Multifield inflation and differential geometry

Cosmic inflation posits that the universe underwent a period of exponential expansion, driven by one or several quantum fields, shortly after the Big Bang. Renormalization requires the fields be non-minimally coupled to gravity. We examine such multifield models and find a rich geometric structure. After a conformal transformation of spacetime, the target field-space acquires non-trivial curvature. We explore two main consequences. First, we construct a field-space covariant framework to study quantum perturbations, extending prior work beyond the slow-roll approximation by working on the full phase space of the theory. Secondly, we show that a wide class of inflationary models can be understood as a geodesic motion on a suitably related manifold. Our geometric approach provides great insight into the (classical) field dynamics, and we have used them to compute non-gaussianities in the cosmic microwave background radiation spectrum.

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Physics.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2013

Author dc:creator

• Mazenc, Edward A

Advisor dc:contributor.advisor

• David I. Kaiser.

• Physics.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/83809

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/83809