Copyright © 1999-2000 David E. Rutherford
All Rights Reserved
Our intention, now, is to present the electric field in its most general
form and to express the field and force equations and energy-momentum tensor
in terms of the generalized electric field. First, we find the general form
of the components of the electric field four-vector,
. Since the
electric field four-vector is a four-gradient it must transform as a covariant
vector, therefore
where the
are the components of the stationary electric field of Eq. (51). Remembering
now that, for a single moving point charge, the components of the potential
four-vector,
, in the unprimed frame are given by Eq. (87), we can write the general
expressions for the components of the electric field four-vector in terms
of the potential field four-vector as
At this point, we would like to introduce a new operator; the four-dimensional analog of the three-dimensional curl of a vector field. This operator we call the "turn" of a four-vector field, which we define as
where
,
here, can be thought of as an arbitrary four-vector field and i,
j, k, and l are unit vectors in the x, y, z, and t
directions, respectively. Another way of writing
is
, where
the operator,
, is not
to be mistaken as the D'Alembertian operator. Using this shorthand, we can
express Eqs. (102) as a single four-vector equation by writing either
or,
equivalently,
.
Copyright © 1999-2000 David E. Rutherford
All Rights Reserved
E-mail: drutherford@softcom.net