S. Ouchi, Growth property and slowly increasing behaviour of singular solutions of linear partial differential equations in the complex domain, J MATH JPN, 52(4), 2000, pp. 767-792
Consider a linear partial differential equation in Cd+1 P(z,partial derivat
ive )u(z) = f(z), where u(z) and f(z) admit singularities on the surface {z
(0) = 0}. We assume that \f(z)\ less than or equal to A\z(0)\(c) in Some se
ctorial region with respect to to. We can give an exponent gamma* >0 for ea
ch operator P(z,partial derivative) and show for those satisfying some cond
itions that if For All epsilon > 0 There ExistsC(epsilon) such that \u(z)\
less than or equal to C-z exp(epsilon \z(0)\(-gamma*)) in the sectorial reg
ion, then \u(z)\ less than or equal to C\z(0)\(c') for some constants c' an
d C.