Wegner estimates for sign-changing single site potentials

Wegner Estimate for Indefinite Anderson Potentials: Some Recent Results and Applications

We review recent and give some new results on the spectral properties of Schroedinger operators with a random potential of alloy type. Our point of interest is the so called Wegner estimate in the case where the single site potentials change sign. The indefinitness of the single site potential poses certain difficulties for the proof of the Wegner estimate which are still not fully understood. The Wegner estimate is a key ingredient in an existence proof of pure point spectrum of the considered random Schroedinger operators. Under certain assumptions on the considered models additionally the e…

Wegner estimate and the density of states of some indefinite alloy type Schroedinger Operators

We study Schroedinger operators with a random potential of alloy type. The single site potentials are allowed to change sign. For a certain class of them we prove a Wegner estimate. This is a key ingredient in an existence proof of pure point spectrum of the considered random Schroedinger operators. Our estimate is valid for all bounded energy intervals and all space dimensions and implies the existence of the density of states.

A linear Wegner estimate for alloy type Schroedinger operators on metric graphs

We study spectra of alloy-type random Schrödinger operators on metric graphs. For finite edge subsets of general graphs we prove a Wegner estimate which is linear in the volume (i.e. the number of edges) and the length of the considered energy interval. The single site potential of the alloy-type model needs to have fixed sign, but the considered metric graph does not need to have a periodic structure. The second result we obtain is an exhaustion construction of the integrated density of states for ergodic random Schrödinger operators on metric graphs with a $\ZZ^ν$-structure. For certain mode…

Optimal Wegner estimates for random Schroedinger operators on metric graphs

We consider Schroedinger operators with a random potential of alloy type on infinite metric graphs which obey certain uniformity conditions. For single site potentials of fixed sign we prove that the random Schroedinger operator restricted to a finite volume subgraph obeys a Wegner estimate which is linear in the volume and reproduces the modulus of continuity of the single site distribution. This improves and unifies earlier results for alloy type models on metric graphs. We discuss applications of Wegner estimates to bounds of the modulus of continuity of the integrated density of states of …

Localization for random operators with non-monotone potentials with exponentially decaying correlations

I consider random Schrödinger operators with exponentially decaying single site potential, which is allowed to change sign. For this model, I prove Anderson localization both in the sense of exponentially decaying eigenfunctions and dynamical localization. Furthermore, the results imply a Wegner-type estimate strong enough to use in classical forms of multi-scale analysis.

一种用于指数大偏差估计的“提升”方法及其在特定非平稳一维晶格Anderson模型中的应用

A "lifting" method for exponential large deviation estimates and an application to certain non-stationary 1D lattice Anderson models

本文提出一种“提升”方法，将平稳模型的指数大偏差估计推广到非平稳模型，并据此推导一维晶格上特定非平稳势的Anderson局域化。