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Operator convex functions defined on the positive half-line play a prominent role in the theory of quantum information, where they are used to define quantum $f$-divergences. Such functions admit integral representations in terms of…

Optimization and Control · Mathematics 2023-05-23 Oisín Faust , Hamza Fawzi

Any polarization vector of a plane wave can be decomposed into a pair of mutually orthogonal base vectors, known as a polarization basis. Regarding this decomposition as a quasi-unitary transformation from a three-component vector to a…

Optics · Physics 2010-11-17 Chun-Fang Li , Xi Chen

We consider elliptic second order partial differential operators with Lipschitz continuous leading order coefficients on finite cubes and the whole Euclidean space. We prove quantitative sampling and equidistribution theorems for…

Analysis of PDEs · Mathematics 2025-05-23 Martin Tautenhahn , Ivan Veselic

We study the tomography of propagators for spin systems in the context of finite-dimensional Wigner representations, which completely characterize and visualize operators using shapes assembled from linear combinations of spherical…

Quantum Physics · Physics 2018-07-12 David Leiner , Steffen J. Glaser

The relative distance between eigenvalues of the compression of a not necessarily semibounded self-adjoint operator to a closed subspace and some of the eigenvalues of the original operator in a gap of the essential spectrum is considered.…

Spectral Theory · Mathematics 2024-07-23 Albrecht Seelmann

Operators for simulating the scattering of two particles with spin are constructed. Three methods are shown to give the consistent lattice operators for PN, PV, VN and NN scattering, where P, V and N denote pseudoscalar meson, vector meson…

High Energy Physics - Lattice · Physics 2016-10-05 S. Prelovsek , U. Skerbis , C. B. Lang

In this work we represent the $1/2$ Spin particles with complex quaternions using a transformation to 2x2 matrices in order to obtain the Pauli matrices. With this representation we determine the states, rotation operators and the total…

Quantum Physics · Physics 2024-03-06 Alejandro Arias Jiménez

We analyze in mathematical detail, within the framework of the QMUPL model of spontaneous wave function collapse, the von Neumann measurement scheme for the measurement of a 1/2 spin particle. We prove that, according to the equation of the…

Quantum Physics · Physics 2009-11-13 A. Bassi , D. G. M. Salvetti

To reconstruct a mixed or pure quantum state of a spin s is possible through coherent states: its density matrix is fixed by the probabilities to measure the value s along 4s(s+1) appropriately chosen directions in space. Thus, after…

Quantum Physics · Physics 2007-05-23 Stefan Weigert

It is shown that the components of Pryce's spin operator of Dirac's theory are $SU(2)$ generators of a representation carried by the space of Pauli's spinors determining the polarization of the plane wave solutions of Dirac's equation.…

Quantum Physics · Physics 2023-01-12 Ion I. Cotaescu

Recently it has been shown that the quantum spin-1/2 spin operators can be exactly transformed not only in spinless, but also in spinful canonical Fermi operators in 1D [\cite{JW1}], and 2D [\cite{JW2}] as well. In this paper, using the…

Strongly Correlated Electrons · Physics 2025-11-10 Zsolt Gulacsi

We derive bases of improved operators for all bilinear quark currents up to spin two (including the operators measuring the first moment of DIS Structure Functions), and compute their one-loop renormalization constants for arbitrary…

High Energy Physics - Lattice · Physics 2008-11-26 S. Capitani , M. Goeckeler , R. Horsley , H. Perlt , P. Rakow , G. Schierholz , A. Schiller

Form factors for local spin operators of the XXZ Heisenberg spin-1/2 finite chain are computed. Representation theory of Drinfel'd twists for the sl2 quantum affine algebra in finite dimensional modules is used to calculate scalar products…

Mathematical Physics · Physics 2018-08-30 N. Kitanine , J. M. Maillet , V. Terras

Different bases for the spin-1 density matrix are discussed to clarify the connection between its components and observables measured in heavy-ion collisions. The theoretical advantage of using the adjoint representation for spin matrices…

Nuclear Theory · Physics 2026-02-03 Wojciech Florkowski , Sudip Kumar Kar , Valeriya Mykhaylova

Recently, in the context of Relativistic Quantum Information Theory (RQI) of massive spin-1/2 particles, it has been suggested that it is impossible to perform a momentum-independent spin measurement, showing the inadequacy of the spin…

Mathematical Physics · Physics 2022-01-12 Heon Lee

We generalize the Gutzwiller wavefunction for s = 1/2 spin chains to construct a family of wavefunctions for all s > 1/2. Through numerical simulations, we demonstrate that the spin spin correlation functions for all s decay as a power law…

Strongly Correlated Electrons · Physics 2026-01-16 Onuttom Narayan , B. Sriram Shastry

Based on the concept of ensemble, it is proved in the manuscript that the probability amplitude function can also been used to describe the classical statistical system. The motion equations of probability amplitude functions of classical…

Classical Physics · Physics 2007-05-23 Xiaochun Mei

We study the interaction of a scalar and a spinning particle with a coherent linearized gravitational wave field treated as a classical spin two external field. The spin degrees of freedom of the spinning particle are described by…

High Energy Physics - Theory · Physics 2008-11-26 A. Barducci , R. Giachetti

The description of particles with spin can be attained by using a spin density matrix in high energy reaction. In this paper we present a parametrization of the spin density matrix for spin -3/2 particles in the Cartesian form. Comparing…

High Energy Physics - Phenomenology · Physics 2020-05-05 Jiao Jiao Song , Wan Ling Chang

Space of states of PT symmetrical quantum mechanics is examined. Requirement that eigenstates with different eigenvalues must be orthogonal leads to the conclusion that eigenfunctions belong to the space with an indefinite metric. The self…

Quantum Physics · Physics 2008-11-26 G. S. Japaridze