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We call an operator algebra A {\em reversible} if A with reversed multiplication is also an abstract operator algebra (in the modern operator space sense). This class of operator algebras is intimately related to the {\em symmetric operator…

Operator Algebras · Mathematics 2025-11-24 David P. Blecher

Unitary operations are physically implementable. We further the understanding of such operations by studying the possible forms of nonlocal unitary operators, which are bipartite or multipartite unitary operators that are not tensor product…

Quantum Physics · Physics 2014-10-22 Lin Chen , Li Yu

Parity of particle number is a new degree of freedom for manipulating metasurface, while its influence on controlling non-local metasurfaces remains an unresolved and intriguing question. We propose a metasurface consisting of periodically…

Optics · Physics 2024-09-04 Hao Song , Xuelian Zhang , Yanming Sun , Guo Ping Wang

We study reflexivity and structure properties of operator algebras generated by representations of the discrete Heisenberg semi-group. We show that the left regular representation of this semi-group gives rise to a semi-simple reflexive…

Operator Algebras · Mathematics 2014-07-15 M. Anoussis , A. Katavolos , I. G. Todorov

Positivity of the density operator reflects itself in terms of sequences of inequalities on observable moments. Uncertainty relations for non-commuting observables form a subset of these inequalities. In addition, criterion of positivity…

Quantum Physics · Physics 2008-12-21 A R Usha Devi , A K Rajagopal

We derive necessary and sufficient conditions for local unitary (LU) operators to leave invariant the set of 1-qubit reduced density matrices of a multi-qubit state. LU operators with this property are tensor products of {\it cyclic local}…

Quantum Physics · Physics 2014-07-17 A. M. Martins

Negativity in a quasiprobability representation is typically interpreted as an indication of nonclassical behavior. However, this does not preclude states that are non-negative from exhibiting phenomena typically associated with quantum…

Quantum Physics · Physics 2012-08-23 Joel J. Wallman , Stephen D. Bartlett

This work focuses on non-compact groups and their applications to quantum gravity, mainly through the use of tensor operators. First, the mathematical theory of tensor operators for a Lie group is recast in a new way which is used to…

Mathematical Physics · Physics 2016-09-27 Giuseppe Sellaroli

We formulate N-fold supersymmetry in quantum mechanical systems with reflection operators. As in the cases of other systems, they possess the two significant characters of N-fold supersymmetry, namely, almost isospectrality and weak…

Mathematical Physics · Physics 2012-08-15 Toshiaki Tanaka

This paper is devoted to the construction and analysis of the Wigner functions for noncommutative quantum mechanics, their marginal distributions and star-products, following a technique developed earlier, {\it viz\/,} using the unitary…

Mathematical Physics · Physics 2015-12-02 S. Hasibul Hassan Chowdhury , S. Twareque Ali

The inherent challenge of detecting symmetries stems from arbitrary orientations of symmetry patterns; a reflection symmetry mirrors itself against an axis with a specific orientation while a rotation symmetry matches its rotated copy with…

Computer Vision and Pattern Recognition · Computer Science 2022-04-01 Ahyun Seo , Byungjin Kim , Suha Kwak , Minsu Cho

Given a unital inclusion of simple $C^*$-algebras equipped with a conditional expectation of index-finite type, we study Fourier transforms and rotation operators and introduce the reflection operators on the relative commutants. We prove…

Operator Algebras · Mathematics 2026-01-19 Keshab Chandra Bakshi , Satyajit Guin , Biplab Pal , Sruthymurali

Antiunitary representations of Lie groups take values in the group of unitary and antiunitary operators on a Hilbert space H. In quantum physics, antiunitary operators implement time inversion or a PCT symmetry, and in the modular theory of…

Representation Theory · Mathematics 2017-04-06 Karl-Hermann Neeb , Gestur Olafsson

We investigate the relation between local unitary symmetries and entanglement invariants of multi-qubit systems. The Hilbert space of such systems can be stratified in terms of states with different types of symmetry. We review the…

Quantum Physics · Physics 2014-11-04 Markus Johansson

We analyze status of ${\bf C}$, ${\bf P}$ and ${\bf T}$ discrete symmetries in application to neutron-antineutron transitions breaking conservation of baryon charge ${\cal B}$ by two units. At the level of free particles all these…

High Energy Physics - Phenomenology · Physics 2018-11-21 Zurab Berezhiani , Arkady Vainshtein

We refine recent local unitary entanglement classification for symmetric pure states of $n$ qubits (that is, states invariant under permutations of qubits) using local unitary stabilizer subgroups and Majorana configurations. Stabilizer…

Quantum Physics · Physics 2010-11-25 Curt D. Cenci , David W. Lyons , Scott N. Walck

In the previous two parts of this series of papers, we introduced and studied a large class of analytic difference operators admitting reflectionless eigenfunctions, focusing on algebraic and function-theoretic features in the first part,…

Exactly Solvable and Integrable Systems · Physics 2015-06-26 S. N. M. Ruijsenaars

Decompositions of the unitary group U(n) are useful tools in quantum information theory as they allow one to decompose unitary evolutions into local evolutions and evolutions causing entanglement. Several recursive decompositions have been…

Quantum Physics · Physics 2009-11-13 Mehmet Dagli , Domenico D'Alessandro , Jonathan D. H. Smith

In a recent article the authors showed that the radiative Transfer equations with multiple frequencies and scattering can be formulated as a nonlinear integral system. In the present article, the formulation is extended to handle reflective…

Numerical Analysis · Mathematics 2023-06-12 Olivier Pironneau , Pierre-Henri Tournier

We prove that the vast majority of symmetric states of qubits can be decomposed in a unique way into a superposition of spin 1/2 coherent states. For the case of two qubits, the proposed decomposition reproduces the Schmidt decomposition…

Quantum Physics · Physics 2015-06-25 A. Mandilara , T. Coudreau , A. Keller , P. Milman