Linear Growth of Cosmological Perturbations
Linear Growth of Cosmological Perturbations
This chapter shows that, after cosmological recombination, the Universe had entered the “dark ages,” during which the relic cosmic microwave background (CMB) light from the Big Bang gradually faded away. During this “pregnancy” period (which lasted hundreds of millions of years), the seeds of small density fluctuations planted by inflation in the matter distribution grew until they eventually collapsed to make the first galaxies. In addition to the density evolution, the second key “initial condition” for galaxy formation is the temperature of the hydrogen and helium gas that had likewise collapsed into the first galaxies. Here, the chapter describes the first stages of these processes and introduces the methods conventionally used to describe the fluctuations. It follows the evolution of structure in the linear regime, when the perturbations are small.
Keywords: linear growth, cosmological perturbations, dark ages, Big Bang, small density fluctuations, density evolution, galaxy formation, hydrogen, helium
Princeton Scholarship Online requires a subscription or purchase to access the full text of books within the service. Public users can however freely search the site and view the abstracts and keywords for each book and chapter.
Please, subscribe or login to access full text content.
If you think you should have access to this title, please contact your librarian.
To troubleshoot, please check our FAQs , and if you can't find the answer there, please contact us.
