Questions tagged [cosmological-inflation]

Questions regarding the phenomenon in the early universe characterized by an extreme expansion of space.

Filter by
Sorted by
Tagged with
3 votes
1 answer
166 views

Have astronomers taken into account the fact that red-shifted light from far-away stars is also very old when studying the expansion of the universe?

I am aware that Hubble discovered that the further away a galaxy is the greater its redshift. What I don't understand is how astronomers can be sure that distant objects are still moving at greater ...
user avatar
1 vote
0 answers
22 views

Does cosmic inflation spawn from empty space, or vice versa?

In the eternal inflation model supported by Sean Carroll and others, the basic premise is that inflation is continuous in places across an infinite cosmos, and that bubble universes (like our own) are ...
user avatar
1 vote
0 answers
97 views

How can the universe be flat?

In each video I see on Alan Guth or anyone explaining cosmic inflation and how it solved the flatness problem, it is said that "the repulsive effect of gravity thus change how omega evolves and ...
user avatar
  • 91
1 vote
0 answers
58 views

How did cosmic inflation even occur?

I wanted to ask this question that which inflation model shall i believe? Following below will be MY UNDERSTANDING (MAY NOT BE CORRECT) OF IT: I read "A Brief History of Time" and in chapter ...
user avatar
  • 91
3 votes
1 answer
87 views

Why is cosmological redshift treated as a different phenomenon to doppler redshift? [duplicate]

I understand that the expansion of the universe causes unbound structures to move apart from each other. This means that unbound structures have negative relative momentum due to universal expansion. ...
user avatar
  • 191
1 vote
0 answers
124 views

Cosmic inflation was faster than light. Why would a false vacuum decay bubble only expand at the speed of light?

I have been reading about cosmic inflation: the initial step in the formation of our universe when space/time inflated to fill whatever preceded it. I understand that this inflation happened faster ...
user avatar
  • 303
0 votes
0 answers
34 views

Is the number of galaxies in the observable universe increasing? [duplicate]

Is the number of galaxies in the observable universe increasing? Are more and more galaxies coming into view? Or is the number decreasing? If it's increasing then when will it reach a maximum? If it's ...
user avatar
8 votes
1 answer
123 views

How distant were the furthest currently-observable cosmic events when their currently-observed radiation was emitted?

(Edited for clarity. Thanks to James K and Connor Garcia.) This question about the most distant, observable cosmic objects made me wonder if we know the distance that was between us and them at the ...
user avatar
1 vote
0 answers
42 views

How much does the Higgs field contribute to the energy of empty space?

The Higgs field was not spontaneously broken when the universe was young and hot (like I am not...:)). At the very high temperature that existed back then, the Higgs' energy of the Higgs field was non-...
user avatar
2 votes
0 answers
62 views

How do we know or predict which particles were present before Big Bang Nucleosynthesis occurred?

I'm reading Carroll and Ostlie's "An Introduction to Modern Astrophysics". In the BBN section, they describe that the universe contains a mixture of photons, electron-positron pairs, and ...
user avatar
  • 1,051
5 votes
1 answer
164 views

Understanding better the factors on $C_l$ in Angular power spectrum and Relation with Matter power spectrum

I am looking for an explanation on the angular power spectrum. I found this extract that is interesting but not fully understood for me (I will cite the step that I didn't understand) "what is ...
user avatar
0 votes
0 answers
82 views

Accuracy of the Inflation theory

In the Inflation theory, it said that the Inflationary epoch has happened $10^{-32} \,\mathrm{s}$ after the Big Bang, and I cannot find anything related to how this number was calculated and how ...
user avatar
2 votes
1 answer
103 views

What's the furthest distance that something could travel and eventually come back to Earth?

Imagine u shoot a photon into the sky at a mirror far away in space, and you want the photon to bounce off the mirror and eventually come back to you. Considering the cosmological constant, what's the ...
user avatar
0 votes
2 answers
161 views

Why can't we point the centre of the universe from inflation graph we see?

This question is not about whether it makes sense to have a centre of the universe or not instead, it's about the inflation graph we used to see while describing the Big Bang. From the inflation graph ...
user avatar
2 votes
2 answers
155 views

What powered the Big Bang?

According to the first law of thermodynamics, law of conservation of energy states, The total energy of an isolated system is constant; energy can be transformed from one form to another, but can be ...
user avatar
3 votes
1 answer
339 views

What happened before, Big Bang or inflation?

