Tagged Questions
1
vote
0answers
41 views
The definition of $f_{NL}$ and transfer function
To me there seems to be quite a few different definitions of $f_{NL}$ in cosmology and I would like to know if or how they are equivalent. Let me cite at least 3 such,
One can see the equation 6.71 ...
3
votes
3answers
220 views
Question on inflation
I have two particular questions regarding the inflationary scenario. They are:
1.) What is the physical origin of the inflaton field?
2.) Why has the potential of the inflation field its particular ...
3
votes
1answer
122 views
Question on inflation as a phase transition
I have just finished watching the following video http://www.youtube.com/watch?v=beQ9fZ0jVdE where Laughlin, Gross and some students discuss e.g. about inflation. The following question is risen:
Is ...
2
votes
0answers
67 views
Is eternal inflation Lorentz invariant?
Start without general relativity. Consider a metastable vacuum over good ol'-fashioned Minkowski space. It decays. A bubble forms and the domain wall expands. The domain wall is timelike, and ...
2
votes
2answers
158 views
What are the limitations of the FLRW metric?
I was wondering, given how in any other area of life making an explosion spherically symmetric is more or less impossible is there any reason to expect that the universe is? I appreciate that the FLRW ...
1
vote
2answers
287 views
How long did inflation take to happen?
If inflation happened, it ended about 13.7 billion years ago. But how long was inflation going on before that? Was it just a short burst of time so that it's really okay to say that the age of the ...
2
votes
1answer
145 views
Does anisotropic expansion of the universe imply quintaessence?
a Recent paper establishes under solid grounds anisotropy in the expansion acceleration rate in the universe. My question is very simple:
can this anomaly be explained entirely in terms of a ...
10
votes
2answers
425 views
Can “big rip” rip apart an atomic nucleus?
Some scenarios describing the fate of the matter vs dark energy tug of war on the universe involve the acceleration of the universe increasing to the point that it ends up ripping apart even atoms. ...
5
votes
5answers
2k views
What is the evidence for Inflation of the early universe?
The theory of Inflation explains the apparent consistency of the universe by proposing that the early universe grew exponentially for a 1E-36 seconds. Isn't a simpler explanation that the universe is ...
