# Towards degeneracy breaking of early universe models

## TL;DR

This paper explores how to distinguish early universe models that produce similar observational signals due to conformal degeneracy by using frame-invariant variables, aiming to identify unique signatures in future observations.

## Contribution

It introduces a method using frame-invariant variables to differentiate early universe scenarios and discusses their distribution in parameter space, including explicit non-minimal coupling models.

## Key findings

- Different models occupy distinct regions in the frame-invariant parameter space.
- The approach provides a framework for future observational discrimination.
- Concrete models with non-minimal coupling are analyzed.

## Abstract

There are many possibilities of scenarios in the early universe, which can give rise to the same observational signals due to the degeneracy among each other, caused by equivalence under the conformal transformations. In order to break the degeneracy, in this paper we take into account the so-called "frame-invariant variables" proposed by A. Ijjas and P. J. Steinhardt in \cite{Ijjas:2015zma}. We discuss how the different scenarios will distribute in different parametric space constructed from those variables, waiting for the judgement of real observations in the future. Several concrete models with explicit non-minimal coupling functions are also discussed.