Finite and full scale localization for the multi-frequency quasi-periodic CMV matrices
Bei Zhang, Daxiong Piao
TL;DR
This paper develops finite-scale and full-scale localization for multi-frequency quasi-periodic CMV matrices, extending the localization framework known for MF-QP Schrödinger operators to the CMV setting. The authors establish a robust Lyapunov-Exponential structure via large deviation estimates for the monodromy and its entries, derive a CMV-specific Poisson formula, and prove finite-scale localization by combining LDT with the Avalanche Principle and Poisson analysis. They then introduce a semialgebraic-sets approach and a no-double-resonance (NDR) condition to eliminate double resonances, culminating in full-scale localization through scale-bridging arguments, Cartan-type control, and Weierstrass preparation. The results significantly advance spectral localization theory for MF-QP CMV matrices, connecting CMV analysis with the established MF-QP Schrödinger theory and impacting quantum-walk/CMV-related spectral problems.
Abstract
This paper formulates the finite and full-scale localization for multi-frequency quasi-periodic CMV matrices. This can be viewed as the CMV counterpart to the localization results by Goldstein, Schlag, and Voda [arXiv:1610.00380 (math.SP], Invent. Math. 217 (2019)) on multi-frequency quasi-periodic Schrödinger operators.
