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Related papers: A planar algebraic description of conditional expe…

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We introduce a notion of planar algebra, the simplest example of which is a vector space of tensors, closed under planar contractions. A planar algebra with suitable positivity properties produces a finite index subfactor of a II_1 factor,…

Quantum Algebra · Mathematics 2007-05-23 Vaughan F. R. Jones

We prove that (a) the sections space of a continuous unital subhomogeneous $C^*$ bundle over compact metrizable $X$ admits a finite-index expectation onto $C(X)$, answering a question of Blanchard-Gogi\'{c} (in the metrizable case); (b)…

Operator Algebras · Mathematics 2025-11-04 Alexandru Chirvasitu

From a planar algebra, we give a functorial construction to produce numerous associated $C^*$-algebras. Our main construction is a Hilbert $C^*$-bimodule with a canonical real subspace which produces Pimsner-Toeplitz, Cuntz-Pimsner, and…

Operator Algebras · Mathematics 2014-01-14 Michael Hartglass , David Penneys

Let $M$ be a T-motive. We introduce the notion of duality for $M$. Main results of the paper (we consider uniformizable $M$ over $F_q[T]$ of rank $r$, dimension $n$, whose nilpotent operator $N$ is 0): 1. Algebraic duality implies analytic…

Number Theory · Mathematics 2019-02-06 A. Grishkov , D. Logachev

For an algebraic compact quantum group $H$ we establish a bijection between the set of right coideal $*$-subalgebras $A\to H$ and that of left module quotient $*$-coalgebras $H\to C$. It turns out that the inclusion $A\to H$ always splits…

Quantum Algebra · Mathematics 2018-07-16 Alexandru Chirvasitu

We study a finite index inclusion of simple unital C*-algebras and construct a canonical completely positive coproduct on the second relative commutant, thereby endowing it with a natural coalgebra structure. Motivated by this construction,…

Operator Algebras · Mathematics 2026-01-21 Keshab Chandra Bakshi , Debashish Goswami , Biplab Pal

This work is about the structure of the symbolic Rees algebra of the base ideal of a Cremona map. We give sufficient conditions under which this algebra has the "expected form" in some sense. The main theorem in this regard seemingly covers…

Commutative Algebra · Mathematics 2014-07-25 Barbara Costa , Zaqueu Ramos , Aron Simis

We consider a family of conditional nonlinear expectations defined on the space of bounded random variables and indexed by the class of all the sub-sigma-algebras of a given underlying sigma-algebra. We show that if this family satisfies a…

Mathematical Finance · Quantitative Finance 2025-06-04 Edoardo Berton , Alessandro Doldi , Marco Maggis

Most of this article is an expanded version of our conference talk. It is essentially a survey, but some part, like most of the lengthy Section 5, is comprised of new results whose proofs are unpublished elsewhere. We begin by reviewing the…

Operator Algebras · Mathematics 2020-09-17 David P. Blecher

In this paper, we show how a construction of an implicit complexity model can be implemented using concepts coming from the core of von Neumann algebras. Namely, our aim is to gain an understanding of classical computation in terms of the…

Computational Complexity · Computer Science 2009-12-31 Marco Pedicini , Mario Piazza

We prove implications among the conditions in the title for an inclusion of a C*-algebra A in a C*-algebra B, and we also relate this to several other properties in case B is a crossed product for an action of a group, inverse semigroup or…

Operator Algebras · Mathematics 2021-08-17 Bartosz Kosma Kwaśniewski , Ralf Meyer

Several notions of bisimulation relations for probabilistic non-deterministic transition systems have been considered in the literature. We consider a novel testing-based behavioral equivalence called upper-expectation bisimilarity and…

Logic in Computer Science · Computer Science 2013-10-03 Matteo Mio

A {\it W$^*$-representation} of a II$_1$ subfactor $N\subset M$ with finite Jones index, $[M:N]<\infty$, is a non-degenerate commuting square embedding of $N\subset M$ into an inclusion of atomic von Neumann algebras $\oplus_{i\in I} \Cal…

Operator Algebras · Mathematics 2022-07-12 Sorin Popa

A class of $C^*$-algebras, to be called those of generalized tracial rank one, is introduced, and classified by the Elliott invariant. A second class of unital simple separable amenable $C^*$-algebras, those whose tensor products with…

Operator Algebras · Mathematics 2020-12-08 Guihua Gong , Huaxin Lin , Zhuang Niu

Subfactor theory provides a tool to analyze and construct extensions of Quantum Field Theories, once the latter are formulated as local nets of von Neumann algebras. We generalize some of the results of [LR95] to the case of extensions with…

Operator Algebras · Mathematics 2018-04-11 Simone Del Vecchio , Luca Giorgetti

This paper characterizes the precision of index estimation as it carries over into precision of matching. In a model assuming Gaussian covariates and making best-case assumptions about matching quality, it sharply characterizes average and…

Methodology · Statistics 2023-01-11 Ben B. Hansen

We show that a QWEP von Neumann algebra has the weak* positive approximation property if and only if it is seemingly injective in the following sense: there is a factorization of the identity of $M$ $$Id_M=vu: M{\buildrel…

Operator Algebras · Mathematics 2023-04-05 Gilles Pisier

It is shown that the *-algebra of all (closed densely defined linear) operators affiliated with a finite type I von Neumann algebra admits a unique center-valued trace, which turns out to be, in a sense, normal. It is also demonstrated that…

Operator Algebras · Mathematics 2017-05-26 Piotr Niemiec , Adam Wegert

Let $M$ be a factor with separable predual and $G$ a compact group of automorphisms of $M$ whose action is minimal, i.e. $M^{G^\prime}\cap M = C$, where $M^G$ denotes the $G$-fixed point subalgebra. Then every intemediate von Neumann…

funct-an · Mathematics 2008-02-03 Masaki Izumi , Roberto Longo , Sorin Popa

We introduce the notion of confined subalgebras in the context of the group von Neumann algebra. We also define Uniformly Recurrent States -- an operator-algebraic analog of Uniformly Recurrent Subgroups. Using this framework, we show that…

Operator Algebras · Mathematics 2026-04-21 Tattwamasi Amrutam , Yongle Jiang