Chaotic Inflation Models & Equations

AI Thread Summary
In chaotic inflation models, the Friedmann equation is applied with H expressed as H = sqrt(8 pi G / 3) * V(Phi), where V(Phi) is often defined as ½ m^2 Phi^2. There is interest in converting V(Phi) into mass/volume units, although this is complicated by the use of natural units in these theories. The challenge lies in the difficulty of assigning accurate mass/volume values, which limits the frequency of such calculations. While rough estimates for mass density in the universe can be derived, they are highly dependent on the specific model used. Overall, the conversion of V(Phi) into mass/volume remains a complex issue in the context of chaotic inflation.
edgepflow
Messages
688
Reaction score
1
When using the Friedmann equation (flat space, no cosmological constant): H = sqrt (8 pi G / 3 ) * rho, if we use rho in mass/volume, H is in (time)^-1 like it should. Now for some inflation models, we use: H = sqrt (8 pi G / 3 ) * V(Phi). It seems that V(Phi) should also be able to be converted to mass/volume.

In chaotic inflation models, the function V(Phi) = ½ m^2 Phi^2 is often used. I know “natural units” are employed in these theories, but I was wondering if there is a way to convert V(Phi) = ½ m^2 Phi^2 into units of mass/volume?
 
Space news on Phys.org
Inability to ascribe accurate values for mass/volume is the usual reason this calculation is not attempted very often. We can derive a rough estimate for mass density in the universe, but is highly model dependent. Working backwards from such estimates has been the usual approach, AFAIK.
 
https://en.wikipedia.org/wiki/Recombination_(cosmology) Was a matter density right after the decoupling low enough to consider the vacuum as the actual vacuum, and not the medium through which the light propagates with the speed lower than ##({\epsilon_0\mu_0})^{-1/2}##? I'm asking this in context of the calculation of the observable universe radius, where the time integral of the inverse of the scale factor is multiplied by the constant speed of light ##c##.
The formal paper is here. The Rutgers University news has published a story about an image being closely examined at their New Brunswick campus. Here is an excerpt: Computer modeling of the gravitational lens by Keeton and Eid showed that the four visible foreground galaxies causing the gravitational bending couldn’t explain the details of the five-image pattern. Only with the addition of a large, invisible mass, in this case, a dark matter halo, could the model match the observations...
Hi, I’m pretty new to cosmology and I’m trying to get my head around the Big Bang and the potential infinite extent of the universe as a whole. There’s lots of misleading info out there but this forum and a few others have helped me and I just wanted to check I have the right idea. The Big Bang was the creation of space and time. At this instant t=0 space was infinite in size but the scale factor was zero. I’m picturing it (hopefully correctly) like an excel spreadsheet with infinite...

Similar threads

Replies
3
Views
3K
Replies
1
Views
2K
Replies
29
Views
3K
Replies
4
Views
2K
Replies
3
Views
2K
Replies
27
Views
5K
Replies
12
Views
2K
Back
Top