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Unitarity is a cornerstone of quantum theory, ensuring the conservation of probability and information. Although non-Hermitian Hamiltonians are typically associated with open or dissipative systems, pseudo-Hermitian quantum mechanics shows…

High Energy Physics - Theory · Physics 2025-11-03 Ruifeng Leng , Cheng-Yang Lee , Siyi Zhou

We show that constraints imposed by strong Hilbert space fragmentation (HSF) along with the presence of certain global symmetries can ensure the reality of eigenspectra of non-Hermitian quantum systems; such a reality cannot be guaranteed…

Strongly Correlated Electrons · Physics 2024-07-16 Somsubhra Ghosh , K. Sengupta , Indranil Paul

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

Utilizing scattering theory, we quantify the consequences of physical constraints that limit the visibility of non-Hermitian effects in passive devices. The constraints arise from the fundamental requirement that the system obeys causality,…

Optics · Physics 2023-12-15 Henning Schomerus

The observation that the existance of the amazing reality and discreteness of the spectrum need not be attributed to the Hermiticity of the Hamiltonian is reemphasized in the context of the non-Hermitian Dirac and Klein-Gordon Hamiltonians.…

Mathematical Physics · Physics 2009-11-10 Omar Mustafa

We compare updated predictions for the elastic scattering of supersymmetric neutralino dark matter with the improved experimental upper limit recently published by CDMS II. We take into account the possibility that the \pi-nucleon \Sigma…

High Energy Physics - Phenomenology · Physics 2010-04-06 John Ellis , Keith A. Olive , Yudi Santoso , Vassilis C. Spanos

We discuss non-Hermitian field theories where the spectrum of the Hamiltonian involves only real energies. We make three observations. (i) The theories obtained from supersymmetric theories by nonanticommutative deformations belong in many…

High Energy Physics - Theory · Physics 2008-11-26 A. V. Smilga

Recently, it was established that there exists a direct relation between the non-Hermitian skin effects, -strong dependence of spectra on boundary conditions for non-Hermitian Hamiltonians-, and boundary zero modes for Hermitian topological…

Mesoscale and Nanoscale Physics · Physics 2020-07-10 Nobuyuki Okuma , Masatoshi Sato

The most general combination of couplings of fermions with external potentials in 1+1 dimensions, must include vector, scalar and pseudoscalar potentials. We consider such a mixing of potentials in a PT-symmetric time-independent Dirac…

Quantum Physics · Physics 2015-05-13 V. G. C. S. dos Santos , A. de Souza Dutra , M. B. Hott

Hitherto, it is well known that complex PT-symmetric Scarf II has real discrete spectrum in the parametric domain of unbroken PT-symmetry. We reveal new interesting complex, non-PT-symmetric parametric domains of this versatile potential,…

Quantum Physics · Physics 2015-01-21 Zafar Ahmed , Joseph Amal Nathan

Eigenspectra of a spinless quantum particle trapped inside a rigid, rectangular, two-dimensional (2D) box subject to diverse inner potential distributions are investigated under hermitian, as well as non-hermitian antiunitary $\mathcal{PT}$…

Quantum Physics · Physics 2021-10-13 Shailesh Kulkarni , Rajeev K. Pathak

The study of a particle with position-dependent effective mass (pdem), within a double heterojunction is extended into the complex domain --- when the region within the heterojunctions is described by a non Hermitian ${\cal{PT}}$ symmetric…

Quantum Physics · Physics 2015-06-04 Anjana Sinha

Unitarity imposes coupled constraints on elastic and inelastic amplitudes. Satisfying them requires resummation of the self-energy contributions from both elastic and inelastic channels. Inelastic channels generate anti-Hermitian…

High Energy Physics - Phenomenology · Physics 2026-04-08 Marcos M. Flores , Kalliopi Petraki

A curious feature of complex scattering potentials v(x) is the appearance of spectral singularities. We offer a quantitative description of spectral singularities that identifies them with an obstruction to the existence of a complete…

Mathematical Physics · Physics 2010-06-03 Ali Mostafazadeh , Hossein Mehri-Dehnavi

A fundamental tenet of quantum mechanics is that the energy spectrum of a quantum system shall remain stable against infinitesimally weak and spatially confined perturbations. In this article, we demonstrate that this principle of spectral…

Mesoscale and Nanoscale Physics · Physics 2024-09-23 Chang Shu , Kai Zhang , Kai Sun

Phenomenological issues of no-scale structure of K\"{a}hler potential are re-examined, which arises in various approaches to supersymmetry breaking. When no-scale boundary conditions are given at the Grand Unified scale and universal…

High Energy Physics - Phenomenology · Physics 2011-01-27 Shinji Komine , Masahiro Yamaguchi

The energy spectra of two different quantum systems are paired through supersymmetric algorithms. One of the systems is Hermitian and the other is characterized by a complex-valued potential, both of them with only real eigenvalues in their…

Quantum Physics · Physics 2020-11-04 Kevin Zelaya , Sara Cruz y Cruz , Oscar Rosas-Ortiz

Symplectic ensemble of disordered non-Hermitian Hamiltonians is studied. Starting from a model with an imaginary magnetic field, we derive a proper supermatrix $\sigma $-model. The zero-dimensional version of this model corresponds to a…

Disordered Systems and Neural Networks · Physics 2009-10-31 A. V. Kolesnikov , K. B. Efetov

There is a common belief in the condensed matter community that bulk quantities become insensitive to the boundary condition in the infinite-volume limit. Here we reconsider this statement in terms of recent arguments of non-Hermitian skin…

Mesoscale and Nanoscale Physics · Physics 2021-05-05 Nobuyuki Okuma , Masatoshi Sato

A complexified von Roos Hamiltonian is considered and a Hermitian first-order intertwining differential operator is used to obtain the related position dependent mass $\eta$-weak-pseudo-Hermitian Hamiltonians. Using a Liouvillean-type…

Quantum Physics · Physics 2009-11-13 Omar Mustafa , S. Habib Mazharimousavi