Klein-Gordon thermal equation for a Planck gas

In this paper the quantum hyperbolic equation formulated in our earlier pap er [Found. Phys. Lett. 10, 599 (1997)] is applied to the study of the propa gation of the initial thermal state of the universe. It is shown that the p ropagation depends on the barrier height. The Planck wall potential is intr oduced, V-P = (h) over bar/8t(P) = 1.125 10(18) GeV, where t(P) is a Planck time. For the barrier height V < V-P, the master thermal equation is the m odified telegrapher's equation, and for barrier height V > V-P the master e quation is the Klein-Gordon equation. The solutions of both type equations for Cauchy boundary conditions are discussed.