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The Question
(Submitted July 26, 2006)
Since string theory implies up to 11 dimensions, could dark matter be
gravitons leaking from other dimensions into ours?
The Answer
Actually, that's exactly one possibility that's being explored by
brane-world theorists. Of course, the jury is still out on brane-world
theories....
From the Cornell Chronicle:
http://www.news.cornell.edu/stories/March06/Tye.brane.ws.html
"In brane-world theory, the ends of strings are anchored in our brane, so
the particles we see can only move within the brane. But the particles that
carry the gravitational force, known as gravitons, are closed strings --
little Cheerios -- and can "leak" out of the brane. This explains why gravity
is much weaker than the electromagnetic force and the strong and weak nuclear
forces. It also offers a possible explanation for the "dark matter" that
astronomers need to explain why the mass of the universe doesn't agree with
the observed objects. Dark matter could be in an adjacent brane, with its
gravitons leaking into ours."
We hope this helps!
Barbara & Ilana
For Ask an Astrophysicist
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