The inflaton: a hypothetical scalar particle

[bryanmcc]

Chronos mentioned a hypothetical particle called the inflaton in the out-of-control scalar weapon thread, to wit:

Finally, a even more hypothetical particle called the inflaton might be a scalar, and I can say with high confidence that if they exist, a stream of them would be very destructive. However, as yet we havve very little clue what the inflaton might even be, much less how to create them, and there haven’t been any inflatons in the Universe for approximately 99.9999999999999999999999999999999999999999999999999999999999% of the lifespan of the Universe. I therefore speak with some confidence when I say that current conditions would not allow for the creation of inflatons, whatever they are.

This piques my curiosity. Can anyone tell me more about these particles? Why are they hypothesized to exist? What are their properties? Why would they be destructive to normal matter?

[bryanmcc]

Come on, doesn’t anyone know anything about these things?

[t-keela]

In an attempt to explain why the universe is still expanding at even a greater rate than in the past. Scientists have been “on the lookout” for dark matter and energy.

One of these theories involves a hypothetical scalar field of dark energy called the inflaton. Supposedly provided the force for the Big Bang.
I could attempt the physics but this cite does a better job than I ever could.

http://www.aip.org/pt/vol-56/iss-4/p10.html

BTW: IIRC it predicts a flat universe that recycles bang/crunch/bang etc.

[bonzer]

Inflatons are just the particle manifestation of the hypothetical scalar field that’s supposed to drive inflation.

Backing up a bit, this is analogous to the Higgs particle and spontaneous symmetry breaking (SSB) in the Standard Model. You have a field that interacts with itself such that symmetric configurations of it are unstable under small perturbations, with the result that the field always evolves from the symmetric situation to an unsymmetric one. Thereby breaking the symmetry.
In the simplest such models you can think of what’s happening at a particular point in space in terms of a classical “Mexican hat” potential. Call the field strength at this point phi. Then if you plot out the energy of the field against this field strength then you get a shape with a hill in the middle and valleys on either side. Start with phi=0. This is the top of the hill and so everything’s symmetric. But it’s energetically favourable for the field to roll down into one of the valleys. So it does so. Now phi=/=0 and the situation is not symmetrical.
In inflationary models, this process happens throughout space during the early stages of the Big Bang. The energy released by “rolling down all those hills” is what drives events.

Over the years the shape of the potential and the identity of the inflaton field have been played around with. So recent ideas are different in the details, but the basic ideas have remained much the same.