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Alpha2021
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How to determine whether a cosmological inflation model (say single-field slow-roll inflation) gracefully exit or not? Is it like showing that inflation is ending at some value of inflaton?
Thanks a lot for this kind reply.Will Learn said:Hi.
You're not getting a lot of responses, so I hope this will be of some help.
Have you got access to a library? My main source of information is "The History of the Universe", David H Lyth, publisher: Springer, 2016
It's a short book which (in my opinion) is suitable for post-graduates in a rush. It describes all the required effects of inflation on pages 71~73. However, it's in the Appendix on page 102 where some criteria for the end of inflation are established. So the whole lot is no more than 4 or 5 pages of A5 size... or 10 minutes reading (and in my case, twice as long figuring out what was going on with your own pencil and paper).
I could repeat what is said there but I can't do it any better than the original text. I read it at speed and wasn't really concerned about this aspect anyway.
Assuming I understood the text, Lyth presents criteria on V'' that mark the end of inflation.
Best Wishes.
LATE EDITING: According to the info on the back of the book, the book is appropriate for the general public EXCEPT the appendix (the thing is without the appendix you've got nothing much except some nice words anyway).
I've spent a bit more time and read the pages in the book again. Actually, there is a risk that the conditions described in the appendix are just necessary conditions. Lyth does seem to refer to the entire proposed shape of the inflaton potential (fig 14.1 in the book) as being required to guarantee an exit from inflation.Alpha2021 said:Is it sufficient?
A cosmological inflation model is a theoretical framework used to explain the rapid expansion of the universe in the early stages of its formation. It suggests that the universe underwent a period of exponential growth, causing it to expand faster than the speed of light.
The graceful exit of a cosmological inflation model is important because it explains how the universe transitioned from a period of rapid expansion to the slower expansion that we observe today. It also helps to address some of the inconsistencies and limitations of the standard Big Bang model.
A cosmological inflation model ends through a process called reheating, where the energy stored in the inflation field is converted into particles and radiation, leading to the hot and dense state of the early universe. This allows for the universe to continue expanding at a slower rate.
There is strong observational evidence supporting the concept of a graceful exit in cosmological inflation models. This includes the precise measurements of the cosmic microwave background radiation, the distribution of galaxies, and the large-scale structure of the universe.
Yes, there are different types of graceful exits in cosmological inflation models, depending on the specific inflation model being studied. Some examples include the slow-roll inflation model, the hybrid inflation model, and the chaotic inflation model, each of which has its own unique way of ending the period of rapid expansion.