Warm inflation with non-comoving scalar field and radiation fluid

Abstract

We consider a warm inflationary scenario in which the two major fluid components of the early Universe, the scalar field and the radiation fluid, evolve with distinct four-velocities. This cosmological configuration is equivalent to a single anisotropic fluid, expanding with a four-velocity that is a combination of the two fluid four-velocities. Due to the presence of anisotropies the overall cosmological evolution is also anisotropic. We obtain the gravitational field equations of the non-comoving scalar field–radiation mixture for a Bianchi Type I geometry. By assuming the decay of the scalar field, accompanied by a corresponding radiation generation, we formulate the basic equations of the warm inflationary model in the presence of two non-comoving components. By adopting the slow-roll approximation the theoretical predictions of the warm inflationary scenario with non-comoving scalar field and radiation fluid are compared in detail with the observational data obtained by the Planck satellite in both weak dissipation and strong dissipation limits, and constraints on the free parameters of the model are obtained. The functional forms of the scalar field potentials compatible with the non-comoving nature of warm inflation are also obtained.

Recent Developments in Warm Inflation

“…Moreover, there are several papers in the literature which studied WI using some quasi-de Sitter form of scale factor, e.g., intermediate and logamediate inflation, and other non-canonical versions of field theory, e.g., tachyonic fields, in the high dissipative regime [117][118][119][120][121][122][123][124][125], while there have been also many studies involving different forms of inflaton potentials and in other interesting contexts [79,111,[126][127][128][129][130][131][132][133][134][135][136][137][138][139][140][141][142][143][144].…”

Recent developments in warm inflation

“…Moreover, there are several papers in the literature which studied WI using some quasi-de Sitter form of scale factor, e.g., intermediate and logamediate inflation, and other noncanonical versions of field theory, e.g., tachyonic fields, in the high dissipative regime [117][118][119][120][121][122][123][124][125], while there have been also many studies involving different forms of inflaton potentials and in other interesting contexts [79,111,[126][127][128][129][130][131][132][133][134][135][136][137][138][139][140][141][142][143][144].…”

Does fractal universe favour warm inflation: Observational support?

“…According to the latest observational data, the amplitude of the scalar perturbations at horizon crossing is given by P s = 2.17 × 10 −9 [39,40]. The amplitude of tensor perturbation is given by P t = 8H 2 .…”