In order to analyze the singularities of a power series P (t) on the boundary of its convergent disc, we introduced the space Ω(P ) of opposite power series in the opposite variable s=1/t, where P (t) was, mainly, the growth function (Poincaré series) for a finitely generated group or a monoid [S1]. In the present paper, forgetting about that geometric or combinatorial background, we study the ...

In this paper, He’s homotopy perturbation method is applied to solve linear Schrodinger equation. The method yields solutions in convergent series forms with easily computable terms. The result show that these method is very convenient and can be applied to large class of problems. Some numerical examples are given to effectiveness of the method.