Re: Properties of Dark Matter

From: Uncle Al (UncleAl0_at_hate.spam.net)
Date: 09/23/04 

Date: Thu, 23 Sep 2004 09:46:56 +0000 (UTC)

physsist wrote:
>
> Hi
> I've been wondering if anyone has looked at the observational
> constraints on the properties of Dark Matter.
>
> For example, if Dark Matter had its own equivalent of
> electromagnetic or nuclear forces, it might be able to form atoms
> which could clump together to form massive bodies. We would notice the
> gravitational effects if one of these passed through the earth.
>
> Even if DM particles had no interaction with each other it would
> be possible for them to be trapped in the gravitational field of the
> earth or moon, giving these bodies an anomalysly large mass.
>
> And if they had some interaction with each other we might observe
> mysterious increases or decreases in the masses of celestial bodies.

http://arxiv.org/abs/astro-ph/0403292
http://arXiv.org/abs/astro-ph/0310723
 WMAP + Sloane Digital Sky Survey
http://arxiv.org/abs/hep-ph/0404175
 Dark matter candidates
<http://nedwww.ipac.caltech.edu/level5/March01/Carroll/frames.html>
 Carroll on what it all means.

Dark matter must have no electromagnetic, Strong, or Weak interactions
at all with ordinary matter (e.g., scattering) or photons or it would
be screamingly detectable. Dark matter must be gravitationally bound
only and have no binding or other interactions with itself (e.g.,
cooling by radiation emission) or it would not form the uniform
spherical distribution necessary to curve fit visible matter
distribution in spiral galaxies persistent over all visible time
(large red shifts).

A suitable dark matter candidate would be the neutralino that is
safely undetectable even in principle. Theory that cannot be
empirically challenged is weak. 

-- 
Uncle Al
http://www.mazepath.com/uncleal/
 (Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz.pdf

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