English
Related papers

Related papers: Continuous model theories for von Neumann algebras

200 papers

We introduce a version of logic for metric structures suitable for applications to C*-algebras and tracial von Neumann algebras. We also prove a purely model-theoretic result to the effect that the theory of a separable metric structure is…

Logic · Mathematics 2013-07-16 Ilijas Farah , Bradd Hart , David Sherman

We survey the developments in the model theory of tracial von Neumann algebras that have taken place in the last fifteen years. We discuss the appropriate first-order language for axiomatizing this class as well as the subclass of II$_1$…

Logic · Mathematics 2022-10-28 Isaac Goldbring , Bradd Hart

We introduce pseudofinite W*-probability spaces. These are W*-probability spaces that are elementarily equivalent to Ocneanu ultraproducts of finite-dimensional von Neumann algebras equipped with arbitrary faithful normal states. We are…

Operator Algebras · Mathematics 2026-02-16 Jananan Arulseelan

This paper collates, presents, and expands upon technology and results obtained as part of the author's PhD thesis. We generalize work done in the $\sigma$-finite setting by the author, Goldbring, Hart, and Sinclair by producing a language…

Operator Algebras · Mathematics 2025-08-26 Jananan Arulseelan

By the Gelfand-Naimark theorem, any C*-algebra is isometrically isomorphic to a *-algebra of bounded operators on a Hilbert space which is closed with respect to the topology induced by the operator norm. Hence, the C*-algebras furnish an…

Operator Algebras · Mathematics 2020-09-15 Clemens Schindler

This paper includes a series of structural results for von Neumann algebras arising from measure preserving actions by product groups on probability spaces. Expanding upon the methods used earlier by the first two authors \cite{CS}, we…

Operator Algebras · Mathematics 2013-07-19 Ionut Chifan , Thomas Sinclair , Bogdan Udrea

In a previous paper we showed how the main theorems characterizing operator algebras and operator modules, fit neatly into the framework of the `noncommutative Shilov boundary', and more particularly via the left multiplier operator algebra…

Operator Algebras · Mathematics 2007-05-23 David P. Blecher

We prove continuous-valued analogues of the basic fact that Murray-von Neumann subequivalence of projections in II$_1$ factors is completely determined by tracial evaluations. We moreover use this result to solve the so-called trace problem…

Operator Algebras · Mathematics 2025-09-16 Ilijas Farah , Andrea Vaccaro

We introduce a new class of operator algebras -- tracially complete C*-algebras -- as a vehicle for transferring ideas and results between C*-algebras and their tracial von Neumann algebra completions. We obtain structure and classification…

We investigate some subtle and interesting phenomena in the duality theory of operator spaces and operator algebras. In particular, we give several applications of operator space theory, based on the surprising fact that certain maps are…

Operator Algebras · Mathematics 2007-05-23 David P. Blecher , Bojan Magajna

We adapt a continuous logic axiomatization of tracial von Neumann algebras due to Farah, Hart and Sherman in order to prove a metatheorem for this class of structures in the style of proof mining, a research program that aims to obtain the…

Logic · Mathematics 2022-11-17 Liviu Paunescu , Andrei Sipos

In the given article it is introduced new notions of a C$^*$-algebra of von Neumann type I and C$^*$-algebras of types I$_n$, II, II$_1$, II$_\infty$ and III. It is proved that any GCR-algebra is a C$^*$-algebra of von Neumann type I, and a…

Operator Algebras · Mathematics 2015-08-18 Arzikulov Farhodjon

We generalize Kirchberg's weak exactness to inclusions of C*-algebras in von Neumann algebras and study some characterizations and permanence properties which are similar to those of exact groups. We then consider a similar condition to…

Operator Algebras · Mathematics 2014-01-28 Yusuke Isono

We study some general properties of tracial C*-algebras. In the first part, we consider Dixmier type approximation theorem and characterize symmetric amenability for C*-algebras. In the second part, we consider continuous bundles of tracial…

Operator Algebras · Mathematics 2015-01-27 Narutaka Ozawa

We prove a strong dichotomy for the number of ultrapowers of a given countable model associated with nonprincipal ultrafilters on N. They are either all isomorphic, or else there are $2^{2^{\aleph_0}}$ many nonisomorphic ultrapowers. We…

Logic · Mathematics 2009-12-03 Ilijas Farah , Saharon Shelah

We study several notions of ultraproducts of von Neumann algebras from a unifying viewpoint. In particular, we show that for a sigma-finite von Neumann algebra $M$, the ultraproduct $M^{\omega}$ introduced by Ocneanu is a corner of the…

Operator Algebras · Mathematics 2014-03-25 Hiroshi Ando , Uffe Haagerup

Let M be a factor of type III with separable predual and with normal states phi_1,...,phi_k, omega with omega faithful. Let A be a finite dimensional C*-subalgebra of M. Then it is shown that there is a unitary operator u in M such that…

Operator Algebras · Mathematics 2014-02-26 Yasuyuki Kawahigashi , Yoshiko Ogata , Erling Størmer

We begin the systematic model theoretic study of $\mathrm{C}^*$-algebras using the tools of continuous logic.

Logic · Mathematics 2018-04-17 I. Farah , B. Hart , M. Lupini , L. Robert , A. Tikuisis , A. Vignati , W. Winter

We study several model-theoretic aspects of W$^*$-probability spaces, that is, $\sigma$-finite von Neumann algebras equipped with a faithful normal state. We first study the existentially closed W$^*$-spaces and prove several structural…

Operator Algebras · Mathematics 2022-04-26 Isaac Goldbring , Cyril Houdayer

Analogous to subfactor theory, employing Watatani's notions of index and $C^*$-basic construction of certain inclusions of $C^*$-algebras, (a) we develop a Fourier theory (consisting of Fourier transforms, rotation maps and shift operators)…

Operator Algebras · Mathematics 2026-01-01 Keshab Chandra Bakshi , Ved Prakash Gupta
‹ Prev 1 2 3 10 Next ›