# Inflation & Higgs Particle

1. Feb 18, 2008

### Invariant

Please apologise to my poor English, and I am the bigginner in this field.

I have recently read about The inflation of the universe. It said that The Higgs Particles causes universe expansion with acceleration because of its negative density.
Does it mean it has a negative mass or a negative volume? Can it be possible? Or It has some deep meaning about negative condensation? (In fact I don't even know what it plays role in standard model.) Moreover, the issue said that The Higgs Particle is one of a candidate to be dark matter. Dark matter is pushing space apart? I don't get it.

Thanks a lot.

Last edited: Feb 18, 2008
2. Feb 18, 2008

### cristo

Staff Emeritus
I think that all modern theories of inflation postulate the existence of a field, separate to the Higgs, that drives inflation. To the best of my knowledge, the Higgs field is the field that every particle in the standard model interacts with, and from this interaction obtains its mass.
The inflaton does not have a negative density, but instead has a negative pressure. That is, it has the equation of state p=-rho.
I'm not sure what you mean here. Perhaps you mean dark energy, since that is what we call the energy that is causing the current acceleration of the expansion of the universe. However, I'm pretty sure that dark energy cannot be the Higgs either.

Perhaps you could provide a link to the article you have read?

3. Feb 19, 2008

### cristo

Staff Emeritus
As fate would have it, I came across this paper today which indeed describes a situation in which the inflaton and the Higgs are the same particle. The idea does require a non-minimal coupling between the Higgs and gravity (i.e there are terms in the action which involve multiples of the Higgs scalar field and the Ricci scalar) but there are no new particles required.

4. Feb 19, 2008

### jal

A search on spire for SHAPOSHNIKOV , M resulted in 216 hits.
http://www-spires.slac.stanford.edu/spires/find/hep/www?rawcmd=FIND+a+shaposhnikov+,+m&SKIP=0 [Broken]
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http://lanl.arxiv.org/abs/0710.3755
The Standard Model Higgs boson as the inflaton
Authors: F.L. Bezrukov, M.E. Shaposhnikov
(Submitted on 19 Oct 2007 (v1), last revised 9 Jan 2008 (this version, v2))
We argue that the Higgs boson of the Standard Model can lead to inflation and produce cosmological perturbations in accordance with observations. An essential requirement is the non-minimal coupling of the Higgs scalar field to gravity; no new particle besides already present in the electroweak theory is required.

This provides an extra argument in favour of absence of a new energy scale between the electroweak and Planck scales, advocated in [32].
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http://lanl.arxiv.org/abs/0708.3550
Is there a new physics between electroweak and Planck scales?
Authors: Mikhail Shaposhnikov
(Submitted on 27 Aug 2007)
We argue that there may be no intermediate particle physics energy scale between the Planck mass $M_{Pl}\sim 10^{19}$ GeV and the electroweak scale $M_W \sim 100$ GeV. At the same time, the number of problems of the Standard Model (neutrino masses and oscillations, dark matter, baryon asymmetry of the Universe, strong CP-problem, gauge coupling unification, inflation) could find their solution at $M_{Pl}$ or $M_W$. The crucial experimental predictions of this point of view are outlined.

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Note: The minimum length would be 10^-18.
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jal

Last edited by a moderator: May 3, 2017