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Related papers: Complex Extension of Quantum Mechanics

200 papers

Examples are given of non-Hermitian Hamiltonian operators which have a real spectrum. Some of the investigated operators are expressed in terms of the generators of the Weil-Heisenberg algebra. It is argued that the existence of an…

Quantum Physics · Physics 2009-09-29 João da Providência , Natália Bebiano , João Pinheiro da Providência

A non-Hermitian Hamiltonian has a real positive spectrum and exhibits unitary time evolution if the Hamiltonian possesses an unbroken PT (space-time reflection) symmetry. The proof of unitarity requires the construction of a linear operator…

High Energy Physics - Theory · Physics 2009-11-10 Carl M. Bender , Sebastian F. Brandt , Jun-Hua Chen , Qinghai Wang

In ${\cal PT}-$symmetric quantum mechanics one of the most characteristic mathematical features of the formalism is the explicit Hamiltonian-dependence of the physical Hilbert space of states ${\cal H}={\cal H}(H)$. Some of the most…

Quantum Physics · Physics 2018-03-20 Miloslav Znojil

This paper builds on our earlier proposal for construction of a positive inner product for pseudo-Hermitian Hamiltonians and we give several examples to clarify our method. We show through the example of the harmonic oscillator how our…

Quantum Physics · Physics 2011-04-07 Ashok Das , L. Greenwood

Since the realization of quantum systems described by non-Hermitian Hamiltonians with parity-time (PT) symmetry, interest in non-Hermitian, quantum many-body models has steadily grown. Most studies to-date map to traditional quantum spin…

Quantum Physics · Physics 2023-12-07 Jacob Muldoon , Yogesh N. Joglekar

A causal, non-Hermitian, renormalizable, local, unitary and Lorentz convariant formulation of Quantum Theory (QT) (= Quantum Mechanics (QM) and Quantum Field Theory (QFT)) is developed which is free of formalistic problems we face in the…

High Energy Physics - Phenomenology · Physics 2011-07-19 F. Kleefeld

We construct the most general form of our previously proposed nonlinear extension of quantum mechanics that possesses three basic properties. Unlike the simpler model, the new version is not completely integrable, but it has an underlying…

Quantum Physics · Physics 2025-11-05 Alan Chodos , Fred Cooper

The complex-valued quantum mechanics considers quantum motion on the complex plane instead of on the real axis, and studies the variations of a particle complex position, momentum and energy along a complex trajectory. On the basis of…

Quantum Physics · Physics 2021-03-23 C. D. Yang , S. Y. Han

In a recent paper it was shown that if a Hamiltonian H has an unbroken PT symmetry, then it also possesses a hidden symmetry represented by the linear operator C. The operator C commutes with both H and PT. The inner product with respect to…

Quantum Physics · Physics 2009-11-07 Carl M. Bender , Peter N. Meisinger , Qinghai Wang

Quasi-Hermitian quantum systems, including $\mathcal{PT}$-symmetric ones, can be mapped to equivalent Hermitian systems via a similarity transformation that redefines the inner product with a positive-definite metric operator. Although an…

Quantum Physics · Physics 2026-05-12 Ming-Zhang Wang , Xu-Yang Hou , Hao Guo

A non-Hermitian operator with a real spectrum and a complete set of eigenvectors may serve as the Hamiltonian operator for a unitary quantum system provided that one makes an appropriate choice for the defining inner product of the physical…

Quantum Physics · Physics 2009-11-13 Ali Mostafazadeh

Universal properties of many-body systems in conformal quantum mechanics in arbitrary dimensions are presented. Specially, a general structure of discrete energy spectra and eigenstates is found. Finally, a simple construction of a…

High Energy Physics - Theory · Physics 2010-11-05 S. Meljanac , A. Samsarov

Quantum Mechanics is a good example of a successful theory. Most of atomic phenomena are described well by quantum mechanics and cases such as Lamb Shift that are not described by quantum mechanics, are described by quantum electrodynamics.…

Quantum Physics · Physics 2013-11-27 Mahdi Atiq , Mozafar Karamian , Mehdi Golshani

For a subclass of a general $\mathcal{PT}-$symmetric Hamiltonian obeying anti-commutation relation with its conjugate, a Hermitian basis is found that spans the bi-orthonormal energy eigenvectors. Using the modified projectors constructed…

Quantum Physics · Physics 2025-12-04 Baibhab Bose , Devvrat Tiwari , Subhashish Banerjee

In this work we present a general formalism to treat non-Hermitian and noncommutative Hamiltonians. This is done employing the phase-space formalism of quantum mechanics, which allows to write a set of robust maps connecting the Hamitonians…

Quantum Physics · Physics 2019-08-15 Jonas F. G. Santos , Fabricio. S. Luiz , Oscar. S. Duarte , Miled. H. Y. Moussa

The operational approach to time is a cornerstone of relativistic theories, as evidenced by the notion of proper time. In standard quantum mechanics, however, time is an external parameter. Recently, many attempts have been made to extend…

Quantum Physics · Physics 2022-11-24 Ismael L. Paiva , Amit Te'eni , Bar Y. Peled , Eliahu Cohen , Yakir Aharonov

In arXiv:0709.0483 Gunther and Samsonov outline a ``generalization'' of quantum mechanics that involves simultaneous consideration of Hermitian and non-Hermitian operators and promises to be ``capable to produce effects beyond those of…

Quantum Physics · Physics 2007-09-13 Ali Mostafazadeh

Starting with the modified Dirac equations for free massive particles with the $\gamma_5$-extension of the physical mass $m\rightarrow m_1 + \gamma_5 m_2$, we consider equations of relativistic quantum mechanics in the presence of an…

High Energy Physics - Theory · Physics 2014-04-03 V. N. Rodionov

The properties which give quantum mechanics its unique character - unitarity, complementarity, non-commutativity, uncertainty, nonlocality - derive from the algebraic structure of Hermitian operators acting on the wavefunction in complex…

Quantum Physics · Physics 2022-09-14 Tim Palmer

The Hermiticity axiom of quantum mechanics guarantees that the energy spectrum is real and the time evolution is unitary (probability-preserving). Nevertheless, non-Hermitian but $\mathcal{PT}$-symmetric Hamiltonians may also have real…

Quantum Physics · Physics 2018-06-06 Fernando Quijandría , Uta Naether , Sahin K. Özdemir , Franco Nori , David Zueco
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