ON FUNDAMENTAL SOLUTIONS OF OPERATORS OF PRINCIPAL AND NONPRINCIPAL TYPES

Using integrals in complex space,more precisely,inte-grals similar to Hoermander's step integrals,in this paper weconstruct global fundamental solutions for some linear partialdifferential operators(1.p.d.o)with variable coefficients,in-cluding some operators of principal type and non-principal typewith higher multiple characteristics.