2021/06/30 by Soffer, Avy, Wu, Zhao, Yao, Xiaohua
#Analysis of PDEs (math.AP) #FOS: Mathematics #FOS: Physical sciences #Mathematical Physics (math-ph)
paper · doi:10.48550/arxiv.2106.15966
This paper is devoted to study the time decay estimates for bi-Schrödinger operators H=Δ2+V(x) in dimension one with decaying potentials V(x). We first deduce the asymptotic expansions of resolvent of H at zero energy threshold without/with the presence of resonances, and then characterize these resonance spaces corresponding to different types of zero resonance in suitable weighted spaces Ls2(R). Next we use them to establish the sharp L1-L^∞ decay estimates of Schrödinger groups e-itH generated by bi-Schrödinger operators also with zero resonances. As a consequence, Strichartz estimates are obtained for the solution of fourth-order Schrödinger equations with potentials for initial data in L2(R). In particular, it should be emphasized that the presence of zero resonances does not change the optimal time decay rate of e-itH in dimension one, except at requiring faster decay rate of the potential.