%0 Journal Article %T An improved version of Poincare-Dulac theorem for improved nilpotent normal forms %A J. Mikram %A F. Zinoun %J International Journal of Mathematical Analysis %D 2013 %I %X An improved version of the well-known Poincare-Dulac¡¯s normal form theoremis first proposed. It is shown that, for a nonlinear vector field, a normal formnear a singular point can always be chosen so that the number of nonlinearcomponents is at most equal to the number of Jordan blocks in the normalizedleading matrix, thus leading to the ¡°simplest¡± form in which a formal vectorfield can be written near a singular point. Within this scope, a generalizationto any dimension of an important result on normal forms of nilpotent systemsis given. This is the main result of the paper. %K Poincare-Dulac Normal Form %K Jordan Normal Form %K Nilpotent Systems %K Lie Series %U http://www.m-hikari.com/ijma/ijma-2013/ijma-17-20-2013/zinounIJMA17-20-2013.pdf