Re: Anti-matter

[Shawn Kolitch <skolitch@pandora.physics.calpoly.edu>]

Be careful--"antimatter" is conventionally used to describe particles
with ordinary gravitational properties, but which have charges opposite
those of their counterparts (positrons and electrons, for example).
The existence of these particles is inherent in the symmetries of
relativistic QM (the Dirac eqn., in the case of electrons and positrons),
and is predicted by all quantum field theories.  All of these particles
are gravitationally *attractive* just like the rest of us.

However, general relativity does allow the possibility of exotic matter
which is gravitationally repulsive in the Newtonian limit, such as
domain walls and false-vacuum energy.  This is the type of matter on
which most models of inflationary cosmology are based, although its
existence has never been observed and it violates the strong energy
condition (which states that the effective gravitational source term
due to any matter should always be positive).  One consequence of this
violation is that the singularity theorems of GR are no longer valid.
In any case, this matter is normally referred to as "exotic" or
"inflationary", but not as "antimatter".


--Shawn Kolitch.


On Thu, 26 Feb 1998, Prof. John P. Ertel (wizard) wrote:

> By convention, g-field lines for "our kind of matter" are said to go out
> of the source (matter).  Therefor, the field lined for the "other kind of
> matter" would go into that source (anti-matter).
>
>
> On Thu, 26 Feb 1998, John DaCorte wrote:
>
> > Is the gravitational field for anti-matter any different than that of
> > matter?  In other words, if I had two identical "masses", one of matter
> > and one of anti-matter, would the gravitational field for each be any
> > different.  Thanks in advance for any help.
> >
> > John DaCorte

___________________________________________________________________

Dr. Shawn Kolitch			Email: skolitch@calpoly.edu
Department of Physics			Phone: (805) 756-2205
Cal Poly State University		Office: 52-E14
San Luis Obispo, CA  93407
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