INITIAL CONDITION FOR THE MINIMAL ISOCURVATURE SCENARIO

We derive a proper expression for the power spectrum of baryon-number fluctuations arising from decay of a heavy Majorana lepton with space-dependent CP violation due to a spatially varying Majoron field. The spectrum is explicitly calculated in a power-law inflation model and found to be almost scale invariant on small scales and white noise on large scales. Under reasonable assumptions, we present a natural particle-physics model which provides an appropriate initial condition for the minimal isocurvature scenario of large-scale structure formation.