HEAVISIDE OPERATIONAL METHOD FOR DELTA-FUNCTION SEQUENCES

Delta function sequences are regular functions approaching the singula r delta function. They represent more realistic physical models for co ncentrated sources than the idealized delta function. It is shown that delta function sequences can be formed in a straightforward manner th rough the Heaviside operational calculus, by defining quasi-differenti al broadening operators and operating on the singular delta function. Different operators and corresponding delta sequences are studied in o ne and three dimensions. Operator approach for removing the singularit y of the Green function is considered as an application.