Dark matter doesn't emit, reflect or absorb light

In article ,
Gary Harnagel writes:
What is the consensus on Robert Foot and mirror matter?
http://arxiv.org/pdf/hep-ph/0308254v3.pdf

Published reference is
http://journals.aps.org/prd/abstract...RevD.69.036001


I'm not an expert on this, but wouldn't mirror matter show up as
baryonic in the CMB results? I suppose mirror matter could account
for half the baryonic matter if the recent "hot gas in galaxy
clusters" results are wrong, but I don't see how it could account for
the non-baryonic dark matter.

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Steve Willner Phone 617-495-7123
Cambridge, MA 02138 USA

On Monday, December 7, 2015 at 2:27:43 PM UTC-7, Steve Willner wrote:

In article ,
Gary Harnagel writes:

What is the consensus on Robert Foot and mirror matter?
http://arxiv.org/pdf/hep-ph/0308254v3.pdf

Published reference is
http://journals.aps.org/prd/abstract...RevD.69.036001


I'm not an expert on this, but wouldn't mirror matter show up as
baryonic in the CMB results?

I guess that would depend upon how and when it would come into existence.
Presently, we have no idea, so the whole concept seems a bit ... um ...
fabricated. But the conservation of symmetry is enticing.

I suppose mirror matter could account for half the baryonic matter if the
recent "hot gas in galaxy clusters" results are wrong, but I don't see
how it could account for the non-baryonic dark matter.

--
Help keep our newsgroup healthy; please don't feed the trolls.
Steve Willner Phone 617-495-7123
Cambridge, MA 02138 USA

If the mirror matter hypothesis were correct, it couldn't account for ALL
of the dark matter since (presumably) there would be a one-to-one match
with normal matter.

Another hypothesis comes from brane theory, but accounting for five times
as much matter external to our brane is also hard to swallow ... but if
there were more than one other brane ...

Paul Steinhardt's ekpyotic theory posits ONE other bane, but why would
there be only one? We ought to have TWO adjacent branes, and if each
brane had its own mirror matter, that would yield four times the mass
in those plus the mirror matter in our brane would give five times as
much mass as what we can observe non-gravitationally.

It is logical to posit only a single brane (ours), but it is illogical
to presume merely two, or merely three, for that matter. One hypothesis
is that "gravitational leakage" across branes has an exponential decrease
the farther away they are.

Gary