PIRSA:11070017

Scale Invariance from Spontaneous Breaking of Conformal Symmetry

APA

Khoury, J. (2011). Scale Invariance from Spontaneous Breaking of Conformal Symmetry. Perimeter Institute for Theoretical Physics. https://pirsa.org/11070017

MLA

Khoury, Justin. Scale Invariance from Spontaneous Breaking of Conformal Symmetry. Perimeter Institute for Theoretical Physics, Jul. 14, 2011, https://pirsa.org/11070017

BibTex

          @misc{ scivideos_PIRSA:11070017,
            doi = {10.48660/11070017},
            url = {https://pirsa.org/11070017},
            author = {Khoury, Justin},
            keywords = {Cosmology},
            language = {en},
            title = {Scale Invariance from Spontaneous Breaking of Conformal Symmetry},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2011},
            month = {jul},
            note = {PIRSA:11070017 see, \url{https://scivideos.org/index.php/pirsa/11070017}}
          }
          

Justin Khoury University of Pennsylvania

Talk numberPIRSA:11070017
Talk Type Conference
Subject

Abstract

I will discuss a novel framework of the very early universe which addresses the traditional horizon and flatness problems of big bang cosmology and predicts a scale invariant spectrum of perturbations. Unlike inflation, this scenario requires no exponential superluminal expansion of space-time. Instead, the early universe is described by a conformal field theory minimally coupled to gravity. The conformal fields develop a time-dependent expectation value which breaks the flat space so(4,2) conformal symmetry down to so(4,1), the symmetries of de Sitter, giving perturbations a scale invariant spectrum. The solution is an attractor, at least in the case of a single time-dependent field. Meanwhile, the metric background remains approximately flat but slowly contracts, which makes the universe increasingly flat, homogeneous and isotropic. The essential features of the scenario depend only on the symmetry breaking pattern and not on the details of the underlying lagrangian.