The Regular C * - algebra of an Integral Domain Joachim Cuntz

Classification of sectors of the Cuntz algebras by graph invariants

A unitary equivalence class of endomorphisms of a unital C∗-algebra A is called a sector of A. We introduced permutative endomorphisms of the Cuntz algebra ON in the previous work. Branching laws of permutative representations of ON by them are computed by directed regular graphs. In this article, we classify sectors associated with permutative endomorphisms of ON by their graph invariants conc...

Existence of an Algebra Norm on Certain Subalgebras of C(X)

Arens regularity and derivations of Hilbert modules with the certain product

Let $A$ be a $C^*$-algebra and $E$ be a left Hilbert $A$-module. In this paper we define a product on $E$ that making it into a Banach algebra and show that under the certain conditions $E$  is Arens regular. We also study the relationship between derivations of $A$ and $E$.

Exactness of Cuntz–pimsner C–algebras

Let H be a full Hilbert bimodule over a C-algebra A. We show that the Cuntz–Pimsner algebra associated to H is exact if and only if A is exact. Using this result, we give alternative proofs for exactness of reduced amalgemated free products of exact C– algebras. In the case that A is a finite–dimensional C–algebra, we also show that the Brown–Voiculescu topological entropy of Bogljubov automorp...

Numerical solution of Fredholm integral-differential equations on unbounded domain

In this study, a new and efficient approach is presented for numerical solution of Fredholm integro-differential equations (FIDEs) of the second kind on unbounded domain with degenerate kernel based on operational matrices with respect to generalized Laguerre polynomials(GLPs). Properties of these polynomials and operational matrices of integration, differentiation are introduced and are ultili...