Higgs Field

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Main Question or Discussion Point

I assume that before the Big Bang, there was no Higgs Field, since there was no universe for it to fill.
I assume that at the moment of the Big Bang, it began to seep into every corner of the expanding universe and was carried by inflation, that is, moving faster than the speed of light by the expanding universe.
I assume that the energy density of the Higgs Field decreased enormously as it expanded into larger and larger volumes of space, presumably decreasing the mass of particles with time.
If all of the above assumptions are correct, what effect did the decreasing mass of particles have on the evolution of the universe?
 

Answers and Replies

  • #2
PeterDonis
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I assume that before the Big Bang, there was no Higgs Field, since there was no universe for it to fill.
You assume incorrectly. The Big Bang is not an "initial singularity". It is simply the hot, dense, rapidly expanding state that is the earliest state of the universe for which we have good evidence. Our current best fit model is that this state occurred at the end of inflation.

I assume that at the moment of the Big Bang, it began to seep into every corner of the expanding universe and was carried by inflation, that is, moving faster than the speed of light by the expanding universe.
You assume incorrectly. Any quantum field (including the Higgs and every other field) exists at every point of spacetime. There is no need for it to "seep" anywhere.

I assume that the energy density of the Higgs Field decreased enormously as it expanded into larger and larger volumes of space, presumably decreasing the mass of particles with time.
You assume incorrectly. The vacuum expectation value of the Higgs field has been the same ever since the electroweak phase transition, as have the masses of particles that derive their masses from the Higgs field.

If all of the above assumptions are correct
Which they aren't, so your question is not well posed. See above.
 
  • #3
kimbyd
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As PeterDonis pointed out, you seem to be under the misconception that fields may or may not fill space. This isn't the case.

In quantum field theory, a field merely exists. Each field that exists may take on different values. Those values are quantized into discrete units. Those discrete units are particles. For example, the electron field describes all electrons which exist. At any given location, there may or may not be any electrons. The field value at that location tells you how many electrons are there. The field exists whether or not there are any electrons: it represents the potential for electrons to exist, not whether they actually do.

Thus the field is a representation of the laws of physics.
 
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Oh, but....
https://arxiv.org/abs/1707.06922 and in particular:
We point out that the expansion of the universe leads to a cosmological time evolution of the vacuum expectation of the Higgs boson. Within the standard model of particle physics, the cosmological time evolution of the vacuum expectation of the Higgs leads to a cosmological time evolution of the masses of the fermions and of the electroweak gauge bosons while the scale of Quantum Chromodynamics (QCD) remains constant.
 
  • #5
PeterDonis
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Oh, but....
First, this paper does not appear to have been peer reviewed. It does not appear to me to be describing our current best model, but the author's own speculation.

Second, the hypothetical change in the vacuum expectation value of the Higgs field that this paper is describing would have taken place since the electroweak phase transition, which is well after the end of inflation. Also, of course, the paper is certainly not describing "seepage" of the Higgs field anywhere. So even if this paper's claims prove to be correct, they do not support any of the three assumptions you made in your OP.
 
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The more that I read about this subject, the more humble I become. Have a look at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4247394/ if you want to consider related explanations/speculations, albeit 3 years old, that suggest the evolution of the Higgs Field has had tremendous effects.
Thanks to both of you for replying.
 
  • #7
PeterDonis
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The more that I read about this subject, the more humble I become.
There are certainly a lot of unknowns remaining about the Higgs, all of which, as far as I can tell, fall under the general heading of: the Standard Model that we have developed based on experiments at energies accessible to us is probably a low energy effective field theory, and there are multiple possibilities for what the underlying more fundamental theory at the next level down might be, and these include multiple possibilities for how the Higgs sector works.
 
  • #8
kimbyd
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First, this paper does not appear to have been peer reviewed. It does not appear to me to be describing our current best model, but the author's own speculation.

Second, the hypothetical change in the vacuum expectation value of the Higgs field that this paper is describing would have taken place since the electroweak phase transition, which is well after the end of inflation. Also, of course, the paper is certainly not describing "seepage" of the Higgs field anywhere. So even if this paper's claims prove to be correct, they do not support any of the three assumptions you made in your OP.
It is peer-reviewed, as near as I can tell, but I do think the statements made in the abstract are far, far too strong:
https://link.springer.com/article/10.1140/epjc/s10052-017-5324-5

A more accurate representation of the work would be that it suggests that there might be a relationship between the expansion and the Higgs vacuum field value, and then tries to show some of the consequences of that. They show that if there is some dependence, it's incredibly tiny using ground-based experiments. My bet is that you could get vastly stricter constraints on this model by using measurements of light-element abundances.
 
  • #9
Garth
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First, this paper does not appear to have been peer reviewed. It does not appear to me to be describing our current best model, but the author's own speculation.
It is published in a peer reviewed journal here:

Cosmological evolution of the Higgs boson’s vacuum expectation value

From that journal's webpage:
The European Physical Journal C Particles and Fields
ISSN: 1434-6044 (Print) 1434-6052 (Online)
Description
The European Physical Journal C (EPJ C) is an open-access single-blind peer-reviewed journal, APCs completely covered by SCOAP3 (scoap3.org) and licensed under CC BY 4.0. EPJ C presents new and original research results in theoretical physics and experimental physics, in a variety of formats, including Regular Articles, Reviews, Tools for Experiment and Theory, Scientific Notes and Letters. The range of topics is extensive:
Garth
 
  • #10
Oh, but....
https://arxiv.org/abs/1707.06922 and in particular:
We point out that the expansion of the universe leads to a cosmological time evolution of the vacuum expectation of the Higgs boson. Within the standard model of particle physics, the cosmological time evolution of the vacuum expectation of the Higgs leads to a cosmological time evolution of the masses of the fermions and of the electroweak gauge bosons while the scale of Quantum Chromodynamics (QCD) remains constant.
I believe this is simply a sloppy language. "Cosmological time evolution of the vacuum expectation [value]" does not make sense. "Cosmological time evolution of the value" does.

*Vacuum expectation* value does not change, it's the value of the field if you remove all particles from a region of space and thus have a vacuum there.

Value of the field (without "vacuum expectation" part) does change, especially significantly in the early cosmological epochs. For example, it might have been very large everywhere at first. This state is not a vacuum if the field can "roll down" to the lower energy state (IOW: if it's not in a local minimum), but I see that many papers erroneously use the language of "vacuum expectation" value for this case too.
 

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