Inflation is studied in the context of induced gravity (IG) $gamma sigma^2 R$, where $R$ is the Ricci scalar, $sigma$ a scalar field and $gamma$ a dimensionless constant. We study in detail cosmological perturbations in IG and examine both a Landau-Ginzburg (LG) and a Coleman-Weinberg (CW) potential toy models for small field and large field (chaotic) inflation and find that small field inflationary models in IG are constrained to $gamma lesssim 3 times 10^{-3}$ by WMAP 5 yrs data. Finally we describe the regime of coherent oscillations in induced gravity by an analytic approximation, showing how the homogeneous inflaton can decay in its short-scale fluctuations when it oscillates around a non-zero value $sigma_0$.
Titolo: | Inflation and Reheating in Induced Gravity |
Autore/i: | CERIONI, ALESSANDRO; F. Finelli; TRONCONI, ALESSANDRO; VENTURI, GIOVANNI |
Autore/i Unibo: | |
Anno: | 2009 |
Rivista: | |
Digital Object Identifier (DOI): | http://dx.doi.org/10.1016/j.physletb.2009.10.066 |
Abstract: | Inflation is studied in the context of induced gravity (IG) $gamma sigma^2 R$, where $R$ is the Ricci scalar, $sigma$ a scalar field and $gamma$ a dimensionless constant. We study in detail cosmological perturbations in IG and examine both a Landau-Ginzburg (LG) and a Coleman-Weinberg (CW) potential toy models for small field and large field (chaotic) inflation and find that small field inflationary models in IG are constrained to $gamma lesssim 3 times 10^{-3}$ by WMAP 5 yrs data. Finally we describe the regime of coherent oscillations in induced gravity by an analytic approximation, showing how the homogeneous inflaton can decay in its short-scale fluctuations when it oscillates around a non-zero value $sigma_0$. |
Data prodotto definitivo in UGOV: | 2009-12-02 08:36:18 |
Appare nelle tipologie: | 1.01 Articolo in rivista |