Resumen:
It is generally accepted that solutions of so called "free" Maxwell
equations for Q = 0 (null charge density at every point of the whole
space) describe a free electromagnetic field for which flux lines neither
begin nor end in a charge). In order to avoid ambiguities and
unacceptable approximation which have place in the conventional
approach in respect to the free field concept, we explicitly consider
three possible types of space regions: (i) uisolated charge-free" region,
where a resultant electric field with the flux lines which either
begin or end in a charge is zero in every point, for example, inside
a hollow conductor of any shape or in a free-charge universe; (ii)
"non-isolated charge-free" region, where this electric [see (i)] field
is not zero in every point; and (Hi) "charge-neutral" region, where
point charges exist but their algebraic sum is zero. According to
these definitions a strict mathematical interpretation of Maxwell's
equations gives following conclusions: (1) In "isolated charge-free"
regions electric free field cannot be unconditionally understood neither
as a direct consequence of Maxwell's equations nor as a valid
approximation: it may be introduced only as a postulate; nevertheless,
this case is compatible is the existence of a time-independent
background magnetic field. (2) In both "charge-neutral" and "nonisolated
charge-free" regions, where the condition Q = 6 function
or g = 0 respectively holds, Maxwell's equation for the total electric
field have non-zero solutions, as in the conventional approach.However, these solution cannot be strictly identified with the electric
free field. This analysis gives rise to the reconsideration of the freeelectromagnetic
field concept and leads to the simplest implications
in respect to charge-neutral universe.