Properties of Scalar Perturbations Generated by Conformal Scalar Field

Scalar Perturbations and Conformal Transformation

The non-minimal coupling of gravity to a scalar field can be transformed into a minimal coupling through a conformal transformation. We show how to connect the results of a perturbation calculation, performed around a Friedmann-Robertson-Walker background solution, before and after the conformal transformation. We work in the synchronous gauge, but we discuss the implications of employing other...

Exact Conformal Scalar Field Cosmologies ∗

New exact solutions of Einstein’s gravity coupled to a self-interacting conformal scalar field are derived in this work. Our approach extends a solution-generating technique originally introduced by Bekenstein for massless conformal scalar fields. Solutions are obtained for a FriedmannRobertson-Walker geometry both for the cases of zero and non-zero curvatures, and a variety of interesting feat...

Inflation from a massive scalar field and scalar perturbations of the metric

In the framework of chaotic inflation we study the case of a massive scalar field using a semiclassical approach. We derive the energy density fluctuations in the infrared sector generated by matter field and gauge-invariant metric fluctuations by means of a different method. We find that the super Hubble density fluctuations increase during inflation for a massive scalar field, in agreement wi...

Infrared Properties of Scalar Field Theories

Conformal Transformations of S-Matrix in Scalar Field Theory

Institut für Theoretische Physik, Universität Leipzig, Augustusplatz 10/11, D 04109 Leipzig, Germany Abstract In this paper, three methods for describing the conformal transformations of the S-matrix in quantum field theory are proposed. They are illustrated by applying the algebraic renormalization procedure to the quantum scalar field theory, defined by the LSZ reduction mechanism in the BPHZ...