On the dispersive estimates for the discrete Schrödinger equation on a honeycomb lattice

Fuente: arXiv
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Main Authors: Hong, Younghun, Tadano, Yukihide, Yang, Changhun
Format: Preprint
Published: 2025
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author Hong, Younghun
Tadano, Yukihide
Yang, Changhun
author_facet Hong, Younghun
Tadano, Yukihide
Yang, Changhun
contents The discrete Schrödinger equation on a two-dimensional honeycomb lattice is a fundamental tight-binding approximation model that describes the propagation of waves on graphene. For free evolution, we first show that the degenerate frequencies of the dispersion relation are completely characterized by three symmetric periodic curves (Theorem 2.1), and that the three curves meet at Dirac points where conical singularities appear (see Figure 2.1). Based on this observation, we prove the $L^1\to L^\infty$ dispersion estimates for the linear flow depending on the frequency localization (Theorem 2.3). Collecting all, we obtain the dispersion estimate with $O(|t|^{-2/3})$ decay as well as Strichartz estimates. As an application, we prove small data scattering for a nonlinear model (Theorem 2.10). The proof of the key dispersion estimates is based on the associated oscillatory integral estimates with degenerate phases and conical singularities at Dirac points. Our proof is direct and uses only elementary methods.
format Preprint
id arxiv_https___arxiv_org_abs_2503_08996
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle On the dispersive estimates for the discrete Schrödinger equation on a honeycomb lattice
Hong, Younghun
Tadano, Yukihide
Yang, Changhun
Analysis of PDEs
37K60, 35Q55, 42B20
The discrete Schrödinger equation on a two-dimensional honeycomb lattice is a fundamental tight-binding approximation model that describes the propagation of waves on graphene. For free evolution, we first show that the degenerate frequencies of the dispersion relation are completely characterized by three symmetric periodic curves (Theorem 2.1), and that the three curves meet at Dirac points where conical singularities appear (see Figure 2.1). Based on this observation, we prove the $L^1\to L^\infty$ dispersion estimates for the linear flow depending on the frequency localization (Theorem 2.3). Collecting all, we obtain the dispersion estimate with $O(|t|^{-2/3})$ decay as well as Strichartz estimates. As an application, we prove small data scattering for a nonlinear model (Theorem 2.10). The proof of the key dispersion estimates is based on the associated oscillatory integral estimates with degenerate phases and conical singularities at Dirac points. Our proof is direct and uses only elementary methods.
title On the dispersive estimates for the discrete Schrödinger equation on a honeycomb lattice
topic Analysis of PDEs
37K60, 35Q55, 42B20
url https://arxiv.org/abs/2503.08996