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arXiv · 1903.01497

Geometrical Destabilisation of Ultra-Light Axions in String Inflation

Michele Cicoli·Veronica Guidetti·Francisco G. Pedro
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Abstract

We perform a detailed analytical and numerical analysis of the multi-field evolution of Fibre Inflation and show that, regardless of the microscopic realisation of the model, the mass-squared of one of the two ultra-light axions becomes always negative during inflation. This implies that the corresponding isocurvature perturbations experience a potential geometrical destabilisation which seems to bring the system away from the perturbative regime. Therefore we conclude that a full understanding of the inflationary evolution of Fibre Inflation can be achieved only via a non-perturbative analysis where the backreaction of tachyonic isocurvature perturbations is properly taken into account.

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Michele Cicoli, Veronica Guidetti, Francisco G. Pedro. 2019-03-04. Geometrical Destabilisation of Ultra-Light Axions in String Inflation. https://doi.org/10.1088/1475-7516%2F2019%2F05%2F046

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