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Related papers: Spectral Analysis for Non-Hermitian Matrices and D…

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We numerically analyze the spectral statistics of the multiparametric Gaussian ensembles of complex matrices with zero mean and variances with different decay routes away from the diagonals. As the latter mimics different degree of…

Disordered Systems and Neural Networks · Physics 2024-03-05 Mohd. Gayas Ansari , Pragya Shukla

Non-Hermitian models with real eigenenergies are highly desirable for their stability. Yet, most of the currently known ones are constrained by symmetries such as PT-symmetry, which is incompatible with realizing some of the most exotic…

Mesoscale and Nanoscale Physics · Physics 2022-07-13 Boxue Zhang , Qingya Li , Xiao Zhang , Ching Hua Lee

In this paper, we extend the recent analysis of the new large $D$ limit of matrix models to the cases where the action contains arbitrary multi-trace interaction terms as well as to arbitrary correlation functions. We discuss both the cases…

High Energy Physics - Theory · Physics 2018-05-23 Tatsuo Azeyanagi , Frank Ferrari , Paolo Gregori , Laetitia Leduc , Guillaume Valette

Scaled Relative Graphs (SRGs) provide a novel graphical frequency-domain method for the analysis of nonlinear systems. However, we show that the current SRG analysis suffers from a pitfall that limit its applicability in analyzing practical…

Systems and Control · Electrical Eng. & Systems 2025-04-14 Julius P. J. Krebbekx , Roland Tóth , Amritam Das

We apply the recently introduced method of hermitization to study in the large $N$ limit non-hermitean random matrices that are drawn from a large class of circularly symmetric non-Gaussian probability distributions, thus extending the…

Disordered Systems and Neural Networks · Physics 2009-10-30 J. Feinberg , A. Zee

This paper is a detailed account of the recent progress in understanding the statistical properties of complex eigenvalues of random non-Hermitian matrices reported earlier in our two short communications: Physics Letters A v.226, 46 (1997)…

chao-dyn · Physics 2007-05-23 Yan V. Fyodorov , Boris Khoruzhenko , H. -J. Sommers

Using a nonperturbative approach we examine the large frequency asymptotics of the two-point level density correlator in weakly disordered metallic grains. This allows us to study the behavior of the two-level structure factor close to the…

Condensed Matter · Physics 2016-08-31 A. V. Andreev , B. L. Altshuler

We revisit the celebrated Hellmann-Feynman theorem (HFT) in the PT invariant non-Hermitian quantum physics framework. We derive a modified version of HFT by changing the definition of inner product and explicitly show that it holds good for…

Quantum Physics · Physics 2023-08-29 Gaurav Hajong , Ranjan Modak , Bhabani Prasad Mandal

In this paper we consider the concept of preintersection numbers of a graph. These numbers are determined by the spectrum of the adjacency matrix of the graph, and generalize the intersection numbers of a distance-regular graph. By using…

Combinatorics · Mathematics 2016-04-20 A. Abiad , E. R. van Dam , M. A. Fiol

We describe work on solutions of certain non-divergence type and therefore non-variational elliptic and parabolic systems on manifolds. These systems include Hermitian and affine harmonics which should become useful tools for studying…

Differential Geometry · Mathematics 2010-11-16 Jürgen Jost , Fatma Muazzez Şimşir

We consider a discrete, non-Hermitian random matrix model, which can be expressed as a shift of a rank-one perturbation of an anti-symmetric matrix. We show that, asymptotically almost surely, the real parts of the eigenvalues of the…

Probability · Mathematics 2016-11-22 Philippe Sosoe , Uzy Smilansky

We discuss some simple H\"uckel-like matrix representations of non-Hermitian operators with antiunitary symmetries that include generalized $\mathcal{PT}$ (parity transformation followed by time-reversal) symmetry. One of them exhibits…

Quantum Physics · Physics 2024-11-26 Francisco M. Fernández

Green's functions are fundamental quantities that determine the linear responses of physical systems. The recent developments of non-Hermitian systems, therefore, call for Green's function formulas of non-Hermitian bands. This task is…

Mesoscale and Nanoscale Physics · Physics 2021-12-17 Wen-Tan Xue , Ming-Rui Li , Yu-Min Hu , Fei Song , Zhong Wang

We show that similarity (or equivalent) transformations enable one to construct non-Hermitian operators with real spectrum. In this way we can also prove and generalize the results obtained by other authors by means of a gauge-like…

Quantum Physics · Physics 2016-08-08 Francisco M. Fernández

We give a necessary and sufficient condition for the reality of the spectrum of a non-Hermitian Hamiltonian admitting a complete set of biorthonormal eigenvectors.

Mathematical Physics · Physics 2011-05-05 Ali Mostafazadeh

Large families of Hamiltonians that are non-Hermitian in the conventional sense have been found to have all eigenvalues real, a fact attributed to an unbroken PT symmetry. The corresponding quantum theories possess an unconventional scalar…

Quantum Physics · Physics 2009-11-11 Zafar Ahmed , Carl M. Bender , M. V. Berry

Non-Hermitian disordered systems have emerged as a central arena in modern physics, with ramifications spanning condensed matter, quantum, statistical, and high energy contexts. The same principles also underlie phenomena beyond physics,…

Mesoscale and Nanoscale Physics · Physics 2026-03-24 Kohei Kawabata , Shinsei Ryu

We study the spectral statistics of quantum (metric) graphs whose vertices are equipped with preferred orientation vertex conditions. When comparing their spectral statistics to those predicted by suitable random matrix theory ensembles,…

Spectral Theory · Mathematics 2025-08-08 Ram Band , Pavel Exner , Divya Goel , Aviya Strauss

One of the aims of this paper is to solve an open problem of Lovasz about relations between graph spectra and cut-distance. The paper starts with several inequalities between two versions of the cut-norm and the two largest singular values…

Functional Analysis · Mathematics 2009-12-03 Vladimir Nikiforov

Motivated by recent progress on non-Hermitian topological band theories, we study the energy spectrum of a generic two-band non-Hermitian Hamiltonian. We prove rigorously that the complex energy spectrum of such a non-Hermitian Hamiltonian…

Mesoscale and Nanoscale Physics · Physics 2019-05-24 Jonatan Melkær Midtgaard , Zhigang Wu , Yu Chen