There are two notions of amenability for discrete equivalence relations. The \global" amenability (which is usually referred to just as \amenability") is the property of existence of leafwise invariant means, which, by a theorem of Connes{Feldman{Weiss, is equivalent to hyperrniteness, or, to being the orbit equivalence relation of a Z-action. The notion of \local" amenability applies to equiva...

Let A be a Banach algebra and X a Banach A-bimodule, the derivation D : A → X is semi-inner if there are ξ, μ ∈ X such that D(a) = a.ξ − μ.a, (a ∈ A). A is called semi-amenable if every derivation D : A → X∗ is semi-inner. The dual Banach algebra A is Connes semi-amenable (resp. approximately semi-amenable) if, every D ∈ Z1w _ (A,X), for each normal, dual Banach A-bimodule X, is semi -inner (re...

Abstract We construct two types of unital separable simple $C^*$ -algebras: $A_z^{C_1}$ and $A_z^{C_2}$ , one exact but not amenable, the other nonexact. Both have same Elliott invariant as Jiang–Su algebra – namely, $A_z^{C_i}$ has a unique tracial state, $$ \begin{align*} \left(K_0\left(A_z^{C_i}\right), K_0\left(A_z^{C_i}\right)_+, \left[1_{A_z^{C_i}} \right]\right)=(\mathbb{Z}, \mathbb{Z}_+...

The notion of amenability was introduced in 1929 by J. von Neumann [68] in order to explain the Banach-Tarski paradox. A countable discrete group Γ is amenable if there exists a left-invariant mean φ : `∞(Γ) → C. The class of amenable groups is stable under subgroups, direct limits, quotients and the free group F2 on two generators is not amenable. Knowing whether or not the class of amenable g...

Let α : G → G be an endomorphism of a discrete amenable group such that [G : α(G)] < ∞. We study the structure of the C∗ algebra generated by the left convolution operators acting on the left regular representation space, along with the isometry of the space induced by the endomorphism.

This paper summarizes various interpretations of emotional arguments, with a focus on the mode argument introduced in multi-modal argumentation model (Gilbert, 1994). From there author shifts from descriptive account arguments to discussion about normative framework. Pointing out problems evaluative models mode, paradigmatic shift captured by Amenable Argumentation Approach is explained as way ...