  The interplay of black hole and cosmological horizons introduces distinctive
thermodynamic behavior for deSitter black holes, including well-known upper
bounds for the mass and entropy. We point to a new such feature, a Schottky
peak in the heat capacity of Schwarzschild-deSitter (SdS) black holes. With
this behavior in mind, we explore statistical models for the underlying quantum
degrees of freedom of SdS holes. While a simple two-state spin model gives
Schottky behavior, in order to capture the non-equilibrium nature of the SdS
system we consider a system with a large number of non-interacting spins. We
examine to what extent constrained states of this system reproduce the
thermodynamic properties of the black hole. We also review results of a recent
study of particle production in SdS spacetimes in light of the Schottky anomaly
and our spin models.
