Primordial scalar perturbations are always considered as a source in the study of large-scale structures. Being the dominant ones at first order in perturbation theory, they have also encouraged the study of generation of second order gravitational waves from them. The speaker and her team seek to investigate the opposite effect, i.e. if gravitational waves can have an observable contribution on the matter power spectrum in the second order. For this, they consider gravitational waves with broken scale-invariance, which happens in some models of inflation. Their results are positive about having a significant effect, and they notice a crucial characteristic of this new effect, unlike the standard matter perturbation, it does not exist outside the horizon scales, although on smaller scales it can be said that it mimics the linear one.
頻道：(網上講授)Zoom ID:421-480-1692 ← cosmology
講者：Pritha Bari(Padua University)
“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.