# The Effective Field Theory of nonsingular cosmology: II

## TL;DR

This paper clarifies and resolves instabilities in nonsingular cosmological models using Effective Field Theory, introduces a Genesis-inflation model, and explores its implications for primordial perturbations and CMB anomalies.

## Contribution

It identifies and cures instabilities in nonsingular cubic Galileon models within EFT, proposing a new Genesis-inflation model with potential observational signatures.

## Key findings

- Resolved instabilities in nonsingular models
- Constructed a Genesis-inflation scenario
- Predicted a large-scale cutoff in primordial spectrum

## Abstract

Based on the Effective Field Theory (EFT) of cosmological perturbations, we explicitly clarify the pathology in nonsingular cubic Galileon models and show how to cure it in EFT with new insights into this issue. With the least set of EFT operators that are capable to avoid instabilities in nonsingular cosmologies, we construct a nonsingular model dubbed the Genesis-inflation model, in which a slowly expanding phase (namely, Genesis) with increasing energy density is followed by slow-roll inflation. The spectrum of the primordial perturbation may be simulated numerically, which shows itself a large-scale cutoff, as the large-scale anomalies in CMB might be a hint for.