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View Full Version : [graviton/anti-graviton ~ inflation]



wjwbudro
2010-Jul-11, 01:33 AM
Has anyone ever considered a graviton/anti-graviton analog to matter/anti-matter during inflation? I.e. gravity won out in the latter inflation period just as matter won over anti-matter. I'll let others do the pert-charts.

caveman1917
2010-Jul-11, 04:16 AM
Some particles are their own antiparticle. The photon would be an example of this, and so would be the graviton.
Essentially, there's only the graviton. The antigraviton is simply a graviton itself.

Also it is important to understand that while gravitons have been postulated to explain gravity within a quantum mechanical framework, (as of yet) unresolvable problems have arisen in trying to make the theory work.
String theory also posits the existence of gravitons, but as things stand now string theory itself has some problems it must overcome before it can be accepted.

The graviton is still purely hypothetical. The current theory of gravity is general relativity, which doesn't feature gravitons.

ETA: wikipedia has a fairly good article on the graviton here (http://en.wikipedia.org/wiki/Graviton)

AriAstronomer
2010-Jul-12, 09:53 AM
And by some problems, you mean many (before String theory can be accepted).

caveman1917
2010-Jul-12, 03:15 PM
Well i wouldn't claim many in the sense of a lot of independent problems, but this is mostly a subjective qualification. How many do you need before you say 'many' instead of 'some'.
It's more that the some/many problems it has are indeed very 'problematic' ones, you can't readily sweep them under the carpet so to say.

In any case i was merely pointing out that all the instances where gravitons are used are indeed problematic, and the whole concept of a graviton remains hypothetical up to this day.

trinitree88
2010-Jul-12, 04:07 PM
SNIPPET "[QUOTE=caveman1917;1760430]Well i wouldn't claim many in the sense of a lot of independent problems, but this is mostly a subjective qualification. How many do you need before you say 'many' instead of 'some'."
END SNIPPET
caveman. String theory apparently posits approximately 10500 solutions, any of which might possibly be real, but most of which apparently predict nothing after ~ 20 of work on it. I'd say that's a problem. pete

caveman1917
2010-Jul-12, 04:20 PM
Yes it surely is, i was merely saying that is one problem (and there are some other problems too). Besides, I'm not defending string theory here at all. I was merely giving the OP an overview of the instances in which a graviton is used.

It's not that the multitude of solutions (10^500) means string theory has 10^500 problems, the multitude of solutions is simply one problem it is facing.