The quantum-to-classical transition of inflationary cosmological perturbation is necessary to explain today’s classical observations originating from primordial vacuum fluctuation. In the literature, such a transition is the decoherence obtained by tracing out the unobserved modes from a state having couplings between long and short modes by bulk interactions. The speaker and his team note that the decoherence of inflationary curvature perturbation is dominated by a boundary term of the gravity action. Although this boundary term cannot affect normal cosmological correlators, it induces much faster decoherence than the previous calculations based on bulk interactions. They also point out that the gravitational origin of inflationary decoherence may shed light on the quantum nature of gravity. By comparing with a Schrödinger-Newton semi-classical gravity, they show that gravity theories of classical or quantum origins can be distinguished by comparing their different decoherence rates of cosmological perturbation. The result by his team also suggests that density fluctuation better preserves quantum information than curvature perturbation for the purpose of constructing cosmological Bell-like experiments.
頻道：(網上講授)Zoom ID:421-480-1692 ← cosmology
講者：SOU Chon Man(Hong Kong University of Science and Technology)
“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.