Scale-Independent Inflation and Hierarchy Generation

TL;DR

This paper explores models with two scalar fields coupled to gravity that dynamically generate the Planck scale, achieve inflation, and naturally produce hierarchies without input mass parameters, relying on classical scale symmetry.

Contribution

It introduces a class of scale-invariant two-scalar models that realize inflation and hierarchy generation through spontaneous symmetry breaking.

Findings

Planck mass generated by scalar VEVs

Successful slow-roll inflation achieved

Small cosmological constant in the vacuum

Abstract

We discuss models involving two scalar fields coupled to classical gravity that satisfy the general criteria: (i) the theory has no mass input parameters, (ii) classical scale symmetry is broken only through $-\frac{1}{12}\varsigma \phi^2 R$ couplings where $\varsigma$ departs from the special conformal value of $1$; (iii) the Planck mass is dynamically generated by the vacuum expectations values (VEVs) of the scalars (iv) there is a stage of viable inflation associated with slow roll in the two--scalar potential; (v) the final vacuum has a small to vanishing cosmological constant and an hierarchically small ratio of the VEVs and the ratio of the scalar masses to the Planck scale. This assumes the paradigm of classical scale symmetry as a custodial symmetry of large hierarchies.