Cosmological inflation refers to an era of expansion that lasted for approximately $10^{-34}$ seconds, during which the universe expanded by a factor of approximately $10^{26}$ in every direction. This is different from ordinary space expansion and from the acceleration in expansion we experience now and questions tagged by inflation should pertain to this era and not be about the expansion of the universe in general.
Questions tagged [cosmological-inflation]
708 questions
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How can bubble universes collide in eternal inflation?
In eternal inflation, how can bubble universes collide if the space between them is exponentially stretching and moving them further and further away?
Andrea Scaglioni
- 905
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What are some verified "out of sample" predictions of cosmic inflation?
I'm curious about the "out of sample" (forgive me, my background is in data / statistics / machine learning) predictions of the theory of cosmic inflation. By that I mean phenomena that had not been observed prior to the theory's development; i.e.,…
Josh
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Equation of state at the end of inflation
I read that at the end of inflation, while the inflaton is oscillating about the bottom of it's potential (before it decays), the universe may be treated as matter dominated (e.g. $w=0$; $a\propto t^{2/3}$).
From what I read, this was stated…
Bob
- 1,709
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Why is it said that a random energy distribution in the early universe is more natural than a uniform one?
From Wikipedia:
The horizon problem is the problem of determining why the Universe appears statistically homogeneous and isotropic in accordance with the cosmological principle. For example, molecules in a canister of gas are distributed…
JeneralJames
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How would we falsify Inflation Theory?
What experimental results would falsify inflation theory?
Simply put, inflation seems antithetical to good science theory.
A process that starts at exactly the right time, is of exactly the right magnitude, and lasts for exactly the correct period…
JPattarini
- 1,563
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Initial value dependence of slow-roll inflation
Observables in single field slow-roll inflation (lets assume a monomial potential for simplicity) depend only on the number of e-folds at the pivot-scale, $n_s=1-2/N_*$, $r=8/N_*$ etc.
On the other hand the field equation together with the…
highsciguy
- 594
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1 answer
Stopping inflation, dark energy and switching it on again
Inflation is the current paradigm to explain several big problems of current cosmological models.
My question is simple. Why or what stopped inflation and why is the cosmic acceleration behaviour just like a "little inflation"? Can we guess good…
riemannium
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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 billion years ago because of distance. But not 100%…
user299
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Does the shape of the potential in chaotic inflation have to have this particular form?
(a) represents New inflation ; (b) represents Chaotic inflation.
From what I understand, chaotic inflation means chaotic initial conditions, i.e. different initial inflaton field values in different patches of space.
Why does chaotic inflation have…
parker
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Does Power Law Inflation Lead to Eternal Inflation?
If we have an inflation model with potential $V(\phi) = V_0 e^{-\sqrt{\frac{2}{\lambda}} \frac{\phi}{M_p}}$, where $V_0$ and $\lambda$ are free parameters, does this lead to eternal inflation for $\lambda > 1$?
The slow roll parameter…
jm22b
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What are the significant assumptions in the Inflation theory?
I've tried looking for it,
but there doesn't seem to be any assumption since the theory is based on how things move apart from each other so I can't seem to see assumptions.
K. Cinches
- 11
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Empirical effects of cosmic inflation
Let's imagine that via some contrived mechanism the cosmos entered a new inflationary era, starting right now: Space itself started to uniformly expand faster than the speed of light. Would the effects on Earth be immediate and catastrophic, or…
ybretty
- 11
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What was the diameter of the (observable?) universe at the end of inflation?
One reference says that during inflation, the universe expanded by a factor of 10**26. But I could find no reference to what the diameter was at the beginning. (Perhaps not surprisingly.) Is there an accepted value of the diameter of the universe at…
John Fistere
- 328
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What's the status of Cosmic Inflation after the BICEP2 debacle?
I've read that the gravitational waves supposedly discovered by the BICEP2 observatory last year (and touted as evidence for cosmic inflation) weren't actually gravitational waves, but some sort of local phenomenon.
That being said, what's the…
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Could cosmic inflation restart?
Is it possible for a region of space in our universe to reenter an inflationary state? For example, if a particle accelerator collision of sufficiently high energy recreated conditions under which the early universe experienced inflation, would that…
user34722
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