Cauchy problem for hyperbolic operators with triple characteristics of variable multiplicity
Cauchy problem for hyperbolic operators with triple characteristics of variable multiplicity
We study a class of third order hyperbolic operators P in G=Ω∩{0≤t≤T},Ω⊂ℝ n+1 with triple characteristics on t=0. We consider the case when the fundamental matrix of the principal symbol for t=0 has a couple of non vanishing real eigenvalues and P is strictly hyperbolic for t>0. We prove that …