We show that elements of unital C-algebras without tracial states are finite sums of commutators. Moreover, the number of commutators involved is bounded, depending only on the given C-algebra.

Suppose M is a von Neumann algebra with normal, tracial state ϕ and {a 1 ,. .. , a n } is a set of self-adjoint elements of M. We provide an alternative uniform packing description of δ 0

Let X be a compact metric space and let α be a homeomorphism on X. Related to a theorem of Pimsner, we show that C(X) ⋊α Z can be embedded into a unital simple AF-algebra if and only if there is a strictly positive α-invariant Borel probability measure. Suppose that Λ is a Z action on X. If C(X)⋊Λ Z can be embedded into a unital simple AF-algebra, then there must exist a strictly positive Λ-inv...

Let C be a unital AH-algebra and let A be a unital separable simple C-algebra with tracial rank no more than one. Suppose that φ, ψ : C → A are two unital monomorphisms. With some restriction on C, we show that φ and ψ are approximately unitarily equivalent if and only if [φ] = [ψ] in KL(C,A) τ ◦ φ = τ ◦ ψ for all tracial states of A and φ = ψ, where φ and ψ are homomorphisms from U0(C)/CU(C) →...

The paper tells about the main features and events of ergodic seminar organized headed by V. A. Rokhlin at Leningrad State University. was active in 1960–1970.

Boundary integral equations and Nyström discretization provide a powerful tool for the solution of Laplace and Helmholtz boundary value problems. However, often a weaklysingular kernel arises, in which case specialized quadratures that modify the matrix entries near the diagonal are needed to reach a high accuracy. We describe the construction of four different quadratures which handle logarith...

We prove the title, establishing the existence of a quasitrace on a (unital, simple) C-algebra (of real rank zero and stable rank one), which is not a tracial state.