# Quantum-gravity effects for excited states of inflationary perturbations

**Authors:** David Brizuela, Claus Kiefer, Manuel Kraemer, Salvador Robles-Pérez  
**arXiv:** [1903.01234](https://arxiv.org/abs/1903.01234)  
**Date:** 2019-03-04  
**Summary page:** https://www.summarizepaper.com/en/paper/1903.01234v1/

## Key points

- Authors: David Brizuela, Claus Kiefer, Manuel Kraemer, Salvador Robles-Pérez
- Study focus: Quantum-gravitational corrections in perturbed FLRW universe during inflation
- Key finding: Quantum-gravitationally corrected power spectra modified by pre-factors with excitation numbers
- Implications: More nuanced understanding of quantum effects in inflationary perturbations
- Contribution: Advancing comprehension of quantum gravity's role in early universe dynamics
- Insight: Excited states offer fresh perspective on impact of deviations from traditional vacuum states on cosmological outcomes

## Summary

In their paper titled "Quantum-gravity effects for excited states of inflationary perturbations," authors David Brizuela, Claus Kiefer, Manuel Kraemer, and Salvador Robles-Pérez delve into the realm of quantum-gravitational corrections within a perturbed FLRW universe during inflation. Building upon previous research, the team explores the implications of considering an initial state for scalar and tensor perturbations that goes beyond the traditional adiabatic vacuum state. By allowing for the scenario where perturbation modes begin their evolution in an excited state, the researchers uncover intriguing insights. Their study reveals that these quantum-gravitationally corrected power spectra undergo modifications influenced by pre-factors that incorporate the excitation numbers. This finding suggests a more nuanced understanding of how quantum effects manifest in the context of inflationary perturbations. Through their exploration of excited states in this cosmological framework, Brizuela et al. contribute to advancing our comprehension of quantum gravity's role in shaping the early universe's dynamics. Overall, this research sheds light on the intricate interplay between quantum phenomena and gravitational interactions during cosmic inflation, offering a fresh perspective on how deviations from traditional vacuum states can impact observable outcomes in cosmology.