Scattering and blow-up solutions to nonlinear Schr\"odinger equation beyond the threshold
In this paper, we consider nonlinear Schr\"odinger equation. Duyckaerts--Roudenko [Comm. Math. Phys. 334 (2015), no. 3, 1573--1615] investigated time behavior of solutions to the equation, whose mass-energy is greater than that of the ground state. We revisit the results and show by using the action. Moreover, we apply it to other equations without scale invariance.