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Related papers: Double Dilation $\neq$ Double Mixing (extended abs…

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We consider the task of filtering a dynamic parameter evolving as a diffusion process, given data collected at discrete times from a likelihood which is conjugate to the marginal law of the diffusion, when a generic dual process on a…

Probability · Mathematics 2023-11-29 Guillaume Kon Kam King , Andrea Pandolfi , Marco Piretto , Matteo Ruggiero

Usually models for quantum computations deal with unitary gates on pure states. In this paper we generalize the usual model. We consider a model of quantum computations in which the state is an operator of density matrix and the gates are…

Quantum Physics · Physics 2007-05-23 Vasily E. Tarasov

We develop a duality theory for unbounded Hermitian operators with dense domain in Hilbert space. As is known, the obstruction for a Hermitian operator to be selfadjoint or to have selfadjoint extensions is measured by a pair of deficiency…

Mathematical Physics · Physics 2009-04-13 Palle E. T. Jorgensen

In this work, we use the recently introduced double-dilation construction by Zwart and Coecke to construct a new categorical probabilistic theory of density hypercubes. By considering multi-slit experiments, we show that the theory displays…

Quantum Physics · Physics 2020-04-30 Stefano Gogioso , Carlo Maria Scandolo

This paper presents a general method for producing randomly perturbed density operators subject to different sets of constraints. The perturbed density operators are a specified "distance" away from the state described by the original…

Quantum Physics · Physics 2024-06-10 J. A. Montanez-Barrera , R. T. Holladay , G. P. Beretta , Michael R. von Spakovsky

We consider the relation between three different approaches to defining quantum states across several times and locations: the pseudo-density matrix (PDM), the process matrix, and the multiple-time state approaches. Previous studies have…

Quantum Physics · Physics 2024-03-14 Xiangjing Liu , Zhian Jia , Yixian Qiu , Fei Li , Oscar Dahlsten

The Wigner function for one and two-mode quantum systems is explicitely expressed in terms of the marginal distribution for the generic linearly transformed quadratures. Then, also the density operator of those systems is written in terms…

Quantum Physics · Physics 2009-10-30 G. M. D'Ariano , S. Mancini , V. I. Man'ko , P. Tombesi

Sz.-Nagy and Foias proved that each $C_{\cdot0}$-contraction has a dilation to a Hardy shift and thus established an elegant analytic functional model for contractions of class $C_{\cdot0}$. This has motivated lots of further works on model…

Functional Analysis · Mathematics 2020-04-21 Hui Dan , Kunyu Guo

The quantum de Finetti theorem says that, given a symmetric state, the state obtained by tracing out some of its subsystems approximates a convex sum of power states. The more subsystems are traced out, the better this approximation…

Quantum Physics · Physics 2007-05-23 Graeme Mitchison

The Douglas' majorization and factorization theorem characterizes the inclusion of operator ranges in Hilbert spaces. Notably, it reinforces the well-established connections between the inclusion of kernels of operators in Hilbert spaces…

Functional Analysis · Mathematics 2024-11-15 Pierre Lissy

We develop a systematic method of obtaining duality symmetric actions in different dimensions. This technique is applied for the quantum mechanical harmonic oscillator, the scalar field theory in two dimensions and the Maxwell theory in…

High Energy Physics - Theory · Physics 2007-05-23 R. Banerjee , C. Wotzasek

The paper presents numerical simulations performed on dielectric properties of two-dimensional binary composites on eleven regular space filling tessellations. First, significant contributions of different parameters, which play an…

Materials Science · Physics 2007-05-23 Enis Tuncer

Many numerical methods for multiscale differential equations require a scale separation between the larger and the smaller scales to achieve accuracy and computational efficiency. In the area of multiscale dynamical systems, so-called,…

Numerical Analysis · Mathematics 2025-07-01 Ziheng Chen , Björn Engquist

Recent instances of successful application of quantum information techniques to particle physics problems invite for an analysis of the mathematical details behind such connection. In this paper, we identify the Choi-Jamiolkowski…

High Energy Physics - Phenomenology · Physics 2023-12-06 Clelia Altomonte , Alan J. Barr

Predictions for measurement outcomes in physical theories are usually computed by combining two distinct notions: a state, describing the physical system, and an observable, describing the measurement which is performed. In quantum theory,…

Quantum Physics · Physics 2012-03-28 Markus P. Mueller , Cozmin Ududec

We show that the relation between the Schr\"odinger equation and diffusion processes has an algebraic nature and can be revealed via the structure of "duplex numbers." This helps one to clarify that quantum mechanics cannot be reduced to…

Mathematical Physics · Physics 2012-01-17 Jerzy Kocik

Given a bipartite quantum system represented by a tensor product of two Hilbert spaces, we give an elementary argument showing that if either component space is infinite-dimensional, then the set of nonseparable density operators is…

Quantum Physics · Physics 2009-10-31 Rob Clifton , Hans Halvorson

Derivation of two-time second-order correlation function by following approaches such as stochastic differential equation, coherent-state propagator, and quasi-statistical distribution function is presented. In the process, the time…

Quantum Physics · Physics 2024-06-18 Sintayehu Tesfa

Operators in quantum mechanics - either observables, density or evolution operators, unitary or not - can be represented by c-numbers in operator bases. The position and momentum bases are in one to one correspondence with lagrangian planes…

Quantum Physics · Physics 2018-08-03 Marcos Saraceno , Alfredo M. Ozorio de Almeida

The density operators obtained by taking partial traces do not represent proper mixtures of the subsystems of a compound physical system, but improper mixtures, since the coefficients in the convex sums expressing them never bear the…

Quantum Physics · Physics 2015-05-13 Fabio Masillo , Giuseppe Scolarici , Sandro Sozzo