Compact object mergers offer a new and independent means of measuring the Hubble constant by combining the source’s distance derived from the gravitational wave form with its redshift obtained from electromagnetic follow-up. It is expected that with a few tens of events, this multi-messenger method could reach a precision fit to resolve the pending tension between early- and late-Universe...
We have recently proposed a new model-independent mechanism for producing primordial black holes from a period of multi-field inflation. The desired enhancement of primordial fluctuations at short scales naturally occurs when the inflationary trajectory exhibits a strong turn, that is a limited period during which the trajectory strongly deviates from a geodesic in field space. The mechanism,...
Les cordes cosmiques sont des défauts topologiques unidimensionnels formés à la suite d'une brisure spontanée de symétrie. Si des cordes cosmiques ont été formées dans l'Univers primordial, elles peuvent être à l'origine d'un fond stochastique d'ondes gravitationnelles détectable dans une large bande de fréquence. La détection d'un tel signal permettrait de contraindre les extensions du modèle...
