Revisiting Barrow's graduated inflationary universe: A warm perspective

It is presumed that thermal fluctuations present during inflationary epoch can make inflaton scalar field to interact with other fields resulting in the existence of a thermal component during the inflationary period. The presence of this thermal component assists structure formation and reduces reheating dependence as in the contemporary inflationary paradigm. This is known as warm inflation. In 1990 J.D. Barrow [26] considered a scenario of inflation with matter field having a phenomenological equation of state of the type p + rho = gamma rho(lambda), gamma not equal 0 and lambda constant. He called such inflationary scenarios as graduated inflation. In this work we reconsider the above equation of state in a scenario of warm inflation. Our aim would be to investigate and understand whether such matter can also act as a viable candidate for warm inflation. (C) 2022 The Author(s). Published by Elsevier B.V.

Automated summary

Thermal fluctuations during the inflationary epoch can result in the presence of a thermal component, known as warm inflation. It has been found that matter with specific equation of state can also act as a candidate for warm inflation.