CPT Colloquia

Charlotte Sleight (Durham) - "Inflation as a hologram"




In the search for a complete description of quantum mechanical and gravitational phenomena we are inevitably led to consider observables on boundaries at infinity. This is the holographic principle: A purely boundary--or holographic--description of physics in the interior.  The AdS/CFT correspondence provides an important working example of the holographic principle, where the boundary description of quantum gravity in anti-de Sitter (AdS) space is an ordinary quantum mechanical system that is, in particular, given by a Conformal Field Theory (CFT). This is particularly striking as CFTs are important and well-studied landmarks in the landscape of QFTs, where any given CFT can describe a variety of physical systems of criticality from boiling water to ferromagnets - all of which are much less daunting than the question mark that is quantum gravity. It is natural to ask if AdS/CFT correspondence could be used to improve our understanding of the universe we actually live in. I will explain how spatial correlations at the end of the inflationary epoch can be (formally) recast as correlation functions on the boundary of anti-de Sitter space, opening up the possibility to import techniques, results and understanding from AdS/CFT to inflationary cosmology.