ON THE INSTA BILITY OF GROUND STATES FOR A GENER ALIZED DAVEY-STEWA RTSON SYSTEM

摘要

In this paper,we give a simpler proof for Ohta’s theorems[1995,Ann.Inst.Henri Poincare,63,111;1995,DifF.Integral Eq.,8,1775]on the strong instability of the ground states for a generalized Davey-Stewartson system.In addition,a sufficient condition is given to ensure the nonexistence of a minimizer for a variational problem,which is related to the stability of the standing waves of the Davey-Stewartson system.This result shows that the stability result of Ohta[DifF.Integral Eq.,8,1775]is sharp.