The Weakly Nonlinear Schrödinger Equation in Higher Dimensions with Quasi-periodic Initial Data

In this paper, under the exponential/polynomial decay condition in Fourier space, we prove that the nonlinear solution to the quasi-periodic Cauchy problem for the weakly nonlinear Schrödinger equation in higher dimensions will asymptotically approach the associated linear solution within a specific time scale. The proof is based on a combinatorial analysis method present through diagrams. Our results and methods apply to {\em arbitrary} space dimensions and general power-law nonlinearities of the form $\pm \mathrm{\mid }u{\mathrm{\mid }}^{2p}u$, where $1\le p\in \mathbb{N}$.