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Related papers: Non-commutative perspectives

200 papers

We develop a general theory of operator realizations, or ``linear representations" of analytic functions in several non-commuting variables about a matrix-centre. In particular we show that a non-commutative function has a matrix-centre…

Functional Analysis · Mathematics 2025-09-12 Ali Karoobi , Robert T. W. Martin , Maximilian Tornes

This article, addressed to a general audience of functional analysts, is intended to be an illustration of a few basic principles from `noncommutative functional analysis', more specifically the new field of {\em operator spaces.} In our…

Functional Analysis · Mathematics 2007-05-23 David P. Blecher , Damon M. Hay

We introduce a new and extensive theory of noncommutative convexity along with a corresponding theory of noncommutative functions. We establish noncommutative analogues of the fundamental results from classical convexity theory, and apply…

Operator Algebras · Mathematics 2025-06-11 Kenneth R. Davidson , Matthew Kennedy

We investigate the geode and some of its generalizations from the point of view on noncommutative symmetric functions.

Combinatorics · Mathematics 2026-01-29 Jean-Christophe Novelli , Jean-Yves Thibon

We propose a notion of operator monotonicity for functions of several variables, which extends the well known notion of operator monotonicity for functions of only one variable. The notion is chosen such that a fundamental relationship…

Operator Algebras · Mathematics 2007-05-23 Frank Hansen

Any maximal monotone operator can be characterized by a convex function. The family of such convex functions is invariant under a transformation connected with the Fenchel-Legendre conjugation. We prove that there exist a convex…

Functional Analysis · Mathematics 2008-03-11 B. F. Svaiter

We present a concise proof for the supporting hyperplane theorem. We then observe that the proof not only establishes the supporting hyperplane theorem but also extends it to a hyperplane separation theorem for certain non-convex sets. The…

Optimization and Control · Mathematics 2023-10-10 Ali Taherinassaj , Yiling Chen

In this paper, we consider the locally convex spaces of entire functions with growth given by proximate orders, and study the representation as a differential operator of a continuous homomorphism from such a space to another one. As a…

Functional Analysis · Mathematics 2020-03-26 Takashi Aoki , Ryuichi Ishimura , Yasunori Okada

We prove a strengthened form of convexity for operator monotone decreasing positive functions defined on the positive real numbers. This extends Ando and Hiai's work to allow arbitrary positive maps instead of states (or the identity map),…

Functional Analysis · Mathematics 2021-06-03 Megumi Kirihata , Makoto Yamashita

We discuss non-commutative field theories in coordinate space. To do so we introduce pseudo-localized operators that represent interesting position dependent (gauge invariant) observables. The formalism may be applied to arbitrary field…

High Energy Physics - Theory · Physics 2007-05-23 David Berenstein , Robert G. Leigh

A certain special function of the generalized hypergeometric variety is shown to fulfill a host of useful noncommutative identities.

Quantum Algebra · Mathematics 2015-06-26 A. Yu. Volkov

Abstract convexity generalises classical convexity by considering the suprema of functions taken from an arbitrarily defined set of functions. These are called the abstract linear (abstract affine) functions. The purpose of this paper is to…

Optimization and Control · Mathematics 2025-01-30 Reinier Diàz Millàn , Nadezda Sukhorukova , Julien Ugon

Starting with the first-order singular Lagrangian containing the redundant variables, the noncommutative quantum mechanics on a curved space is investigated by the constraint star-product quantization formalism of the projection operator…

High Energy Physics - Theory · Physics 2016-10-06 M. Nakamura

In this paper we establish a multivariable non-commutative generalization of L\"owner's classical theorem from 1934 characterizing operator monotone functions as real functions admitting analytic continuation mapping the upper complex…

Functional Analysis · Mathematics 2016-06-14 Miklós Pálfia

We introduce notions of concavity for functions on balanced polyhedral spaces, and we show that concave functions on such spaces satisfy several strong continuity properties.

Combinatorics · Mathematics 2021-09-14 Ana María Botero , José Ignacio Burgos Gil , Martín Sombra

In this article we utilise abstract convexity theory in order to unify and generalize many different concepts from nonsmooth analysis. We introduce the concepts of abstract codifferentiability, abstract quasidifferentiability and abstract…

Optimization and Control · Mathematics 2018-10-03 M. V. Dolgopolik

A natural extension of the standard model within non-commutative geometry is presented. The geometry determines its Higgs sector. This determination is fuzzy, but precise enough to be incompatible with experiment.

High Energy Physics - Theory · Physics 2014-11-18 Igor Pris , Thomas Schucker

Properties of compositions and convex combinations of averaged nonexpansive operators are investigated and applied to the design of new fixed point algorithms in Hilbert spaces. An extended version of the forward-backward splitting…

Functional Analysis · Mathematics 2014-10-09 Patrick L. Combettes , Isao Yamada

The Koopman operator provides a linear perspective on non-linear dynamics by focusing on the evolution of observables in an invariant subspace. Observables of interest are typically linearly reconstructed from the Koopman eigenfunctions.…

Dynamical Systems · Mathematics 2024-03-06 Shaowu Pan , Karthik Duraisamy

We develop a dilation theory for row contractions subject to constraints determined by sets of noncommutative polynomials. Under natural conditions on the constraints, we have uniqueness for the minimal dilation. A characteristic function…

Operator Algebras · Mathematics 2007-05-23 Gelu Popescu