ABSTRACT

Theorem 9.95 Consider the Cauchy problem (1) for u0 ∈ L2ρ∗(IRN ) and u0 = 0. Then, there exists a finite integer l ≥ 0 and a function ϕl(y), such that, as t → +∞,

u(x, t) = t− N+l 2m

[ ϕl (

) +O

( t−

)] (90)

uniformly on compact sets in y = x t1/2m

, where ϕl(y) is a nontrivial superposition of extended eigenfunctions {ψβ, |β| = l} of B from the corresponding finite-dimensional eigenspace.