Decay And Blow-up Of Solutions For A Class Of Higher Order Parabolic Equations

In this thesis,we consider the following problem where Ω ? Rn(n ≤ 3)is a bounded domain,with smooth boundary ?Ω.p,q are constants such that q>p>4.In this thesis,we use the potential well method to study.We prove the existence of global weak solution by using Galerkin method and monotone operator theory.At low initial energy(J(u0)=d,I(u0)>0),we find an estimate of the decay of the solution,and when I(u0)<0,we find that the solution blows up in finite time.