The cosmological-inflation tag has no wiki summary.
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Cosmic Inflation: Lower Expansion Rate with than without?
When I read the Cosmic Inflation diagram at
https://en.wikipedia.org/wiki/File:Horizonte_inflacionario.svg
which I rotated to make it readable:
where the Hubbleradius, and therefore also the ...
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3answers
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Acceleration in the rate of expanansion of the universe due to weakening gravity?
Could the acceleration in the rate of expansion of the universe be due to the weakening of gravitational forces, as the distance between objects continues to increase?
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On the necessity of inflation [closed]
The relationship between the past and the current
Ads/CFT = AC/DC x K, where K = (D x D x s)/(C x F x T)
can be rewritten as
Ads/CFT = ADs/CFT
Question: Can the concept of cosmological inflation ...
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How can dynamics be reversible if inflation-style baby universe spawning is allowed?
I just finished readying Sean Carroll's book, "From Eternity to Here", and have a question about reversibility and inflation:
Assume inflation allows random quantum fluctuations to produce high ...
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What is the speed of acceleration of the inflation of the universe?
Is the inflation speed of the universe accelerating or is it a constant speed of expansion proportional to distance between objects.
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Inflation and scalar spectral index
I've been reading that the results from the Planck satellite constrain a number called the "scalar spectral index" to be 0.96 rather than 1 at the 5-sigma level.
This is supposed to be big news, but ...
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1answer
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Tensor perturbation inflation
During inflation the metric is de-Sitter so $dt^2-d\underline{X}^2 $.
I know that the eqn.motion governing GW's from inflation (tensor perturbations) is
$$2H\dot{h}+\ddot{h}-\nabla^{2}_{i}h~=~0,$$ ...
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1answer
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Observable (in principle) signal of a bubble collision in eternal inflation
Assuming a scenario of eternal inflation with a lot of "bubble universes" expanding, Lenny Susskind explains here that a potential signal of a collision of our universe with another bubble could be a ...
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Hybrid Inflation and Supergravity
Is it necessary to add a constant term in the superpotential of hybrid inflation within supergravity in order to cancel SUSY vacuum energy at the end of inflation?
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Quantum Entanglement Versus Inflation in the Early Universe?
Quantum entanglement is one of the most fascinating and mysterious phenomena in nature. It needs no interactions, or any sort of exchange for it to take place. It is possible, not against any rules of ...
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Is Inflation modelled by a field?
If Inflation is modelled by a field - is this a classical field or a quantum field? If classical are there good reasons not to quantise it? What are the implications of such a quantisation?
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1answer
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Is the redshift of ancient stars less than constant linear expansion predicts?
When accelerated expansion of universe was discovered, the astronomers used redshift of ancient stars. Say if star is 10 billion years in the past, then it should be moving faster than star from 5 ...
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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 ...
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$f_{NL}$ non-Gaussianity in cosmology
In the context of cosmology, what is meant by "..arbitrary quadratic non-Gaussianity i.e non-Gaussianity that is described to leading order by a 3-point function.."? (.."quadratic non-Gaussianity" ...
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3answers
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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 ...
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1answer
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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 ...
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P-adic Numbers and Eternal Inflation
In October(??) 2011, Leonard Susskind gave a talk and with few other people wrote papers about p-adic numbers and measure problems in cosmology, see e.g. arXiv:1110.0496. Has there been any recent ...
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Theoretical early-universe cosmology [closed]
I wanted to know what are the cutting edge/recent papers to read w.r.t theoretical early universe cosmology.
I would like to know of recent review papers
I would like to know of areas which use ...
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1answer
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How does an inflationary universe solve the Flatness Problem, Horizon Problem and Monopole Problem? [duplicate]
Possible Duplicate:
What is the evidence for Inflation of the early universe?
I am reading some public science books on inflationary universe, e.g. The Inflationary Universe by A. Guth.
...
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Can decompactification explain the inflation of the early universe?
I've just reread chapter 11 of this book where it is explained among other things, that our four dimensional universe could be unstable concerning a decompactification transition, since potential ...
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3answers
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Why the red-shift of distant galaxies is considered to be the effect of expanding spacetime?
Why it's not explained just by Doppler redshift caused by faster movement of those galaxies billions of years ago when that light was emitted?
Would the speeds of the galaxies necessary for Doppler ...
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1answer
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false vacuum original paper
I'm trying to track down the origin of the False Vacuum paradigm. Is it Coleman and de Luccia's "Gravitational Effects on and of Vacuum Decay"
...
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Is it really true that slow-roll inflation is incompatible with string theory?
In this blog post, Motl claimed that slow-roll inflation is incompatible with string theory. Is that really true, and why do people think so?
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3answers
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Could dark energy be powered by force particles that obey quantum mechanics?
From what (little) I know about physics, I understand that the universe is expanding due to dark energy, and I understand that no one quite understands it yet. I also understand that the cosmic ...
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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 ...
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3answers
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Will the Big Rip tear black holes apart?
There seems to be an obvious contradiction between the predictions of the physics of black holes and the Big Rip, a predicted event about 16.7 Gyr in the future where local groups, galaxies, solar ...
