Simple no-scale model of modulus fixing and inflation

John Ellis,Antonio Enea Romano,Óscar Zapata,Malcolm Fairbairn

doi:10.1103/physrevd.98.103514

Abstract

We construct a no-scale model of inflation with a single modulus whose real and imaginary parts are fixed by simple power-law corrections to the no-scale K{\" a}hler potential. Assuming an uplift of the minimum of the effective potential, the model yields a suitable number of e-folds of expansion and values of the tilt in the scalar cosmological density perturbations and of the ratio of tensor and scalar perturbations that are compatible with measurements of the cosmic microwave background radiation.

Highlights

Cosmological inflation [1,2,3,4] provides one of the most promising arenas for probing physics close to the Planck scale, potentially even providing a window onto string theory
Assuming an uplift of the minimum of the effective potential, the model yields a suitable number of e-folds of expansion and values of the tilt in the scalar cosmological density perturbations and of the ratio of tensor and scalar perturbations that are compatible with measurements of the cosmic microwave background radiation
We have presented in this paper a simple scenario for fixing both components of the modulus T in the minimal no-scale supergravity model with Kähler potential K 1⁄4 −3 lnðT þ T†Þ, which is partly based upon theoretical calculations of corrections to this structure [23,24]

Summary

INTRODUCTION

Cosmological inflation [1,2,3,4] provides one of the most promising arenas for probing physics close to the Planck scale, potentially even providing a window onto string theory. The simplest no-scale supergravity model has a single complex field T that parametrizes a noncompact SU(1,1)/ U(1) coset manifold with a Kähler potential K 1⁄4 −3 lnðT þ TÃÞ [9,10], and would correspond to the volume modulus in a string compactification [19] It is a muchdebated, very general and open, question how the values of the real and imaginary components of this and other compactification moduli could be fixed dynamically in the low-energy physical vacuum [20,21].1. This model provides a successful scenario for inflation in the context of a minimal string-inspired noscale supergravity model

THE EFFECTIVE POTENTIAL AND MODULUS FIXING

A REALIZATION OF INFLATION

CONCLUSIONS