2011/10/17 by Bonckaert, P., Verstringe, F.
#34C20 #37C10 #37G05 #Dynamical Systems (math.DS) #FOS: Mathematics
paper · doi:10.48550/arxiv.1110.3810
We explore the convergence/divergence of the normal form for a singularity of a vector field on \Cn with nilpotent linear part. We show that a Gevrey-α vector field X with a nilpotent linear part can be reduced to a normal form of Gevrey-1+α type with the use of a Gevrey-1+α transformation. We also give a proof of the existence of an optimal order to stop the normal form procedure. If one stops the normal form procedure at this order, the remainder becomes exponentially small.