vix.ing · top · new · best · stats · spec

Pointwise estimates for the fundamental solutions of higher order Schrödinger equations in odd dimensions II: high dimensional case

2024/08/28 by Cheng, Han, Huang, Shanlin, Huang, Tianxiao +1
#Analysis of PDEs (math.AP) #FOS: Mathematics

paper · doi:10.48550/arxiv.2409.00117

Abstract

In this paper, for any odd n and any integer m≥1 with n>4m, we study the fundamental solution of the higher order Schrödinger equation i∂tu(x,t)=((-Δ)m+V(x))u(x,t), t∈ ℝ, x∈ ℝn, where V is a real-valued C(n+1)/(2)-2m potential with certain decay. Let Pac(H) denote the projection onto the absolutely continuous spectrum space of H=(-Δ)m+V, and assume that H has no positive embedded eigenvalue. Our main result says that e-itHPac(H) has integral kernel K(t,x,y) satisfying |K(t, x,y)|≤ C(1+|t|)-((n)/(2m)-σ)(1+|t|-(n)/(2 m))(1+|t|-(1)/(2 m)|x-y|)-(n(m-1))/(2 m-1), t≠0, x,y∈ℝn, where σ=2 if 0 is an eigenvalue of H, and σ=0 otherwise. A similar result for smoothing operators H^\fracα2me-itHPac(H) is also given. The regularity condition V∈ C(n+1)/(2)-2m is optimal in the second order case, and it also seems optimal when m>1.

Related