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It has only recently been possible to study the superconducting state in the attractive Hubbard Hamiltonian via a direct observation of the formation of a gap in the density of states N(w). Here we determine the effect of random chemical…

Strongly Correlated Electrons · Physics 2009-10-31 Carey Huscroft , Richard T. Scalettar

The density of states of a self-adjoint operator generalizes the eigenvalue distribution of a Hermitian matrix. We prove convergence of the density of states for a tight-binding model with a slowly-varying periodic potential to the density…

Numerical Analysis · Mathematics 2025-12-16 Peter Hofhansel , Alexander B. Watson

Non-Hermitian random matrices with statistical spectral characteristics beyond the standard Ginibre ensembles have recently emerged in the description of dissipative quantum many-body systems as well as in non-ergodic wave transport in…

Mathematical Physics · Physics 2025-11-27 Gernot Akemann , Yan V. Fyodorov , Dmitry V. Savin

We analyze the response of a complex quantum-mechanical system (e. g., a quantum dot) to a time-dependent perturbation. Assuming the dot energy spectrum and the perturbation to be described by the Gaussian Orthogonal Ensemble of random…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 D. M. Basko , M. A. Skvortsov , V. E. Kravtsov

We prove that the local eigenvalue statistics for $d=1$ random band matrices with fixed bandwidth and, for example, Gaussian entries, is given by a Poisson point process and we identify the intensity of the process. The proof relies on an…

Mathematical Physics · Physics 2020-09-01 Benjamin Brodie , Peter D. Hislop

We prove that the the density of states measure (DOSm) for random Schr\"odinger operators on $\mathbb{Z}^d$ is weak-$^*$ H\"older-continuous in the probability measure. The framework we develop is general enough to extend to a wide range of…

Mathematical Physics · Physics 2018-06-13 Peter D. Hislop , Christoph A. Marx

We consider a two dimensional random band matrix ensemble, in the limit of infinite volume and fixed but large band width $W$. For this model we rigorously prove smoothness of the averaged density of states. We also prove that the resulting…

Mathematical Physics · Physics 2017-05-01 Margherita Disertori , Mareike Lager

We study various methods to generate ensembles of random density matrices of a fixed size N, obtained by partial trace of pure states on composite systems. Structured ensembles of random pure states, invariant with respect to local unitary…

Quantum Physics · Physics 2019-02-27 Karol Zyczkowski , Karol A. Penson , Ion Nechita , Benoit Collins

We consider an ensemble of $2\times 2$ normal matrices with complex entries representing operators in the quantum mechanics of 2 - level parity-time reversal (PT) symmetric systems. The randomness of the ensemble is endowed by obtaining…

Mathematical Physics · Physics 2025-01-14 Stalin Abraham , A. Bhagwat , Sudhir Ranjan Jain

Non-hermitian systems have gained a lot of interest in recent years. However, notions of chaos and localization in such systems have not reached the same level of maturity as in the Hermitian systems. Here, we consider non-hermitian…

Disordered Systems and Neural Networks · Physics 2022-10-19 Soumi Ghosh , Sparsh Gupta , Manas Kulkarni

Perhaps surprisingly, recent studies have shown probabilistic model likelihoods have poor specificity for out-of-distribution (OOD) detection and often assign higher likelihoods to OOD data than in-distribution data. To ameliorate this…

This article is intended to provide a pedagogical introduction to the supersymmetry method for performing ensemble-averaging in Gaussian random-matrix theory. The method is illustrated by a detailed calculation of the simplest non-trivial…

Condensed Matter · Physics 2008-02-03 Josef A. Zuk

We study spectral statistics of a Gaussian unitary critical ensemble of almost diagonal Hermitian random matrices with off-diagonal entries $<|H_{ij}|^{2} > \sim b^{2} |i-j|^{-2}$ small compared to diagonal ones $<|H_{ii}|^{2} > \sim 1$.…

Disordered Systems and Neural Networks · Physics 2011-03-25 Vladimir E. Kravtsov , Oleg Yevtushenko , Emilio Cuevas

Models of disorder with a direction (constant imaginary vector-potential) are considered. These non-Hermitian models can appear as a result of computation for models of statistical physics using transfer matrix technique or describe…

Disordered Systems and Neural Networks · Physics 2009-10-30 K. B. Efetov

Linearizing the Heisenberg equations of motion around the ground state of an interacting quantum many-body system, one gets a time-evolution generator in the positive cone of a real symplectic Lie algebra. The presence of disorder in the…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 T. Lueck , H. -J. Sommers , M. R. Zirnbauer

In a differential approach elaborated, we study the evolution of the parameters of Gaussian, mixed, continuous variable density matrices, whose dynamics are given by Hermitian Hamiltonians expressed as quadratic forms of the position and…

Quantum Physics · Physics 2020-05-26 Julio A. López-Saldívar , Margarita A. Man'ko , Vladimir I. Man'ko

Implementing an improved method for analytic continuation and working with imaginary-time correlation functions computed using quantum Monte Carlo simulations, we resolve the single-particle dispersion relation and the density of states…

Strongly Correlated Electrons · Physics 2025-08-08 Gabe Schumm , Shiwei Zhang , Anders W. Sandvik

The density of states (DOS) is a spectral property of materials, which provides fundamental insights on various characteristics of materials. In this paper, we propose a model to predict the DOS by reflecting the nature of DOS: DOS…

Machine Learning · Computer Science 2023-04-11 Namkyeong Lee , Heewoong Noh , Sungwon Kim , Dongmin Hyun , Gyoung S. Na , Chanyoung Park

The spectral density of various ensembles of sparse symmetric random matrices is analyzed using the cavity method. We consider two cases: matrices whose associated graphs are locally tree-like, and sparse covariance matrices. We derive a…

Disordered Systems and Neural Networks · Physics 2009-11-13 Tim Rogers , Koujin Takeda , Isaac Pérez Castillo , Reimer Kühn

We numerically investigate the vibrational spectra of single-component clusters in two-dimensions. Stable configurations of clusters at local energy minima are obtained, and for each the hessian matrix is evaluated and diagonalized to…

Disordered Systems and Neural Networks · Physics 2009-11-13 Gurpreet S. Matharoo