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Size of universe after inflation?
Wikipedia states the period of inflation was from $10^{-36}$sec to around $10^{-33}$sec or $10^{-32}$sec after Big Bang, but it doesn't say what the size of the universe was when inflation ended. ...
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Can cosmic inflation be explained by matter antimatter reactions?
The big bang theory proposes that equal amounts of matter and antimatter were created in the beginning. Shortly afterwards most of it annihilated. Could that have produced enough energy to drive ...
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2answers
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Why is the thomson cross section constant over cosmological time?
In all astrophysical calculations I'm aware of, the thomson cross-section (for electron scattering) is taken as a constant in time, why is this the case? I have only weak experience in cosmology and ...
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2answers
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How does universal inflation fit with the Planck length?
If the universe is undergoing inflation, and there is a minimum scale that things can exist at (the Planck length), does that mean that new Planck-sized domains have to be continuously popping into ...
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1answer
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How fast was the universe expanding during the inflationary period?
Compared to how fast it is expanding in the post-inflationary period (now)
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The multiverse of eternal inflation
I don't have a clear picture of what is "by definition" the multiverse appearing in the models of eternal inflation. A long time ago I heard that it is a quantum state, but in the cosmology books I ...
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1answer
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What would be the effects of an inflating universe?
If our universe is inflating, which means it is getting bigger and bigger in size, and every thing it consists of is also enlarging, in a special way such that the mass of the universe remains ...
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1answer
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If the unobservable universe is not “open” and will collapse, would we be able to tell?
Assuming hypothetically that it happens now while we are alive and analyzing our observable universe. If the unobservable universe collapses in a "Big Crunch", will we see its effects in our ...
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String theory landscape and false vacua
What is the multiverse of string theory? I always thought it would be from brane cosmology where there's chances for multiple collisions of the branes that can make a universe. So this "multiverse" ...
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1answer
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Why is Hawking's No Boundary condition described in terms of an instanton if there's no tunneling?
Regarding his take about combining No Boundary proposal with inflation theory (Hawking and Turok), he talks about the "pea instanton".
To my very limited understanding I thought instantons were only ...
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1answer
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Is the FRW metric describing the shape of the universe or the shape of the expansion applied to the universe?
Is it (the output, i.e, spherical, flat, hyperbolic) describing the physical shape of the universe and its curvature at any given instance of time or is it describing the shape of the expansion ...
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Could the unobservable universe have curvature (be spherical)?
What prevents the unobservable universe from being a continuously enlarging sphere due to the inflating bubble universes? Our observable universe being close to flat could support such a scenario?
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How did the inflaton field “add” energy to the universe?
How did inflation add energy to the universe? What mechanism did this occur by? In other words, where did that energy come from? Was it due to the quantum fluctuation (or that scalar field rolling ...
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Why does inflation (the inflaton field) push Omega down closer to zero (flatten the universe)?
I know that in our particular case the inflaton field expanded the volume of the universe while simultaneously maintaining a mass-energy density close to the critical density all the while, thus the ...
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1answer
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Curvature, Omega, the Flatness problem, and the evolving shape of the universe
I'm a little confused by this:
http://en.wikipedia.org/wiki/Flatness_problem
Which seems to imply the universe is more curved now than it was soon after the Big Bang. Look at the graph on the right ...
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1answer
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How did the energy/entropy/volume/pressure/temperature relationship exist at the Big Bang and how did it evolve thereafter?
According to the current Big Bang with inflation cosmological model?
I was under the mistaken impression that there was very low volume, very high temperature/pressure, very low entropy and the Big ...
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Why does the homogeneity of the universe require inflation?
They say inflation must have occured because the universe is very homogeneous. Otherwise, how could one part of the universe reach the same temperature as another when the distance between the parts ...
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How to concile flat spacetime and big bang?
After reading How do we resolve a flat spacetime and the cosmological principle? I still remain perplex.
Please excuse my ignorance and try explaining to me :
I thought that basically, when we ...
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2answers
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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 ...
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How is causal patch complementarity compatible with behavior during inflation?
Causal patch complementarity is the conjecture that in de Sitter space with a positive cosmological constant, the states within the causal patch are sufficient to fully describe the universe with the ...
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1answer
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Supermassive Black Holes = expansion origin?
(Sorry, couldn't resist the title)
An article on Physics Today brings news that there is a new record for largest black hole (not) seen in space, some 300 million light-years away. It hints at ...
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Can composite field consists of two fermions cause cosmic inflation rather one scalar field?
Inflation is triggered by one scalar field, can a field composite of fermions do the same in the early universe
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Is eternal inflation and the multiverse compatible with causal patch complementarity?
The argument for eternal inflation is we have some patch of metastable vacuum with positive cosmological constant, and so it expands exponentially a la de Sitter. Most of the patch decays to something ...
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1answer
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Cosmic bubble collision
I'm reading this review right now. The claim seems to be that when you have an expanding "false vacuum", finite size bubbles form due to phase transition (cause by finite action instantons) (which, in ...
