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In the quantum mechanical Hilbert space formalism, the probabilistic interpretation is a later ad-hoc add-on, more or less enforced by the experimental evidence, but not motivated by the mathematical model itself. A model involving a clear…

Mathematical Physics · Physics 2010-12-21 Gerd Niestegge

A recent result about measurability of a quantum state of a single quantum system is generalized to the case of a single pre- and post-selected quantum system described by a two-state vector. The protection required for such measurement is…

Quantum Physics · Physics 2007-05-23 Y. Aharonov , L. Vaidman

We propose a new model for a measurement of a characteristic of a microscopic quantum state by a large system that selects stochastically the different eigenstates with appropriate quantum weights. Unlike previous works which formulate a…

Quantum Physics · Physics 2009-01-24 Fariel Shafee

Predicting observables in equilibrium states is a central yet notoriously hard question in quantum many-body systems. In the physically relevant thermodynamic limit, certain mathematical formulations of this task have even been shown to…

Quantum Physics · Physics 2025-08-15 Hamza Fawzi , Omar Fawzi , Samuel O. Scalet

The Hamiltonian of a quantum system governs the dynamics of the system via the Schrodinger equation. In this paper, the Hamiltonian is reconstructed in the Pauli basis using measurables on random states forming a time series dataset. The…

Quantum Physics · Physics 2023-05-10 Rishabh Gupta , Raja Selvarajan , Manas Sajjan , Raphael D. Levine , Sabre Kais

A non-hermitian deformation of the one-dimensional transverse Ising model is shown to have the property of quasi-hermiticity. The transverse Ising chain is obtained from the starting non-hermitian Hamiltonian through a similarity…

Statistical Mechanics · Physics 2009-11-09 Tetsuo Deguchi , Pijush K. Ghosh

In the Schroedinger equation, time plays a special role as an external parameter. We show that in an enlarged system where the time variable denotes an additional degree of freedom, solutions of the Schroedinger equation give rise to…

Mathematical Physics · Physics 2014-11-20 Romeo Brunetti , Klaus Fredenhagen , Marc Hoge

The tomographic description of a quantum state is formulated in an abstract infinite dimensional Hilbert space framework, the space of the Hilbert-Schmidt linear operators, with trace formula as scalar product. Resolutions of the unity,…

Quantum Physics · Physics 2007-05-23 V. I. Man'ko , G. Marmo , A. Simoni , F. Ventriglia

By using a real matrix translation, we propose a coupled eigenvalue problem for octonionic operators. In view of possible applications in quantum mechanics, we also discuss the hermiticity of such operators. Previous difficulties in…

Mathematical Physics · Physics 2015-06-11 Stefano De Leo , Gisele Ducati

We represent low dimensional quantum mechanical Hamiltonians by moderately sized finite matrices that reproduce the lowest O(10) boundstate energies and wave functions to machine precision. The method extends also to Hamiltonians that are…

Quantum Physics · Physics 2015-06-03 Johann Foerster , Alejandro Saenz , Ulli Wolff

Recently, a geometric embedding of the classical space and classical phase space of an n-particle system into the space of states of the system was constructed and shown to be physically meaningful. Namely, the Newtonian dynamics of the…

Quantum Physics · Physics 2022-04-13 Alexey A. Kryukov

States of a quantum mechanical system are represented by rays in a complex Hilbert space. The space of rays has, naturally, the structure of a K\"ahler manifold. This leads to a geometrical formulation of the postulates of quantum mechanics…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Abhay Ashtekar , Troy A. Schilling

An early approach to include pointers representing measurement devices into quantum mechanics was given by von Neumann. Based on this idea, we model such pointers by qubits and couple them to a free particle, in analogy to a classical…

Quantum Physics · Physics 2021-10-22 Bernd Konrad , Fabio Di Pumpo , Matthias Freyberger

We give an explicit characterization of the most general quasi-Hermitian operator H, the associated metric operators \eta_+, and \eta_+-pseudo-Hermitian operators acting in two-dimensional complex Euclidean space C^2. These operators…

Quantum Physics · Physics 2007-05-23 Ali Mostafazadeh , Seher Ozcelik

Sturmian bound states emerging at a fixed energy and numbered by a complete set of real eigencouplings are considered. For Sturm-Schroedinger equations which are manifestly non-Hermitian we outline the way along which the correct…

Quantum Physics · Physics 2008-04-25 Miloslav Znojil

The quantum measurement problem considered for the model of measuring system (MS) consist of measured state S (particle), detector D and information processing device (observer) $O$ interacting with S,D. For 'external' observer $O'$ MS…

Quantum Physics · Physics 2007-05-23 Mayburov. S

The full spectrum and eigenfunctions of the quantum version of a nonlinear oscillator defined on an N-dimensional space with nonconstant curvature are rigorously found. Since the underlying curved space generates a position-dependent…

We generalize entanglement detection with covariance matrices for an arbitrary set of observables. A generalized uncertainty relation is constructed using the covariance and commutation matrices, then a criterion is established by…

Quantum Physics · Physics 2018-06-12 Vinay Tripathi , Chandrashekar Radhakrishnan , Tim Byrnes

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

Schr\"odinger's equation serves as a fundamental component in characterizing quantum systems, wherein both quantum state tomography and Hamiltonian learning are instrumental in comprehending and interpreting quantum systems. While numerous…

Quantum Physics · Physics 2024-01-25 Zheng An , Jiahui Wu , Muchun Yang , D. L. Zhou , Bei Zeng
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