a4127

editions-traduites
27

A geometrical definition
of anti-matter.

...As
mentioned by Souriau in 1964 in "Géometry and Relativité", Editions
Hermann, chapter VII "La Relativité à Cinq Dimensions" ( the
five dimensional relativity ), page 413, "the inversion of the fifth dimension
corresponds to the charge conjugation".

...It
is true if the anti-matter corresponds to Dirac's definition. Let us give
an a priori geometric definition of anti-matter. We can figure space with
dimensions :
(368)

This can be figured schematically
as follows, with fibered space-time :
(369)

...We
decide that matter's movements correspond to positive z i 's values and anti-matter's
movements to negative ones, which corresponds to :
(370)

It is easy to modify
the group in order to integrate this in it.
(371)

This becomes a four-components
group ( l = ± 1 ) x 2 ( the extended orthochron group owns two connex
components).

The component ( l = +1
) is a sub-group.

...Clearly,
the ( l = - 1 ) elements change the signs of the additional variables. We
decide that it corresponds to matter anti-matter duality, on pure geometric
grounds.

Let :
(380)

Then we can write, in a more compact way :
(381)

l = 1 corresponds
to the orthochron sub-group.
(382)

Introduce what we will call a : " l-commuter " :
(383)

It belongs to the second
component. But any element of this second component can be written :

(384)

go
= glc x go

being an element of the
orthochron component of the group.

Schematically :

(385)

Left : the movement space,
with two half-spaces, corresponding to

(z i >
0) movements ( matter )

and

(z i >
0) movements ( anti-matter )

Between the two the :

z i = 0 movements
( photons ).

...Right,
the four components group. All are orthochron. All movements correspond to
positive energy ( below, momentum space ).

Call the ( l = - 1 )
elements "anti-elements".

We have figured the l-commuter
anti-element.

...Normal
orthochron elements transform a momentum corresponding to a positive energy
movement J1+ into another positive energy movement J2+.

...But
anti-elements transform positive energy matter's movement into positive energy
anti-matter's movement ( J1+ -----> J3+
) in momentum space. The figurative point is in the quarter which corresponds
to anti-matter.

The corresponding paths
are figured in the evolution space
(385b)

The calculation of the
coadjoint action of the group
(386)

on its momentum gives
:
(387)

see :
J.P.Petit and P.Midy : "Geometrization of matter and anti-matter through
coadjoint action of a group on its momentum space. 2 : Geometrical description
of Dirac's anti-matter". Geometrical Physics B, 2 , 1998.

Index Dynamic Groups Theory