Density perturbations of thermal origin during inflation

Wolung Lee*, Li Zhi Fang

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

14 Citations (Scopus)


We study thermally induced density perturbations during inflation. This scenario is characterized by two thermodynamical conditions: (1) The primordial perturbations originate in the epoch when the inflationary universe contains a thermalized heat bath. (2) The perturbations of the inflationary scalar field are given by the fluctuation-dissipation relation. We show that the spectrum of the primordial perturbations is of power law, but tilted, and there is a relation between the amplitude and the index of the power spectrum. Aside from the mass scale of the inflation, the amplitude-index relation does not depend on other parameters like g-factor. These results are found to be well consistent with observations of the temperature fluctuations of cosmic microwave background if the mass scale of the inflation is about 1015 GeV. Instead of the purely adiabatic case, the consequent density perturbation is an admixture of adiabatic and isocurvature one. Therefore, the detection of super-Hubble suppression of the spectrum would be effective for further discrimination between the thermally originated models and others.

Original languageEnglish
Pages (from-to)305-322
Number of pages18
JournalInternational Journal of Modern Physics D
Issue number3
Publication statusPublished - 1997 Jun
Externally publishedYes

ASJC Scopus subject areas

  • Mathematical Physics
  • Astronomy and Astrophysics
  • Space and Planetary Science


Dive into the research topics of 'Density perturbations of thermal origin during inflation'. Together they form a unique fingerprint.

Cite this