Séminaire / Seminar GReCO |
| « A universal scaling law for sourced inflationary gravitational waves and applications » |
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Martin Teuscher |
| We consider the gravitational wave (GW) background induced by arbitrary source fields that are amplified during inflation. We first conduct a very general analysis where the associated tensor spectral index $n_T$ is shown to be given, under minimal assumptions, by a simple and ready-to-use formula. Remarkably, we demonstrate that during slow-roll inflation $n_T$ becomes completely independent of the original spectrum of the source, exhibiting a universal near scale invariance. We then refine our study to the case of GWs induced by abelian gauge fields, covering the case of axion inflation. We analytically derive the amplitude of GWs and argue that they can overtake the standard inflationary GW background. We use this to constrain the values of gauge field couplings allowed by observations. This presentation is based on arXiv:2510.00869 and arXiv:2512.14670. |
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lundi 9 février 2026 - 11:00 Salle des séminaires Évry Schatzman Institut d'Astrophysique de Paris |
| Pages web du séminaire / Seminar's webpage |