I always thought that the cosmic inflation happened after the big bang (10-36 sec) and lasted for a very tiny fraction of time). Now, I recently came across a couple of articles (links below) claiming ...
user avatar
  • 71
3 votes
1 answer
88 views

Was Guth inflation propelled by what we now call "Dark Energy"?

The more powerful our telescopes become, the more we are able to see earlier and earlier remnants of Guth Inflation. Assuming that it makes sense to associate a location, BB, in space-time where the ...
user avatar
3 votes
1 answer
283 views

Time dilation due to the expansion of the universe

This is not a homework question. I want some help in being able to clearly perceive the expansion of the universe and the consequences thereof. We know that the universe is expanding in an ...
user avatar
1 vote
0 answers
46 views

Probability of collision of another bubble universe with our universe

This is rephrased from a previous question and expanding on it. Considering the model of an "inflating" universe which extends infinitely in past (and possibly future) time, constantly creating new ...
user avatar
11 votes
2 answers
887 views

Are there ways to estimate size of the "whole universe"?

Words escape me, but by "whole universe" (I think) I mean everything that's spatially connected to the observable universe in a conventional sense. If there is a better term for it, please let me know!...
user avatar
  • 31.4k
3 votes
0 answers
100 views

The nature of cosmological inflation — unfolding dimensions?

While the paradigm of cosmological inflation is well established, the nature of the inflation is not known and is tackled by introduction of a hypothetical "inflaton" field. I was wondering if there ...
user avatar
5 votes
2 answers
134 views

What is the difference between the way light travels in a gravitational field and the way it travels through an expanding universe?

A photon is travelling through space. As it travels, the space through which it travels is expanding Does this describe A - a photon travelling from a distant galaxy to earth B - a photon travelling ...
user avatar
  • 191
1 vote
1 answer
238 views

Time-frame regarding cosmic expansion and the bound state of the Virgo Cluster

Due to accelerating cosmic inflation, other galaxies and galaxy clusters will eventually race toward the Hubble horizon apparently away from us, placing them effectively out of our sphere of influence....
user avatar
1 vote
1 answer
207 views

Can eternal inflation and gravity explain dark energy?

First of all, I have absolutely no background in astronomy and physics. I just watch a lot of "i-hope-scientific" youtube channels talking about physics and astrophysics and I can kind of follow the ...
user avatar
2 votes
2 answers
1k views

What explains the existence of energy/matter if it cannot be created or destroyed?

If the energy/matter that was contained in the singularity before the Big Bang had always existed, and if it’s true that energy/matter cannot be created or destroyed, then what explains its existence?
user avatar
0 votes
1 answer
110 views

Fundamental axioms in LCDM

What are the axioms (if any) behind the LCDM model of cosmology? NB: axioms, not postulates (e.g., inflation)
user avatar
2 votes
1 answer
66 views

Where can I find source data for the graph of metric expansion over time, as shown in this ESA web page?

This web page from ESA/Hubble, shows the size of the universe over time. (I know that "size of the universe" is a gross simplification and open to multiple definitions and ambiguity, but this kind of ...
user avatar
  • 924
3 votes
2 answers
215 views

BIg Bang Happened everywhere

According to the Friedmann equations big bang happened everywhere, but if we account for inflation theory, big bang did not happened everywhere. How ? Anyone please explain. Please see the video for ...
user avatar
  • 499
2 votes
1 answer
187 views

How does inflation justify the nonexistence of magnetic monopoles?

It is said that inflation justifies that magnetic monopoles don't exist. Can anyone explain how inflation theory explains the non existence of magnetic monopoles?
user avatar
  • 499
4 votes
2 answers
130 views

Does Flat Universe mean even distribution?

I've read through all the other related answers to "flatness" questions but I need a bit more clarification. I understand that a triangle in a 2D universe would not equal 180 degrees in both a closed ...
user avatar
3 votes
1 answer
1k views

What will the universe be like in a googolplex years time?

It will be cold and dark in 10^(10^100) years. What else can be said of the state of things in the far distant future? Will everything have fallen into supermassive black holes and then radiated ...
user avatar
3 votes
1 answer
81 views

Does wavelength affect redshift caused by the metric expansion of space?

Does wavelength play a role in cosmological redshift? Do we see certain wavelengths affected less by expansion or notice any delay in arrival of certain wavelengths? How accurate are any observations?...
user avatar
  • 513
3 votes
1 answer
156 views

Could the expansion of universe be a side effect of gravity?

Could the expansion of universe be a side effect of gravity? I mean maybe gravity "attracts things" at a "small" distances and repells them at "larger" distances? Do we have any theory/hypothesis/...
user avatar
3 votes
4 answers
418 views

What is the acceleration for the expansion of the Universe?

