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Strong Backreaction Regime in Axion Inflation
Daniel G Figueroa1, Joanes Lizarraga2,3, Ander Urio2,3
1Instituto de Física Corpuscular (IFIC), Consejo Superior de Investigaciones Científicas (CSIC) and Universitat de València, 46980, Valencia, Spain.
Physical Review Letters
|October 28, 2023
Summary
This study reveals how axion inflation
Area of Science:
- Cosmology
- Particle Physics
Background:
- Axion inflation is a leading model for the early universe.
- Previous studies often assumed spatial homogeneity, neglecting crucial dynamical effects.
Purpose of the Study:
- To investigate the nonlinear dynamics of axion inflation, including inhomogeneity and strong backreaction.
- To capture the full dynamical range of axion inflation until its end.
Main Methods:
- Nonlinear dynamics simulations.
- Analysis of inhomogeneous effects during axion inflation.
Main Results:
- Inhomogeneity significantly increases e-foldings with coupling.
- Oscillations in inflaton velocity are attenuated.
- Tachyonic helicity spectra are smoothed and blue-shifted.
- Nontachyonic helicity is excited, creating scale-dependent chiral asymmetry.
Conclusions:
- Inhomogeneous axion inflation yields distinct results from homogeneous models.
- These findings impact gravitational wave and primordial black hole predictions.
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