Mass density perturbations from inflation with thermal dissipation - art. no. 083503

We study the power spectrum of the mass density perturbations in an inflati on scenario that includes thermal dissipation. We show that the condition o n which the thermal fluctuations dominate the primordial density perturbati ons can easily be realized even for weak dissipation. i.e., the rate of dis sipation is less than the Hubble expansion. We find that our spectrum of pr imordial density perturbations follows a power law behavior, and exhibits a "thermodynamical" feature-the amplitude and power index of thr spectrum de pend mainly on the thermodynamical variable M, the inflation energy scale. Comparing this result with the observed temperature fluctuations of the cos mic microwave background, we find that both amplitude and index of the powe r spectrum can be fairly well fitted if M similar to 10(15)-10(16) GeV. [S0 556-2821(99)03806-0].