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By means of the technique of integration within an ordered product of operators and Dirac notation, we introduce a new kind of asymmetric integration projection operators in entangled state representations. These asymmetric projection…

Quantum Physics · Physics 2021-05-19 S. Wang , Z. P. Wang , J. D. Zhang

A projection operator is introduced, which exactly transforms the inhomogeneous Nakajima--Zwanzig generalized master equation for the relevant part of a system +bath statistical operator, containing the inhomogeneous irrelevant term…

Quantum Physics · Physics 2025-03-03 Victor F. Los

Starting with the first-order singular Lagrangian describing the dynamical system with 2nd-class constraints, the noncommutative quantum mechanics on a curved space is investigated by the constraint star-product quantization formalism of…

Quantum Physics · Physics 2017-06-29 M. Nakamura

We discuss that there is a crucial contradiction within quantum mechanics. We derive a proposition concerning a quantum expectation value under the assumption of the existence of the directions in a spin-1/2 system. The quantum predictions…

General Physics · Physics 2008-11-28 Koji Nagata , Tadao Nakamura

We discuss some mathematical aspects of the Mori-Zwanzig projection operator formalism. The core of the Mori-Zwanzig formalism is the generalised Langevin equation, which is typically derived from the Dyson-Duhamel identity. We derive the…

Mathematical Physics · Physics 2026-04-23 Christoph Widder , Tanja Schilling

We argue for an operational requirement that all state-dependent measures of disturbance should satisfy. Motivated by this natural criterion, we prove that in any $d$-dimensional Hilbert space and for any pair of non-commuting operators,…

Quantum Physics · Physics 2014-05-13 Kamil Korzekwa , David Jennings , Terry Rudolph

We develop a synthesis of Turing's paradigm of computation and von Neumann's quantum logic to serve as a model for quantum computation with recursion, such that potentially non-terminating computation can take place, as in a quantum Turing…

Quantum Physics · Physics 2009-11-10 A. Edalat

In this chapter, the Hilbert space framework in the mathematical theory of composite materials is introduced for studying the properties of effective operators. The goal is to introduce some of the key concepts and fundamental theorems in…

Mathematical Physics · Physics 2025-12-11 Aaron Welters

In this paper, we investigate the connection between Classical and Quantum Mechanics by dividing Quantum Theory in two parts: - General Quantum Axiomatics (a system is described by a state in a Hilbert space, observables are self-adjoint…

Quantum Physics · Physics 2009-11-07 H. Bergeron

The finite-size scaling spectra of the spin-1/2 XXZ Heisenberg chain with toroidal boundary conditions and an even number of sites provide a projection mechanism yielding the spectra of models with a central charge c<1 including the unitary…

High Energy Physics - Theory · Physics 2015-06-26 Uwe Grimm , Gunter M. Schuetz

We identify an operational principle that singles out Projection-Valued Measures (PVMs) among general Positive Operator-Valued Measures (POVMs), bridging the modern quantum measurement theory and the traditional formulation based on…

Quantum Physics · Physics 2026-05-29 Shun Umekawa , Koki Ono , Hayato Arai

We propose a matrix model for two- and many-valued logic using families of observables in Hilbert space, the eigenvalues give the truth values of logical propositions where the atomic input proposition cases are represented by the…

Quantum Physics · Physics 2016-07-14 Francois Dubois , Zeno Toffano

We perform the covariant operator quantization of the spin-$1$ model in $2+1$ spacetime dimensions to rigorously establish its dualities. For this purpose, the Kugo-Ojima-Nakanishi formalism, based on an indefinite metric Hilbert space in…

High Energy Physics - Theory · Physics 2019-12-06 G. B. de Gracia , B. M. Pimentel , L. Rabanal

An extension of the conditional expectations (those under a given subalgebra of events and not the simple ones under a single event) from the classical to the quantum case is presented. In the classical case, the conditional expectations…

Mathematical Physics · Physics 2010-01-22 Gerd Niestegge

In this work, a new ansatz is introduced to make the calculations of the metric operator in Pseudo-Hermitian field theory simpler. The idea is to assume that the metric operator is not only a functional of the field operators $\phi$ and its…

High Energy Physics - Theory · Physics 2009-11-24 Abouzeid M. Shalaby

A fairly brief and complete presentation of the Zwanzig-Mori projection operator technique is given.

Statistical Mechanics · Physics 2025-11-18 Nail Fatkullin

Motivated by the expectation that relativistic symmetries might acquire quantum features in Quantum Gravity, we take the first steps towards a theory of ''Doubly'' Quantum Mechanics, a modification of Quantum Mechanics in which the…

Quantum Physics · Physics 2025-04-30 Vittorio D'Esposito , Giuseppe Fabiano , Domenico Frattulillo , Flavio Mercati

Most quantum theorists are familiar with different ways of describing the effective quantum dynamics of a system coupled to external degrees of freedom, such as the Born-Markov master equation or the adiabatic elimination. Understanding the…

Quantum Physics · Physics 2024-09-04 C. Gonzalez-Ballestero

The non-commutativity of the position and momentum operators is formulated as an effective potential in classical phase space and expanded as a series of successive many-body terms, with the pair term being dominant. A non-linear partial…

Quantum Physics · Physics 2020-08-11 Phil Attard

We present an extension of Naimark's duality principle which states that complete systems in a Hilbert space are projections of $\omega$-linearly independent systems of elements of an ambient Hilbert space. This result is presented in the…

Functional Analysis · Mathematics 2007-05-23 Wojciech Czaja