English
Related papers

Related papers: Projections from a von~Neumann algebra onto a suba…

200 papers

Let M be a von Neumann algebra on a Hilbert space H with a cyclic and separating unit vector \Omega and let \omega be the faithful normal state on M given by \omega(\cdot)=(\Omega,\cdot\Omega). Moreover, let {N_i :i\in I} be a family of von…

Operator Algebras · Mathematics 2018-10-16 Sebastiano Carpi

Given a type I von Neumann algebra $M$ with a faithful normal semi-finite trace $\tau,$ let $S_0(M, \tau)$ be the algebra of all $\tau$-compact operators affiliated with $M.$ We give a complete description of all derivations on the algebra…

Operator Algebras · Mathematics 2008-07-29 S. Albeverio , Sh. A. Ayupov , K. K. Kudaybergenov , T. S. Kalandarov

The algebra of Noether supercharges of the M-5-brane effective action is shown to include both 2-form and 5-form central charges. Surprisingly, only the 5-form charge is entirely due to the Wess-Zumino term because the `naive' algebra is…

High Energy Physics - Theory · Physics 2009-10-30 Dmitri Sorokin , Paul K. Townsend

We revisit Haagerup's enigmatic reduction theorem \cite[Theorems 2.1 \& 3.1]{HJX} showing how that theorem may be extended to general von Neumann algebras $\M$ equipped with an arbitrary faithful normal semifinite weight in a manner which…

Operator Algebras · Mathematics 2025-06-10 Louis Labuschagne , Quanhua Xu

In this paper, we introduce the notion of strict projections and prove that an absolutely compatible pair of strict elements in a von Neumann algebra $\mathcal{M}$ unitarily equivalent to the elements $ \left((p - x_0) \otimes I_2 \right)…

Operator Algebras · Mathematics 2021-10-26 Anil Kumar Karn

The dimension of any module over an algebra of affiliated operators ${\mathcal U}$ of a finite von Neumann algebra ${\mathcal A}$ is defined using a trace on ${\mathcal A}.$ All zero-dimensional ${\mathcal U}$-modules constitute the torsion…

Rings and Algebras · Mathematics 2010-09-14 Lia Vas

In this dissertation we study the category of completely positive normal contractive maps between von Neumann algebras. It includes an extensive introduction to the basic theory of $C^*$-algebras and von Neumann algebras.

Operator Algebras · Mathematics 2019-03-28 Abraham A. Westerbaan

We examine the problem of projecting subsets of a commutative, positively ordered monoid into an $o$-ideal. We prove that to this end one may restrict to a sufficient subset, for whose cardinality we provide an explicit upper bound. Several…

Commutative Algebra · Mathematics 2022-08-25 Gianluca Cassese

The main goal of this paper is to find operator algebra variants of certain deep results of Stormer, Friedman and Russo, Choi and Effros, Effros and Stormer, Robertson and Youngson, Youngson, and others, concerning projections on…

Operator Algebras · Mathematics 2016-07-06 David P. Blecher , Matthew Neal

We prove that the multiplication of sections of globally generated line bundles on a model wonderful variety M of simply connected type is always surjective. This follows by a general argument which works for every wonderful variety and…

Algebraic Geometry · Mathematics 2018-06-26 Paolo Bravi , Jacopo Gandini , Andrea Maffei

Let $\Lambda$ be an Auslander's 1-Gorenstein Artinian algebra with global dimension two. If $\Lambda$ admits a trivial maximal 1-orthogonal subcategory of $\mod\Lambda$, then for any indecomposable module $M \in \mod \Lambda$, we have that…

Representation Theory · Mathematics 2009-06-21 Zhaoyong Huang , Xiaojin Zhang

Given positive linear functional l on a vector lattice L of real functions, and a vector subspace M of L, we construct a vector subspace P(M) of M in such a way that 1) l is nullcontinuous on P(M), and 2) if l is nullcontinuous on M then…

Functional Analysis · Mathematics 2007-05-23 Marco Thill

Let $M$ be a Carath\'eodory hyperbolic complex manifold. We show that $M$ supports a real-analytic bounded strictly plurisubharmonic function. If $M$ is also complete K\"ahler, we show that $M$ admits the Bergman metric. When $M$ is…

Complex Variables · Mathematics 2025-01-20 Kwok-Kin Wong , Sai-Kee Yeung

We introduce a notion of a connection on a coherent sheaf on a weighted projective line (in the sense of Geigle and Lenzing). Using a theorem of Huebner and Lenzing we show, under a mild hypothesis, that if one considers coherent sheaves…

Algebraic Geometry · Mathematics 2009-04-23 William Crawley-Boevey

An open question, raised independently by several authors, asks if a closed amenable subalgebra of ${\mathcal B}({\mathcal H})$ must be similar to an amenable C*-algebra; the question remains open even for singly-generated algebras. In this…

Operator Algebras · Mathematics 2013-05-07 Yemon Choi

The aim of this paper and its prequel is to introduce and classify the irreducible holonomy algebras of the projective Tractor connection. This is achieved through the construction of a `projective cone', a Ricci-flat manifold one dimension…

Differential Geometry · Mathematics 2007-05-23 Stuart Armstrong

We introduce a similarity relation between submodules of a module $M$ over a ring $R$, extending the classical notion of similarity for right ideals. Focusing on (faithfully) projective modules, we establish a sharp lower bound for the…

Rings and Algebras · Mathematics 2026-04-07 Alborz Azarang

In this paper, for a C*-Algebra A with M = M(A) an AW*-algebra, or equivalently, for an essential, norm-closed, two-sided ideal A of an AW*-algebra M, we investigate the strict approximability of the elements of M from commutative C*-…

Operator Algebras · Mathematics 2007-05-23 Claudio D'Antoni , Laszlo Zsido

We prove that the projective model structure on the category of unbounded cochain complexes extends naturally to the category of contractions. The proof is completely elementary and we do not assume familiarity with model categories.

Algebraic Topology · Mathematics 2017-03-10 Marco Manetti , Chiara Spagnoli

This paper is devoted to derivations on the algebra $S_0(M, \tau)$ of all $\tau$-compact operators affiliated with a von Neumann algebra $M$ and a faithful normal semi-finite trace $\tau.$ The main result asserts that every…

Operator Algebras · Mathematics 2013-09-10 Shavkat Ayupov , Karimbergen Kudaybergenov