Rd. Gregory, HELMHOLTZS THEOREM WHEN THE DOMAIN IS INFINITE AND WHEN THE FIELD HASSINGULAR POINTS, Quarterly Journal of Mechanics and Applied Mathematics, 49, 1996, pp. 439-450
A direct proof, based on classical analysis, is given to extend Helmho
ltz's fundamental theorem of vector analysis to cases in which the dom
ain is infinite and/or the field u(r) has isolated singular points. No
restriction whatsoever is placed upon the growth of u(r) as \r\-->inf
inity, or as the singular points are approached, Consequently all repr
esentation theorems dependent upon Helmholtz's theorem are also freed
from such restrictions.