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Phase retrieval has become a very active area of research. We will classify when phase retrieval by Parseval frames passes to the Naimark complement and when phase retrieval by projections passes to the orthogonal complements. We introduce…

Functional Analysis · Mathematics 2014-09-30 Saeid Bahmanpour , Jameson Cahill , Peter G. Casazza , John Jasper , Lindsey M. Woodland

In its most general formulation a quantum kinematical system is described by a Heisenberg group; the "configuration space" in this case corresponds to a maximal isotropic subgroup. We study irreducible models for Heisenberg groups based on…

Quantum Algebra · Mathematics 2007-05-23 T. Digernes , V. S. Varadarajan

The change of a quantum state can generally only be fully monitored through simultaneous measurements of two non-commuting observables X and Y spanning a phase space. A measurement device that is coupled to the thermal environment provides…

Quantum Physics · Physics 2021-04-20 Jascha Zander , Roman Schnabel

The finite Heisenberg group knows when the dimension of Hilbert space is a square number. Remarkably, it then admits a representation such that the entire Clifford group --- the automorphism group of the Heisenberg group --- is represented…

Quantum Physics · Physics 2012-02-17 Ingemar Bengtsson

Let $X$ and $Y$ be real normed spaces and $f \colon X\to Y$ a surjective mapping. Then $f$ satisfies $\{\|f(x)+f(y)\|, \|f(x)-f(y)\|\} = \{\|x+y\|, \|x-y\|\}$, $x,y\in X$, if and only if $f$ is phase equivalent to a surjective linear…

Functional Analysis · Mathematics 2020-11-16 Aleksej Turnsek , Dijana Ilisevic , Matjaz Omladic

Necessary and sufficient conditions for a group to possess a faithful irreducible representation are investigated

Representation Theory · Mathematics 2016-11-01 Fernando Szechtman , Anatoliy Tushev

Consider a generic $r$-dimensional subspace of $\mathbb{R}^d$, $r<d$, and suppose that we are only given projections of this subspace onto small subsets of the canonical coordinates. The paper establishes necessary and sufficient…

Machine Learning · Statistics 2016-02-22 Daniel L. Pimentel-Alarcón , Robert D. Nowak , Nigel Boston

We characterize all the phase space measurements for a non-relativistic particle.

Quantum Physics · Physics 2007-05-23 C. Carmeli , G. Cassinelli , E. DeVito , A. Toigo , B. Vacchini

Identities of complex irreducible representations of finite groups can be explicitly constructed from character value sets. Among other things, these identities determine representations up to Gassmann equivalency. Some examples of…

Representation Theory · Mathematics 2026-01-05 Alexander Kushkuley

We investigate the most general "phase space" of configurations, consisting of all possible ways of assigning elementary attributes, "energies", to elementary positions, "cells". We discuss how this space possesses structures that can be…

High Energy Physics - Theory · Physics 2009-02-09 Andrea Gregori

We show pro-definability of spaces of definable types in various classical complete first order theories, including complete o-minimal theories, Presburger arithmetic, $p$-adically closed fields, real closed and algebraically closed valued…

Logic · Mathematics 2022-08-09 Pablo Cubides Kovacsics , Jinhe Ye

We study plane quadratic and cubic differential systems satisfying the Caushy - Riemann conditions. We construct all global topologically equivalent phase portraits of the systems.

Dynamical Systems · Mathematics 2014-12-02 E. P. Volokitin , S. A. Treskov , V. V. Cheresiz

Fundamental phase-shift detection properties of optical multimode interferometers are analyzed. Limits on perfectly distinguishable phase shifts are derived for general quantum states of a given average energy. In contrast to earlier work,…

Quantum Physics · Physics 2008-12-18 Jonas Soderholm , Gunnar Bjork , Bjorn Hessmo , Shuichiro Inoue

We show that coorbit spaces can be characterized in terms of arbitrary phase-space covers, which are families of phase-space multipliers associated with partitions of unity. This generalizes previously known results for time-frequency…

Functional Analysis · Mathematics 2015-04-27 José Luis Romero

Within the setting of algebraic quantum field theory a relation between phase-space properties of observables and charged fields is established. These properties are expressed in terms of compactness and nuclearity conditions which are the…

High Energy Physics - Theory · Physics 2016-09-06 D. Buchholz , C. D'Antoni

We show that number and canonical phase (of a single mode optical field) are complementary observables. We also bound the measurement uncertainty region for their approximate joint measurements.

Quantum Physics · Physics 2018-02-05 Pekka Lahti , Juha-Pekka Pellonpää , Jussi Schultz

We apply persistent homology to the task of discovering and characterizing phase transitions, using lattice spin models from statistical physics for working examples. Persistence images provide a useful representation of the homological…

Statistical Mechanics · Physics 2020-12-03 Alex Cole , Gregory J. Loges , Gary Shiu

We address the problem of finding necessary and sufficient conditions for an arbitrary group, not necessarily finite, to admit a faithful irreducible representation over an arbitrary field.

Representation Theory · Mathematics 2016-01-13 Fernando Szechtman

Phase space quasi-probability functions provide powerful representations of quantum states and operators, as well as criteria for assessing quantum computational resources. In discrete, odd-dimensional systems (qudits), protocols involving…

Quantum Physics · Physics 2025-12-08 Eloi Descamps , Astghik Saharyan , Arne Keller , Pérola Milman

This contribution to the present Workshop Proceedings outlines a general programme for identifying geometric structures--out of which to possibly recover quantum dynamics as well--associated to the manifold in Hilbert space of the quantum…

Quantum Physics · Physics 2018-06-28 Jan Govaerts