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 $sigma_0$.
A. Cerioni, F. Finelli, A. Tronconi, G. Venturi (2009). Inflation and Reheating in Induced Gravity. PHYSICS LETTERS. SECTION B, 681, 383-386 [10.1016/j.physletb.2009.10.066].
Inflation and Reheating in Induced Gravity
CERIONI, ALESSANDRO;TRONCONI, ALESSANDRO;VENTURI, GIOVANNI
2009
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 $sigma_0$.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
