Where is the edge of the universe

[Adrian07]

phinds sorry if you are frustrated with me but I am also frustrated with your answers that don't seem to answer the questions I asked. Basically all I asked for was a simple explanation of where the universe was and how did it get to what we see now. A 3d grid analogy is much easier to understand regarding expansion than a 2d balloon, although this still has severe limitations.
Marcus thanks for input, am I right in thinking that what you are saying at the end of your post is that the rate of expansion should have prevented large scale structures forming, something I have been wondering about re balloon analogy and starting from deflated balloon. Is there a simple explanation anywhere that would make understanding the table you posted easier to understand.

 

[Mordred]

Here is a a wiki article that explains the history of development.
http://en.m.wikipedia.org/wiki/Chronology_of_the_universe

As Marcus pointed out the
calculator can only go so far
back in time. Although his coaxing of it to get back to as far as he did is a handy hidden feature.
During the inflationary epoch the inflation of the universe and high temperatures were too hot for matter to form. The inflation era however only occurred for less than a second.

Matter did not start forming until the universe cooled down the increase is size due to the inflation epoch helped in that cooling down.
Once matter started forming the earliest structures to form were primordial black holes. Wiki referres to these as quasars.

Google universe chronology for more info.

 

[bapowell]

Depending on which inflation model. Most of the ones I am familiar with places it at the beginning stages of the electroweak epoch. Which follows the grand unification epoch

Really? Which ones? Inflation that takes place at the electroweak scale would certainly be considered "low scale" and would be difficult to embed in most extensions to the SM.

 

[Mordred]

Chaotic inflation, false vacuum. Pretty much any QED papers that cover the epochs.

I should have been a little clearer the inflationary epoch is in those models slightly ahead of the electroweak epoch



http://www.nicadd.niu.edu/~bterzic/PHYS652/Lecture_13.pdf



http://physics.uoregon.edu/~jimbrau/astr123/notes/chapter27.html

http://www.fas.org/sgp/othergov/doe/lanl/pubs/00285549.pdf

 

[bapowell]

Chaotic inflation, false vacuum. Pretty much any QED papers that cover the epochs.

Sorry, I'm confused. What QED papers?

The term "chaotic inflation" refers to any inflation model in which the initial field value of the inflaton was highly randomized across the universe. The term "false vacuum" refers to any inflation model in which the field starts out in a region of sufficiently high vacuum energy to drive inflation, with inflation ending when the field evolves to a true vacuum.

These are two very broad categorizations (that are not even necessarily exclusive of each other), so I don't see how these offer examples of electroweak scale inflation. I know it's possible to build a specific model of false vacuum inflation that inflates at the electroweak scale, but there are plenty of models that don't.

I was just wondering if you had any of specific realizations in mind when you made your comment.

 

[Mordred]

http://www.physicsoftheuniverse.com/topics_bigbang_timeline.html

Like I stated false vacuum model and chaotic inflation both place it in that timeline.

Look at lecture 13 in previous post.

I was still gathering papers when your post came in.

the last link of the previous post however shows it later.

I don't know where slow roll
inflation or natural inflation
places it.

This link also shows the early inflation epoch

http://web.njit.edu/~gary/202/Lecture26.html

 

[Mordred]

Took me a bit to find it but Higgs inflation also places at the electroweak epoch

http://arxiv.org/abs/1210.8190

 

[bapowell]

Like chaotic inflation and false vacuum inflation, slow roll inflation is a whole class of models that happen to satisfy the slow roll criteria (e.g. there are chaotic and false vacuum models that are slow roll, so again, these are not exclusive classifications.) It's totally possible to construct slow roll models at virtually any energy scale.

Regarding Higgs inflation, yes, this is what I had in mind as far as specific inflationary scenarios. Since the Higgs is an electroweak degree of freedom, of course Higgs inflation occurs at this scale. You stated that "most" models you know about occurred "at the beginning" of the electroweak epoch, and I'm stating that there is no reason for inflation to preferentially occur here. Inflation works at 10^{16} GeV just as well as it does at the electroweak scale.

The timelines you posted either have inflation occurring at a specific energy scale (which is just wrong) or across a range of scales that is too conservative.

 

[Mordred]

Those articles are based more on particle physics symmetry breaking. More classically the GUT aspects of it. So its natural they would want to refine its energy levels.
Your point is taken in the most models aspect. I should of stated some instead.

 

[bapowell]

More classically the GUT aspects of it.

Right, which is why I'm confused about the emphasis on the electroweak scale. Inflation is generally discussed in the context of particle physics as a GUT-scale phenomenon (the earliest models were based on the SU(5) and SO(10) GUT theories). While these specific approaches didn't pan out, phenomenologically speaking inflation at the GUT scale is still alive well.

 

[Mordred]

You make a good point there, I would be interested in more current papers on GUT. Preference on technical papers.

The particle physics text I'm studying didn't emphasize the timeline of the inflationary epoch. That could explain the "why".

 

[Chronos]

... Once matter started forming the earliest structures to form were primordial black holes. Wiki referres to these as quasars. ...

Evidence for the existence of primordial black holes [PBH] is uncertain [e.g., Primordial Black Holes: Do They Exist and Are They Useful?, http://arxiv.org/abs/astro-ph/0511743] . The evolution of super massive black holes, such as those that power quasars, remains very uncertain. It is fairly evident they were not the earliest structures to form in the universe. CMB studies constrain the number of primordial black holes with masses above 1000 solar to a vanishingly small number [e.g., Effect of Primordial Black Holes on the Cosmic Microwave Background and Cosmological Parameter Estimates, http://arxiv.org/abs/0709.0524] . Contraints on micro PBH's is even tighter [e.g., New cosmological constraints on primordial black holes, http://arxiv.org/abs/0912.5297] . The most distant object yet detected is the galaxy UDFy-38135539 at z=8.6 [re: Ancient giants: on the farthest galaxy at z=8.6, http://arxiv.org/abs/1102.1726] . Other similar candidates include UDFj-39546284 [Photometric Constraints on the Redshift of z~10 candidate UDFj-39546284 from deeper WFC3/IR+ACS+IRAC observations over the HUDF, http://arxiv.org/abs/1211.3105: The Abundance of Star-Forming Galaxies in the Redshift Range 8.5 to 12, http://arxiv.org/abs/1211.6804] The most distant known GRB is GRB 090423 at z=8.1 [GRB 090423 at a redshift of z~8.1, http://arxiv.org/abs/0906.1578] . The most distant quasar yet detected is ULAS J112001.48+064124.3 at z=7.1 [re: A luminous quasar at a redshift of z = 7.085, http://arxiv.org/abs/1106.6088] .

 

[Mordred]

Thanks there is some good articles in that post going to enjoy reading them. In particular the first in regards to PBH'es

 

[Spourk]

http://arxiv.org/abs/1106.6088

"Here we report observations of a quasar (ULAS J112001.48+064124.3) at a redshift of 7.085, which is 0.77 billion years after the Big Bang."

Pretty awesome, this is.