ON THE PHASE-SPACE VOLUME OF PRIMORDIAL COSMOLOGICAL PERTURBATIONS

We show how to determine the typical phase-space volume, Gamma, for pr imordial gravitational waves produced during an inflationary stage, wh ich is invariant under squeezing. An expression for Gamma is found in the long wavelength regime. The quasi-classical entropy of a pure vacu um initial state defined as the logarithm of Gamma module a constant r emains zero in spite of the generation of fluctuations (creation of re al gravitons).