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We develop a Heisenberg-picture \emph{kinematical} framework in which (i) time is treated as a quantum observable, admitting both a relational POVM construction for semibounded spectra and a fully self-adjoint realization on an enlarged…

General Physics · Physics 2026-03-17 Vahid Kamali

Starting from a Unified Field Theory (UFT) proposed previously by the author, the possible fermionic representations arising from the same spacetime are considered from the algebraic and geometrical viewpoint. We specifically demonstrate in…

High Energy Physics - Theory · Physics 2015-03-17 Diego Julio Cirilo-Lombardo

We construct local, boost covariant boundary QFT nets of von Neumann algebras on the interior of the Lorentz hyperboloid LH = {x^2 - t^2 > R^2, x>0}, in the two-dimensional Minkowski spacetime. Our first construction is canonical, starting…

Mathematical Physics · Physics 2012-04-30 Roberto Longo , Karl-Henning Rehren

In this article, we give a definition for measured quantum groupoids. We want to get objects with duality extending both quantum groups and groupoids. We base ourselves on J. Kustermans and S. Vaes' works about locally compact quantum…

Operator Algebras · Mathematics 2007-05-23 Franck Lesieur

Let E be an operator algebra on a Hilbert space with finite-dimensional generated C*-algebra. A classification is given of the locally finite algebras and the operator algebras obtained as limits of direct sums of matrix algebras over E…

Operator Algebras · Mathematics 2007-05-23 S. C. Power

We complete the classification of symmetry constraints on gapped quadratic fermion hamiltonians proposed by Kitaev. The symmetry group is supposed compact and can include arbitrary unitary or antiunitary operators in the Fock space that…

Mathematical Physics · Physics 2011-05-19 Gilles Abramovici , Pavel Kalugin

We revisit the work of Rieffel and van Daele on pairs of subspaces of a real Hilbert space, while relaxing as much as possible the assumption that all the relevant subspaces are in general positions with respect to each other. We work out,…

Mathematical Physics · Physics 2025-03-10 Jan Naudts , Jun Zhang

We reconsider differential geometry from the point of view of the quantum theory of non-relativistic spinning particles, which provides examples of supersymmetric quantum mechanics. This enables us to encode geometrical structure in…

High Energy Physics - Theory · Physics 2016-09-06 J. Froehlich , O. Grandjean , A. Recknagel

We perform Wigner analysis of linear operators. Namely, the standard time-frequency representation \emph{Short-time Fourier Transform} (STFT) is replaced by the $\mathcal{A}$-\emph{Wigner distribution} defined by $W_{\mathcal A}…

Analysis of PDEs · Mathematics 2021-08-10 Elena Cordero , Luigi Rodino

A unitary representation of a, possibly infinite dimensional, Lie group $G$ is called semibounded if the corresponding operators $i\dd\pi(x)$ from the derived representation are uniformly bounded from above on some non-empty open subset of…

Representation Theory · Mathematics 2012-05-24 Karl-Hermann Neeb

This is mainly a lecture note taken by myself following Weinberg's book, but also contains some corrections to the abuse of mathematical treatment. This article discusses projective unitary representations of Poincare group on the single…

Mathematical Physics · Physics 2023-02-28 Zixuan Feng

In this paper, we give an alternative approach to the theory of locally compact quantum groups, as developed by Kustermans and Vaes. We develop the theory completely within the von Neumann algebra framework. At various points, we also do…

Operator Algebras · Mathematics 2014-08-07 Alfons Van Daele

We extend the framework of general boundary quantum field theory (GBQFT) to achieve a fully local description of realistic quantum field theories. This requires the quantization of non-K\"ahler polarizations which occur generically on…

High Energy Physics - Theory · Physics 2021-07-27 Daniele Colosi , Robert Oeckl

This work reconsiders the holomorphic and anti-holomorphic Dirac operators of Hermitian Clifford analysis to determine whether or not they are the natural generalization of the orthogonal Dirac operator to spaces with complex structure. We…

Representation Theory · Mathematics 2016-11-02 Stuart Shirrell , Raymond Walter

We study self-adjoint semigroups of partial isometries on a Hilbert space. These semigroups coincide precisely with faithful representations of abstract inverse semigroups. Groups of unitary operators are specialized examples of…

Functional Analysis · Mathematics 2013-06-13 Alexey I. Popov , Heydar Radjavi

The role of the modular group in the holonomy representation of (2+1)-dimensional quantum gravity is studied. This representation can be viewed as a "Heisenberg picture", and for simple topologies, the transformation to the ADM…

General Relativity and Quantum Cosmology · Physics 2010-04-28 S. Carlip , J. E. Nelson

In the Hilbert space formulation of classical mechanics (CM), pioneered by Koopman and von Neumann (KvN), there are potentially more observables that in the standard approach to CM. In this paper we show that actually many of those extra…

Quantum Physics · Physics 2014-11-21 ennio gozzi , carlo pagani

We formulate the unitary rational orbifold conformal field theories in the algebraic quantum field theory framework. Under general conditions, we show that the orbifold of a given unitary rational conformal field theories generates a…

Quantum Algebra · Mathematics 2009-10-31 Feng Xu

We identify a means to explicitly construct primary operators of free conformal field theories (CFTs) in spacetime dimensions $d=2,~3$, and $4$. Working in momentum space with spinors, we find that the $N$-distinguishable-particle Hilbert…

High Energy Physics - Theory · Physics 2019-02-20 Brian Henning , Tom Melia

Symmetries in quantum mechanics are realized by the projective representations of the Lie group as physical states are defined only up to a phase. A cornerstone theorem shows that these representations are equivalent to the unitary…

Quantum Physics · Physics 2012-01-16 S. G. Low , P. D. Jarvis , R. Campoamor-Stursberg