Webinar “Instability and gravitational waves in axion inflation with strong backreaction from gauge modes”

The speaker will talk about a model in which an inflaton, through an axionic coupling to a U(1) gauge field, causes an amplification of the gauge field modes that strongly backreact on its dynamics. In particular, he will discuss, using analytical formulae, an instability of the system that emerges when one considers the evolution of the gauge field modes coupled to the inflaton zero mode, treating perturbatively the deviation of the inflaton velocity from its mean-field value. This analysis confirms previous numerical results. He will also discuss two different numerical studies of the system in the same regime, showing how this behavior can generate peculiar observable features in the spectrum of gravitational waves produced by the modes of the gauge field.

時間:2024.01.23(二) 22:00~23:00
頻道:Zoom ID:421-480-1692 ← cosmology
講者:Lorenzo Sorbo (University of Massachusetts, US)



“Copernicus Webinar and Colloquium Series”: To promote scientific discussions during this pandemic, they are organizing an online seminar series, i.e. Copernicus Webinar Series, seeking the most outstanding speakers to introduce innovative ideas and important progress in the field of gravity and cosmology. This series is named after the famous Polish Astronomer, Nicolaus Copernicus, whose discovery eventually marked the dawn of modern science.




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