I've found that the speed of expansion is about $70\frac{km}{s\cdot 10^{6}pc}$. But what is the acceleration of expansion in terms of $\frac{km}{s^{2}\cdot 10^{6}pc}$ ? I want to know how fast this ...
user avatar
3 votes
0 answers
110 views

What is the difference between Steinhardt's and Neil Turok's cyclic cosmology and Guth's inflationary model and Hartle, Hawking no boundry cosmology?

I have been reading some cosmology and need to ask the experts at this point some specific points. I must admit I am a little confused. There are a few models of the universe and may be necessary at ...
user avatar
0 votes
1 answer
4k views

What are the significant assumption of the Inflation Theory? [closed]

Can it still be considered theory ?, because I can't find it's major or significant assumptions.
user avatar
4 votes
0 answers
205 views

Is cosmic inflation still a hypothesis?

Is Cosmological inflation still considered as hypothesis? Is CMBR evidence not enough?
user avatar
2 votes
2 answers
192 views

Could Dark Energy be a "Cosmic Gravity Background"

Could dark energy (the accelerating expansion of the universe) be the result of gravity from the dense past universe "pulling" outward from all directions? The universe theoretically started out ...
user avatar
  • 3,919
3 votes
1 answer
170 views

Are there expanding-universe cosmological models that do not include inflation?

I'm happy that the universe is expanding, because we have good scientific evidence in the form of galactic redshift. The Wikipedia Hubble's law article gives what I think is a fair explanation of that....
user avatar
2 votes
1 answer
104 views

Could the accelerating expansion of universe inidicate we are surrounded by "denser" space? [closed]

I'm quite novice about all this, only have read some vulgarization books and sites, but I wonder: could all the observable universe be falling outwards on some non-observable, more compact kind of ...
user avatar
  • 1,392
3 votes
2 answers
363 views

Is the Big Bang inflation caused by Dark Energy

The rate of expansion of the universe after the Big Bang is described as Inflation. It is stated as being initially very fast then slowed. But the expansion is still continuing. Some say expansion is ...
user avatar
  • 31
2 votes
1 answer
365 views

Is the M81 group bound to the Local group?

Andromeda and the Milky Way are set to collide in 4bn years. Will the Local Group collide with M81, and what about further away groups? if so, when?
user avatar
3 votes
1 answer
150 views

Standard Big Bang model and space curvature

Why it is said that in standard Big Bang model space curvature grows with time when the Universe expands? My intuition is that it should be the opposite. I saw this in a book talking about the ...
user avatar
-1 votes
1 answer
197 views

Why is the CMB not simply travelling parallel to us? [closed]

When we look to the distant farthest reaches of the universe we see light that was emitted at the big bang 14 billion years ago. But the universe was tiny back then so that light, which is only ...
user avatar
4 votes
2 answers
433 views

How could universe inflate itself out of the very dense and curved early spacetime? Could it happen in a black hole too?

Wasn't spacetime as much curved as a black hole directly after Big Bang, because mass was so densly packed? Wasn't everything like an event horizon and how could things expand across it? Could ...
user avatar
  • 10.8k
1 vote
2 answers
150 views

Was time different before the great inflation?

In time different during the first second after Big Bang than it is now? Inflation had a dramatic effect on space, and spacetime is one thing. Was the properties of time affected too? Curved spacetime ...
user avatar
  • 10.8k
1 vote
1 answer
97 views

Intuitive explanation for why the universe is flat

I went through Prof. Hitoshi Murayama's online lecture where he describes why the universe is flat. One of the evidences for a flat universe is the evenness of CMB radiation on all directions. My ...
user avatar
  • 151
1 vote
1 answer
310 views

Is nucleosynthesis responsible for the expansion of the universe?

Is it just a coincidence that the two major expansionary periods occur close to periods of nucleosynthesis? Big Bang nucleosynthesis occurred very close to the inflationary period. Supernova and ...
user avatar
4 votes
1 answer
284 views

How can cosmic inflation make an infinite universe homogeneous?

As it is explained in this video, one of cosmic inflation's observable effects is the homogeneity of our universe. Inflation allows two points on the different sides of the observable universe to be ...
user avatar
  • 71
1 vote
1 answer
72 views

Light that travels eternally because of inflation?

What happens with electromagentic waves that are emitted into intergalactic space, but reach not any object because of inflation? Lets assume that photon A and photon B are emitted. Photon B hits ...
user avatar