All Questions
16
questions
2
votes
0
answers
24
views
Why is there an infinite supply of energy in slow-roll inflation?
The physical model of inflation includes a metastable false vacuum, or a slow-roll field on a flat potential. In either case, I just realized how this is completely insane. With the exponential growth ...
- 619
1
vote
1
answer
89
views
Cosmological Constant Problem calculations involving energy densities
I am following Timo Weigand lecutre notes on QFT, on page 28, he breifly touches on the Cosmological Constant Problem.
But I am a little confused.
He begins with a Lagrangian and include a nonzero $V_{...
- 489
1
vote
2
answers
152
views
Whether vacuum energy gravitate?
What is the relationship between vacuum energy and gravity, particularly in terms of gravitational effects and its contribution to the overall cosmological constant? Does vacuum energy possess ...
2
votes
2
answers
125
views
How should we deal with interactions not from a “fundamental force”? [closed]
Question
Should the cosmological constant and/or vacuum energy be listed as one of the fundamental interactions?
If not, how can we have actual energy and forces that are not assignable to one of the ...
- 3,365
7
votes
1
answer
511
views
Does zero point energy really contribute to the cosmological constant?
The zero point energy is usually supposed to contribute to the cosmological constant. And the mismatch between the small cosmological constant compared with the huge zero point energy is deemed as one ...
- 4,452
3
votes
1
answer
519
views
Cut-off energy necessary to avoid vacuum catastrophe
My understanding is that to obtain a finite vacuum energy density prediction from QFT, one must choose a cut-off point for the maximum allowed energy of a photon. Two seemingly natural choices are the ...
- 153
4
votes
2
answers
446
views
Can Higgs potential provide a cosmological constant?
Usually, in particle physics, people do not care about a constant term in scalar field potential. Rather, attentions are paid to the local profile at the minimum. But in the context of cosmology, the ...
- 3,691
5
votes
2
answers
301
views
Is the cosmological constant problem real? [duplicate]
The cosmological constant problem assumes that the cosmological constant (determined experimentally) can be identified with the vacuum energy density. Theroretical arguments from quantum gravity ...
- 191
0
votes
0
answers
48
views
Quintessential models for dark energy
Following Sean Carroll here
There are good reasons to consider dynamical dark energy as an alternative to an honest cosmological constant. First, a dynamical energy density can be evolving slowly ...
0
votes
0
answers
96
views
How come the universe is considered flat if zero point energy is infinite?
If quantum field theory calculates that the vacuum energy is infinite and Einstein's theory of gravity implies this energy should produce a curvature of space-time then why shouldn't the universe be ...
5
votes
0
answers
158
views
Meaning of the simplest potential of quintessence models. Fields in denominator?
I am reading Sec. 1.12 of the Cosmology book by Weinberg.
In this section he explains the very simple model of quintessence which attempts to provide a dynamical explanation of the smallness of the ...
- 2,197
3
votes
1
answer
95
views
Would the formulation of a theory of quantum gravity in the presence of a nonzero cosmological constant depend on the origin of the latter?
The cosmological constant is the coefficient of a term in the Einstein tensor for which there are no a priori reasons to assume it to be zero, so that it could be regarded as a fundamental constant of ...
- 9,304
0
votes
0
answers
280
views
The theoretical calculation underlying the cosmological constant problem
The electroweak vacuum energy density is $10^{120}$ times larger than the currently observed value of the dark energy. I have two questions in regard to this statement.
$\bullet$ Firstly, what are ...
- 26.8k
2
votes
1
answer
576
views
Understanding the energy density of the the false vacuum
This note by Alan Guth says that
The false vacuum, however, cannot rapidly lower its energy density, so the energy density remains constant and the total energy increases. Since energy is conserved,...
- 26.8k
2
votes
2
answers
1k
views
What is the source of vacuum energy during the inflationary era?
It is assumed that during the inflationary epoch the universe is dominated by the vacuum energy. What is the source of this vacuum energy and how it that related to the energy of the inflaton field?
- 26.8k