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We consider coherent sublinear expectations on a measurable space, without assuming the existence of a dominating probability measure. By considering a decomposition of the space in terms of the supports of the measures representing our…

Probability · Mathematics 2011-10-27 Samuel N. Cohen

It is known that every semigroup of normal completely positive maps $P = {P_t: t\geq 0}$ of $B(H)$, satisfying $P_t(1) = 1$ for every $t\geq 0$, has a minimal dilation to an E_0-semigroup acting on $B(K)$ for some Hilbert space K containing…

funct-an · Mathematics 2008-02-03 William Arveson

Let $P \subset A$ be a inclusion of unital C*-algebras and $E\colon A \to P$ be a conditional expectation of index finite type. We introduce a Rokhlin property for $E$ and discuss about $\mathcal{D}$-absorbing proeprty, where $\mathcal{D}$…

Operator Algebras · Mathematics 2010-02-24 Hiroyuki Osaka , Tamotsu Teruya

The aim of this article is to establish basic results in a conditional measure theory. The results are applied to prove that arbitrary kernels and conditional distributions are represented by measures in a conditional set theory. In…

Probability · Mathematics 2018-03-21 Asgar Jamneshan , Michael Kupper , Martin Streckfuß

Let $P \subset A$ be an inclusion of $\sigma$-unital C*-algebras with a finite index in the sense of Izumi. Then we introduce the Rokhlin property for a conditional expectation $E$ from $A$ onto $P$ and show that if $A$ is simple and…

Operator Algebras · Mathematics 2018-03-23 Hiroyuki Osaka , Tamotsu Teruya

Index maps taking values in the $K$-theory of a mapping cone are defined and discussed. The resulting index theorem can be viewed in analogy with the Freed-Melrose index theorem. The framework of geometric $K$-homology is used in a…

K-Theory and Homology · Mathematics 2016-03-11 Robin J. Deeley

Let $R$ be a commutative noetherian ring. We prove that the class of modules of projective dimension bounded by $k$ is of finite type if and only if $R$ satisfies Serre's condition $(S_k)$. In particular, this answers positively a question…

Commutative Algebra · Mathematics 2023-11-27 Michal Hrbek , Giovanna Le Gros

Let cp(R) be the probability that two random elements of a finite ring R commute and zp(R) the probability that the product of two random elements in R is zero. We show that if cp(R)=e, then there exists a Lie-ideal D in the Lie-ring…

Rings and Algebras · Mathematics 2023-07-25 Pavel Shumyatsky , Matteo Vannacci

We generalize Condition (K) from directed graphs to Boolean dynamical systems and show that a locally finite Boolean dynamical system $(\mathcal{B},\mathcal{L},\theta)$ with countable $\mathcal{B}$ and $\mathcal{L}$ satisfies Condition (K)…

Operator Algebras · Mathematics 2023-06-22 Toke Meier Carlsen , Eun Ji Kang

Let $G$ be a discrete group acting on a unital $C^*$-algebra $\mathcal{A}$ by $*$-automorphisms. We characterize (in terms of the dynamics) when the inclusion $\mathcal{A} \subseteq \mathcal{A} \rtimes_r G$ has a unique conditional…

Operator Algebras · Mathematics 2019-03-20 Vrej Zarikian

We introduce a real-parameter refinement of the classical integer hierarchies underlying Schmidt number, block-positivity, and $k$-positivity for maps between matrix algebras. Starting from a compact family of $\alpha$-admissible unit…

Functional Analysis · Mathematics 2026-02-16 Mohsen Kian

An extension $K/k$ of analytic (i.e. real valued complete) fields is called small if it is topologically-algebraically generated by finitely many elements. We prove that this property is inherited by subextensions and hence topological…

Algebraic Geometry · Mathematics 2025-11-04 Michael Temkin

We study pairs (C,D) of unital C*-algebras where D is a regular abelian C*-subalgebra of C. When D is a MASA in C, we prove the existence and uniqueness of a completely positive unital map E of C into the injective envelope I(D) of D whose…

Operator Algebras · Mathematics 2012-04-10 David R. Pitts

Let $W_+$ be the positive Witt algebra, which has a $C$-basis $\{e_n: n \in Z_{\geq 1}\}$, with Lie bracket $[ e_i, e_j] = (j-i) e_{i+j}$. We study the two-sided ideal structure of the universal enveloping algebra $U(W_+)$ of $W_+$. We show…

Rings and Algebras · Mathematics 2019-05-16 Alexey V. Petukhov , Susan J. Sierra

We introduce diagonal comparison, a regularity property of diagonal pairs where the sub-C*-algebra has totally disconnected spectrum, and establish its equivalence with the concurrence of strict comparison of the ambient C*-algebra and…

Operator Algebras · Mathematics 2025-04-18 Grigoris Kopsacheilis , Wilhelm Winter

We study conditional expectations generated by an abelian $ C^* $-subalgebra in the centralizer of a positive functional. We formulate and prove Jensen's inequality for functions of several variables with respect to this type of conditional…

Operator Algebras · Mathematics 2007-05-23 Frank Hansen

Some systems of nonlinear wave equations admit global solutions for all sufficiently small initial data, while others do not. The (classical) null condition guarantees that such a result holds, but it is too strong to capture certain…

Analysis of PDEs · Mathematics 2019-06-06 Joseph Keir

In this paper, we consider pure infiniteness of generalized Cuntz-Krieger algebras associated to labeled spaces $(E,\mathcal{L},\mathcal{E})$. It is shown that a $C^*$-algebra $C^*(E,\mathcal{L},\mathcal{E})$ is purely infinite in the sense…

Operator Algebras · Mathematics 2017-03-07 Ja A Jeong , Eun Ji Kang , Gi Hyun Park

Kadison--Schwarz (KS) maps form a natural class of positive linear maps lying strictly between positivity and complete positivity. Despite their relevance in operator algebras and quantum dynamics, explicit analytic sufficient conditions…

Quantum Physics · Physics 2026-03-04 Adam Rutkowski

It seems that the index theory for non-compact spaces has found its ultimate formulation in realm of coarse spaces and $K$-theory of related operator algebras. Relative and partitioned index theorems may be mentioned as two important and…

K-Theory and Homology · Mathematics 2018-04-03 Moin Karami , Mostafa E. Zadeh , Ahmad H. S. Sadegh
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