Long-time asymptotics of solutions and the modified pseudo-conformal conservation law for super-critical nonlinear Schrödinger equation

Abstract: In this paper, we discuss a class of nonlinear Schr\"odinger equations with the power-type nonlinearity: $(\mathrm{i} \frac{\partial}{\partial t} + \Delta ) \psi = \lambda |\psi|^{2\eta}\psi$ in $\mathbf R^N \times \mathbf R^+$. Based on the Gagliardo-Nirenberg interpolation inequality, we prove the local existence and long-time behavior (continuation, finite-time blow-up or global existence, continuous dependence) of the solutions to the $(H^q)$ super-critical Schr\"odinger equation. The corresponding scaling invariant space is homogeneous Sobolev $\dot H^{q_{crit}}$ with $q_{crit} > q$. Based on the estimates of the quadratic terms containing the phase derivatives used in the paper by Killip, Murphy and Visan \cite[SIAM J. Math. Anal. 50(3) (2018), 2681--2739]{KMV018} we shall study the stability with a stronger bound on the solutions to our problem. Moreover, from the arguments on virial-types presented in the paper by Killip and Visan \cite[Amer. J. Math. 132(2) (2010), 361--424]{KV010}, a modified pseudo-conformal conservation law is proposed. The Morawetz estimate for the solutions to the problem are also presented.