On the Gross-Pitaevskii evolution linearized around the degree-one vortex
Jonas Luhrmann, Wilhelm Schlag, Sohrab Shahshahani
TL;DR
The paper analyzes the Gross-Pitaevskii equation linearized around the degree-one vortex under equivariant symmetry, focusing on the non-selfadjoint matrix operator i\uL. It establishes that the spectrum is the entire real line and derives a Stone-type formula for the evolution by carefully analyzing the resolvent in the complex plane near zero energy, where a zero-energy resonance induces a distinct L^2-norm growth. A complete construction of the distorted Fourier transform at small energies is carried out via a delicate combination of Weyl solutions near r=0 and r=\infty, Lyapunov-Perron fixed points, and a detailed control of the resolvent’s jump. The results yield both sharp L^2-growth bounds for frequency-localized evolution and a framework to read off dispersive behavior through the distorted Fourier representation, complementing concurrent dispersive analyses and enabling a path toward full asymptotic stability questions for the degree-one vortex. The methods hinge on handling strongly singular inverse-square-type potentials, embedding resonances, and implementing a bespoke Stone-type formula to accommodate non-selfadjoint spectral data. These contributions provide a rigorous spectral and scattering-theoretic foundation for the linearized GP dynamics around topological vortices and illuminate how zero-energy phenomena govern long-time evolution and potential stabilization strategies via projection away from L^2-growth modes.
Abstract
We study the evolution of the Gross-Pitaevskii equation linearized around the Ginzburg-Landau vortex of degree one under equivariant symmetry. Among the main results of this work, we determine the spectrum of the linearized operator, uncover a remarkable $L^2$-norm growth phenomenon related to a zero-energy resonance, and provide a complete construction of the distorted Fourier transform at small energies. The latter hinges upon a meticulous analysis of the behavior of the resolvent in the upper and lower half-planes in a small disk around zero-energy.
