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Related papers: Almost localization and almost reducibility

200 papers

We establish a quantitative version of strong almost reducibility result for $\mathrm{sl}(2,\mathbb{R})$ quasi-periodic cocycle close to a constant in Gevrey class. We prove that, for the quasi-periodic Schr\"odinger operators with small…

Dynamical Systems · Mathematics 2023-01-12 Xianzhe Li

We establish both Anderson localization and H\"older continuity of the integrated density of states for quasiperiodic Schr\"odinger operators on $\mathbb{Z}^d$ with any non-constant analytic potential and any Diophantine frequency in the…

Mathematical Physics · Physics 2026-04-14 Hongyi Cao , Yunfeng Shi , Zhifei Zhang

Avila's Almost Reducibility Conjecture (ARC) is a powerful statement linking purely analytic and dynamical properties of analytic one frequency $SL(2,\mathbb{C})$ cocycles. It is also a fundamental tool in the study of spectral theory of…

Dynamical Systems · Mathematics 2023-09-12 Lingrui Ge

The sequence of ground state energy density at finite size, e_{L}, provides much more information than usually believed. Having at disposal e_{L} for short lattice sizes, we show how to re-construct an approximate quasi-particle dispersion…

Quantum Physics · Physics 2015-03-17 Lorenzo Campos Venuti

The arithmetic version of Anderson localization (AL), i.e., AL with explicit arithmetic description on both the localization frequency and the localization phase, was first given by Jitomirskaya \cite{J} for the almost Mathieu operators…

Dynamical Systems · Mathematics 2020-04-01 Lingrui Ge , Jiangong You

We prove that infinitely differentiable almost reducible quasi-periodic cocycles, under a Diophantine condition on the frequency vector, are almost reducible to a sequence of real constant cocycles with a sequence of real conjugations, up…

Dynamical Systems · Mathematics 2025-08-26 Maxime Chatal , Claire Chavaudret , L. Hakan Eliasson

We give a simple argument that if a quasiperiodic multi-frequency Schr\"odinger cocycle is reducible to a constant rotation for almost all energies with respect to the density of states measure, then the spectrum of the dual operator is…

Spectral Theory · Mathematics 2015-05-28 Svetlana Jitomirskaya , Ilya Kachkovskiy

We study the reducibility of a Linear Schr\"odinger equation subject to a small unbounded almost-periodic perturbation which is analytic in time and space. Under appropriate assumptions on the smallness, analiticity and on the frequency of…

Analysis of PDEs · Mathematics 2019-10-29 Riccardo Montalto , Michela Procesi

In this paper, we prove that any analytic quasi-periodic cocycle close to constant is the Poincar\'{e} map of an analytic quasi-periodic linear system close to constant. With this local embedding theorem, we get fruitful new results. We…

Dynamical Systems · Mathematics 2015-06-04 Jiangong You , Qi Zhou

We prove absolute continuity of the integrated density of states for frequency-independent analytic perturbations of the non-critical almost Mathieu operator under arithmetic conditions on frequency.

Spectral Theory · Mathematics 2023-05-10 Lingrui Ge , Svetlana Jitomirskaya , Xin Zhao

We apply recently developed methods for the construction of quasi-periodic transfer matrices to the Dry Ten Martini problem for the critical almost-Mathieu Operator, also known as the Aubry-Andre-Harper (AAH) model.

Mathematical Physics · Physics 2021-12-14 Dan S. Borgnia , Robert-Jan Slager

We construct a tight-binding model that hosts both a quasi-periodic nature and marcoscopically-dengenerate zero-energy modes. The model can be regarded as a counterpart of the Aubry-Andr\'{e}-Harper (AAH) model, which is a paradigmatic…

Mesoscale and Nanoscale Physics · Physics 2025-06-11 Tomonari Mizoguchi , Yasuhiro Hatsugai

It is well-established that the spectral measure for one-frequency Schr\"odinger operators with Diophantine frequencies exhibits optimal $1/2$-H\"older continuity within the absolutely continuous spectrum. This study extends these findings…

Mathematical Physics · Physics 2024-07-15 Xianzhe Li , Jiangong You , Qi Zhou

We study discrete Schroedinger operators with analytic potentials. In particular, we are interested in the connection between the absolutely continuous spectrum in the almost periodic case and the spectra in the periodic case. We prove a…

Spectral Theory · Mathematics 2011-04-19 Mira Shamis

For a class of discrete quasi-periodic Schroedinger operators defined by covariant re- presentations of the rotation algebra, a lower bound on phase-averaged transport in terms of the multifractal dimensions of the density of states is…

Mathematical Physics · Physics 2009-11-10 Jean Bellissard , Italo Guarneri , Hermann Schulz-Baldes

A new non-Hermitian E2-quasi-exactly solvable model is constructed containing two previously known models of this type as limits in one of its three parameters. We identify the optimal finite approximation to the double scaling limit to the…

Quantum Physics · Physics 2016-06-10 Andreas Fring

We consider separable 2D discrete Schr\"odinger operators generated by 1D almost Mathieu operators. For fixed Diophantine frequencies we prove that for sufficiently small couplings the spectrum must be an interval. This complements a result…

Spectral Theory · Mathematics 2021-11-03 Alberto Takase

We introduce a two-dimensional generalisation of the quasiperiodic Aubry-Andr\'e model. Even though this model exhibits the same duality relation as the one-dimensional version, its localisation properties are found to be substantially more…

Disordered Systems and Neural Networks · Physics 2020-02-20 Attila Szabó , Ulrich Schneider

The nearest-neighbor Aubry-Andr\'e quasiperiodic localization model is generalized to include power-law translation-invariant hoppings $T_l\propto t/l^a$ or power-law Fourier coefficients $W_m \propto w/m^b$ in the quasi-periodic potential.…

Disordered Systems and Neural Networks · Physics 2019-06-04 Cecile Monthus

We prove a reducibility result for sl(2,R) quasi-periodic cocycles close to a constant elliptic matrix in ultra-differentiable classes, under an adapted arithmetic condition which extends the Brjuno-R{\"u}ssmann condition in the analytic…

Dynamical Systems · Mathematics 2019-12-16 Abed Bounemoura , Claire Chavaudret , Shuqing Liang