Inflation Definition and 415 Threads

Hey there, i have a question regarding basic inflation and structure formation via linear first order perturbation theory in cosmology. I read through different material (Baumann lecture notes, wikipedia articles, Mukhanov, ...), but at this point i am just confused and find it hard to get an...

A very fundamental doubt. Was inflation expansion of just space or the universe with whatever the state of matter it had?

In the inflationary Big Bang model, our universe is one of the many pocket universes in the multiverse. How can we detect the existence of the other pocket universes? I presumed that all the pocket universes exist in the same physical space. So in principle, they can exert influence on one...

I'm trying to understand more about how our present universe is supposed to be the result of a false vacuum falling to the present vacuum energy. I've been told (correct this if it's wrong), the universe initially underwent a kind of hyperinflation, expanding exponentially due to a much higher...

I am reading some of "Planck 2013 results. XXII. Constraints on inflation." The paper is full of values for various inflationary parameters under various models, with their confidence intervals. For instance, in Table 5 on page 13, the authors report that — for a model including both running of...

I am a high school student and I was searching the inflation theory.When I searched I found that inflation starts a certain time (10-35) how physicists know that 10-35 is the "true" or"right" time ?

According to inflation theory, there first was a scalar quantum field in a false-vacuum (the inflaton). The whole inflationary expansion only got started when the inflaton decayed to its true vacuum. But then people say that the dark energy that causes the universe to expand today, could be...

I read the following passage from a book that does not look correct to me. I understood that the geometry of the universe as far as we can tell is flat to within the error bars of our measurements and that is therefefore either infinite or at least much much larger than our observable patch...

Why have the density perturbations of all lengths a relation to the constant radius c/H? I suppose this is the origin for scale invariance and gaussianity.

Ahoy. Two things ought to be known prior to your reading my terrible post: 1. This is my first post. 2. I don't know very much about this whole business (though time and passion suggests I should) Considering its my first post, let's start at the beginning: Now, I've been reading a whole...

Looking at blogs about the 2-5-15 Planck data release, I noticed a couple of them claiming that it rules out some of the simplest models of inflation, including one called "phi squared inflation". I can't read the specialized characters in physics notations, but I'm figuring this is the same as...

An interesting dimension of the Planck results that can use a thread on its own. http://www.cosmos.esa.int/documents/387566/522789/Planck_2015_Results_XX_Constraints_Inflation.pdf/ Planck 2015 results. XX. Constraints on inflation Preprint online version: February 7, 2015 ABSTRACT We present...

Hi. I am a first-year physics undergraduate student, and really want to become a cosmologist eventually. I was looking into how eternal inflation can generate a multiverse and came across this paper on the arXiv: http://arxiv.org/abs/1408.2249 It claims to have shown that eternal inflation...

If I take a balloon and tie it off prior to blowing it up I have a flaccid balloon with atmospheric pressure both inside and outside the balloon...say 14.7 psi. Now if I blow up the balloon I am working against the elasticity of the rubber and it requires effort to do so. I blow more and more...

I was listening to Brian Cox on Intelligence Squared and he somewhat casually mentioned the general acceptance among physicists of a possibly "infinitely long" period of cold inflation predating the big bang and of the "sudden" stop to this inflation as the source of energy for the big bang...

Hi guys, I am writing a philosophical article about Leibniz's famous question "Why is there something rather than nothing?" and in this context I also discuss scientific theories about the origin of the universe, among these the inflationary theory proposed by Guth. Now since it is going to be...

Recently I watched a lecture on Anti-matter and the Standard Model... ...At one point Dr. Quinn, makes the statement that the CMB is the resulting energy left over from the annihilation of the matter and anti-matter which arose during cosmic inflation (leaving behind only one part in 30 million...

What exactly is this mass inflation instability phenomenon that is said to happen near the inner horizon of black holes? http://jila.colorado.edu/~ajsh/insidebh/realistic.html I got the nutshell of it, but I think I need someone to really explain this.

Several 30-40 minute videos from a great conference on cosmology and the Planck mission results are very much worth watching! The conference was called The Primordial Universe after Planck and was held in Paris 15-19 Dec. On the second day, 16 Dec, there was a debate about what the Planck data...

Theorists have found it difficult to model inflation without having it run hog wild and produce a multiplicity of questionable scientific value. This has bothered Slava Mukhanov who calls it "selfreproduction" and considers it a problem. In September Mukhanov came out with this paper...

Im reading Mukhanov, cosmology foundations, right now (excelent book, by the way). As many others, he gives some reasoning behind the origin of inflation, and there he says that there had not been enough time for the different patches of the universe to get in contact and justify the homogeneity...

I have two questions related to inflation, and wonder if there is an answer to any of them: 1- If there was inflation occurring faster than light at any time, so that the universe's radius is larger than aprox. 14 billion light years, then shouldn´t we be seeing some galaxies more than once...

Constraint on the primordial gravitational waves from the joint analysis of BICEP2 and Planck HFI 353 GHz dust polarization data It seems that the contamination of the BICEP2 signal by B Mode polarised light from galactic dust lanes might explain all the polarisation detected. I was at a...

I was reading about mass inflation inside BH in wiki few years ago (and it did not make any sense to me for multiple reasons) Recently I tried to google this term again - with almost no hits - so this subject (mass inflation) has disappeared from wiki and from science?

The FRW solutions are the basis of the current LCDM cosmological model. They include three possible spatial curvatures, positive, flat and negative. The last two possibilities imply infinite extension for any t>0, while positive curvature would give finite space for finite time by definition...

