Speaker
Thomas Hertog
(KU Leuven)
Description
I discuss two striking new insights into the fundamentals of the Hartle-Hawking no-boundary wave function. First, I show that the Kontsevich–Segal criterion, applied to the complex saddles that specify the semiclassical no-boundary wave function, acts as a selection mechanism on inflationary scalar field potentials. This saddle criterion effectively bounds the tensor-to-scalar ratio of cosmic microwave background fluctuations to be less than 0.08, in line with current observations. Second, moving beyond the semiclassical approximation, I explain how quantum corrections to the entropy of four-dimensional de Sitter space can be computed using the AdS/CFT correspondence.
