero-temperature) limit.