Hi, I'm looking for an explanation of how eternal inflation leads to the creation of universes in a multiverse. I've read papers and watched videos on the topic, but I can't seem to get my head around it. I've heard words like decay, expansion and inflation in the same sentence to explain the...

I've been trying to understand the whole BICEP story. Here's what I think I understand so far: Inflation produces primordial gravitational waves. During recombination, photons decouple from matter and the CMB is formed. Propagating gravity waves stretch space in one direction and squeeze it in...

There are several threads in the forum on this subject, but I see no satisfying reason that we need inflation. The explanation I typically see is that assuming homogeneity of early universe as an initial condition presents a "fine tuning" problem. Why so much weight on that problem? One could...

The title says a lot about my doubt. I don't know a lot about inflation maths but the idea is that in Inflation, I am seeing that the Cosmological Constant (ie Vacuum Energy) is not Constant in two ways: 1 With time; the Vacuum Energy was larger in the beginning and that triggered Inflation...

I've uploaded a picture of my homework my tutor gave me, and I filled out what I think is to be correct. Basically I figured out what the missing core services inflation rate would be by figuring out what averaged to the total for each column. I'm 100% sure that my approach is incorrect...

Are there any predictions made by the Many-Worlds interpretation of QM that could be ascribed to inflation and or dark energy? In other words, could the hypothetical branching cause our universe to expand?

Hello all, I am trying to design a system with a sensor that can detect when an inflatable is inflated to 2 PSI. I am trying to inflate something small, around 6 liters. I currently have a system that uses a solenoid, the compressed air, and a mechanical timed relay that tells the system when...

I'm asking this just out of curiosity on my part.<grin> When I first heard of cosmic inflation, a long time ago, I went to the local university library to look at papers that made estimates of the total number of e-folds from various models. I'm not an expert in any area of science but I found...

I've thought about this a lot and have tried to find the answer but have been unsuccessful. In the event of the big bang did it inflate through spacetime without effecting it other than warping by mass or did it actually cause the spacetime to flow or move outwards with the inflation?

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"In physical cosmology, cosmic inflation, cosmological inflation, or just inflation is the exponential expansion of space in the early universe. " -Wikipedia Since Inflation Theory specifically talks about 'space', does it mean that inflation didn't have any effects on the temporal dimension...

Hello community! I found this paper and I wanted to share it with you and know what are your thoughts about it. The author is one of the main proponents of Shape Dynamics. http://arxiv.org/pdf/1404.4815.pdf Quantum Inflation of Classical Shapes Tim Koslowski Department of Mathematics and...

A rubber sheet (thickness 0.2mm) was mounted in an open-type Ussing chamber (6mm aperture) such that hydrostatic pressure could be applied to one side and the resulting inflation of the membrane tracked with an OCT instrument (OCT: ocular coherence tomography). From the geometry of the membrane...

I have read about inflation but I really don't understand why it's needed? Could someone explain? The idea is that inflation tells you why the universe is so uniform right? So let's assume the Big Bang starts with a singularity. From this emerges an infinite number of particles - bosons...

HI,... This is my first post here on this forum ... I wonder if anyone here can help me to clarify some concepts to me in the paper of alan guth 2007 named "Eternal inflation and its implications" and this is my question here ... he says in the abstract the following :"Although inflation is...

I read an article that says that inflation at the early stages of the Big Bang explains why the universe is as big as it is today suggesting that if the universe had expanded at the rate it's expanding today it would be no bigger than a full stop. To me this doesn't make sense because I...

Which is the status of cosmic strings? Could they be related to inflation? Which are the most promising scenarios in which inflation arises/could arise in some way from a string cosmology? What do you think of the following papers? http://arxiv.org/abs/hep-th/0507205...

"Cosmic inflation" and singularity Hi. I saw this on Wikipedia: http://en.wikipedia.org/wiki/Chronology_of_the_universe#Planck_epoch Later: If there was no "traditional Big Bang" with inflationary cosmology, would this remove the singularity at the beginning of the universe? If so...

Inflation is often referred to as a period of 'superluminal' or 'faster-than-light' expansion (e.g. see article on Wikipedia and hundreds of research papers on the subject). This has always bugged me. What exactly is superluminal about an inflating universe that does not apply to a non-inflating...

In his popular cosmology book "Que faisiez-vous avant le Big Bang" (sorry, it doesn't seem to have been translated into English) Edgard Gunzig presents a scenario for spontaneous matter production by inflation whereby virtual particle-antiparticle pairs were separated by inflation too far apart...

This paper; http://arxiv.org/abs/1404.4614, Negative running prevents eternal inflation, claims Planck and BICEP2 data favors negative running of the spectral index of curvature perturbations from inflation at the 2 sigma level. It further asserts this is sufficient to preclude eternal inflation.

I found different opinions regarding when inflation was confirmed or when could it be confirmed. Let's write down the facts I know (surely this isn't an exhaustive list): 1) it was proposed in order to solve some problems (horizon, flatness -not sure if monopoles should be included because I...

This is a thread for discussion about papers on LQC and what was published regarding inflation (not counting super inflation), and its relation to the supposedly observed gravitational waves by BICEPS and others experiments. I will post just a few papers here...

Okay, I will be the one in the class that asks the questions that some of us are afraid to ask but still want to know. How could the light from recombination, which occurred about 380K years after the Big Bang, interact with the gravitational waves generated from inflation, which occurred...

So this rumor over the detection of primordial B-modes has got me thinking. Gravitational waves are caused by perturbances in spacetime by asymmetrical objects. So for them to travel, they have to be propagated by something: spacetime. The primordial B-modes are supposedly the result of cosmic...