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Related papers: Sequential Products of Quantum Measurements

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We consider some basic problems associated with quantum mechanics of systems having a time-dependent Hilbert space. We provide a consistent treatment of these systems and address the possibility of describing them in terms of a…

Quantum Physics · Physics 2024-09-24 Ali Mostafazadeh

We consider a general symplectic transformation (also known as linear canonical transformation) of quantum-mechanical observables in a quantized version of a finite-dimensional system with configuration space isomorphic to $ \mathbb{R}^{q}…

Quantum Physics · Physics 2021-03-17 Jakub Káninský

A time-dependent product is introduced between the observables of a dissipative quantum system, that accounts for the effects of dissipation on observables and commutators. In the $t \to \infty$ limit this yields a contracted algebra. The…

Quantum Physics · Physics 2012-05-07 Dariusz Chruściński , Paolo Facchi , Giuseppe Marmo , Saverio Pascazio

The interplay between the algebraic structure (operator algebras) for the quantum observables and the convex structure of the state space has been explored for a long time and most advanced results are due to Alfsen and Shultz. Here we…

Quantum Physics · Physics 2024-11-28 Gerd Niestegge

We begin by defining mutually unbiased (MU) observables on a finite dimensional Hilbert space. We also consider the more general concept of parts of MU observables. The relationships between MU observables, value-complementary observables…

Quantum Physics · Physics 2021-10-08 Stan Gudder

It is proposed the scheme of quantum mechanics, in which a Hilbert space and the linear operators are not primary elements of the theory. Instead of it certain variant of the algebraic approach is considered. The elements of noncommutative…

Quantum Physics · Physics 2007-05-23 D. A. Slavnov

Some concepts, such as non-compactness measure and condensing operators, defined on metric spaces are extended to uniform spaces. Such extensions allow us to locate, in the context of uniform spaces, some classical results existing in…

General Topology · Mathematics 2015-11-25 Raúl Fierro

Positive operator measures (with values in the space of bounded operators on a Hilbert space) and their generalizations, mainly positive sesquilinear form measures, are considered with the aim of providing a framework for their generalized…

Functional Analysis · Mathematics 2015-06-26 Tuomas Hytönen , Juha-Pekka Pellonpää , Kari Ylinen

Motivated by the recent developments of pseudo-Hermitian quantum mechanics, we analyze the structure generated by unbounded metric operators in a Hilbert space. To that effect, we consider the notions of similarity and quasi-similarity…

Mathematical Physics · Physics 2016-10-24 Jean-Pierre Antoine , Camillo Trapani

This note aims to investigate the tensor product of two given Hilbert quasi *-algebras and its properties. The construction proposed in this note turns out to be again a Hilbert quasi *-algebra, thus interesting representability properties…

Functional Analysis · Mathematics 2020-02-20 Maria Stella Adamo

We show that any decoherence functional $D$ can be represented by a spanning vector-valued measure on a complex Hilbert space. Moreover, this representation is unique up to an isomorphism when the system is finite. We consider the natural…

Quantum Physics · Physics 2022-09-01 Stan Gudder

The purpose of this paper is to show that the mathematics of quantum mechanics (QM) is the mathematics of set partitions (which specify indefiniteness and definiteness) linearized to vector spaces, particularly in Hilbert spaces. That is,…

Quantum Physics · Physics 2022-09-21 David Ellerman

The questions of describing observables and observation in quantum gravity appear to be centrally important to its physics. A relational approach holds significant promise, and a classification of different types of relational observables…

High Energy Physics - Theory · Physics 2025-06-13 Steven B. Giddings

We study the concept of frame in tensor product of n-Hilbert spaces as tensor product of n-Hilbert spaces is again a n-Hilbert space. We generalize some of the known results about bases to frames in this new Hilbert space. A relationship…

Functional Analysis · Mathematics 2024-03-07 Prasenjit Ghosh , Tapas Kumar Samanta

For any resource theory it is essential to identify tasks for which resource objects offer advantage over free objects. We show that this identification can always be accomplished for resource theories of quantum measurements in which free…

Quantum Physics · Physics 2019-05-01 Michał Oszmaniec , Tanmoy Biswas

This paper is a detailed study of finite-dimensional modules defined on bicomplex numbers. A number of results are proved on bicomplex square matrices, linear operators, orthogonal bases, self-adjoint operators and Hilbert spaces, including…

Functional Analysis · Mathematics 2011-08-10 Raphael Gervais Lavoie , Louis Marchildon , Dominic Rochon

The effects of any quantum measurement can be described by a collection of measurement operators {M_m} acting on the quantum state of the measured system. However, the Hilbert space formalism tends to obscure the relationship between the…

Quantum Physics · Physics 2009-11-07 Holger F. Hofmann

The situation of two independent observers conducting measurements on a joint quantum system is usually modelled using a Hilbert space of tensor product form, each factor associated to one observer. Correspondingly, the operators describing…

Mathematical Physics · Physics 2009-06-25 V. B. Scholz , R. F. Werner

It is often inevitable to introduce an indefinite-metric space in quantum field theory. There is a problem to determine the metric structure of a given representation space of field operators. We show the systematic method to determine such…

Operator Algebras · Mathematics 2007-05-23 Katsunori Kawamura

We consider iterated function systems (finite or countable), together with linear and continuous operators on Hilbert spaces, which enable us to construct Markov-type operators. Under suitable conditions, these Markov-type operators have…

Classical Analysis and ODEs · Mathematics 2017-01-30 Ion Chiţescu , Loredana Ioana , Radu Miculescu , Lucian Niţă