Special Session 34: Recent advances on integrable systems and related topics

Point of constancy of the periodic linear Schr$\mathrm{\ddot{o}}$dinger equation
Jing Kang
Northwest University
Peoples Rep of China
Co-Author(s):    
Abstract:
In this talk, we investigate the points of constancy in the piecewise constant solution profiles of the periodic linear Schr$\mathrm{\ddot{o}}$dinger equation with step-function initial data at rational times. We characterize all points of constancy of the solution $u$ and the square of the modulus $|u|^2$ of $u$, respectively. We employ number theoretic techniques, including quadratic Gauss sums and half-Gauss sums. These results establish an intriguing connections between the revival phenomena of dispersive evolution equations on a periodic domain and the classical number theory.