Cosmological Perturbations in the Early Universe

<p>One essence in capturing the history of primordial fluctuations that arise during inflation and eventually lead to formation of large scale structures in the universe, relies on quantizing general relativity coupled to a scalar field. This is a system that respects diffeomorphism invariance, the freedom of choosing the coordinate system to work with without changing the physics. Hence the way to handle its quantization requires an understanding of how to quantize diffeomorphisms. Deciding on suitable coordinate choices and making sure that this gauge fixing, which is unavoidable in any calculation, does not effect the end result, is tricky. In this thesis we make full use of the effects of diffeomorphism invariance of the theory on the primordial fluctuations to pursue two different approaches that focus on treating perturbations after gauge fixing. On one hand we work towards developing our understanding of how to handle quantization in terms of Dirac quantization and Becchi, Rouet, Stora, Tyutin (BRST) quantization. On another, we focus on how to generalize the allowed interactions and understand the scales they bring in the era of preheating that follows inflation, with effective field theory (EFT) methods on cosmological backgrounds.</p>

Name thesis:degree_name

Doctor of Philosophy (PhD)

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physics

Year

2018

Author dc:creator

• Sengor, Gizem

Contributors dc:contributor

• Gary S. Watson
• William Wylie

• high energy physics
• inflation
• reheating
• theoretical cosmology
• Physical Sciences and Mathematics

Repository record dc:identifier

https://surface.syr.edu/etd/902

OAI identifier oai:identifier

oai:surface.syr.edu:etd-1903