English
Related papers

Related papers: Ideals with approximate unit in semicrossed produc…

200 papers

The recently developed theory of partial actions of discrete groups on $C^*$-algebras is extended. A related concept of actions of inverse semigroups on $C^*$-algebras is defined, including covariant representations and crossed products.…

funct-an · Mathematics 2008-02-03 Nandor Sieben

In this paper we derive approximate quasi-interpolants when the values of a function $u$ and of some of its derivatives are prescribed at the points of a uniform grid. As a byproduct of these formulas we obtain very simple approximants…

Numerical Analysis · Mathematics 2008-06-17 Flavia Lanzara , Vladimir Maz'ya , Gunther Schmidt

Full C*-crossed products by actions of locally compact groups are characterized via the existence of suitable maximal coactions, in analogy with Landstad's characterization of reduced crossed products.

Operator Algebras · Mathematics 2007-05-23 S. Kaliszewski , John Quigg

The purpose of this paper is to investigate some properties of fuzzy ideals and fuzzy bi-ideals in gamma-semigroups and to introduce the notion of fuzzy quasi ideals in gamma-semigroups. Here we also characterize a regular gamma-semigroup…

General Mathematics · Mathematics 2011-02-02 Sujit Kumar Sardar , Samit Kumar Majumder , Soumitra Kayal

We survey the extensions of a group by a group using crossed products instead of exact sequences of groups. The approach has various advantages, one of them being that the crossed product is an universal object. Several new applications are…

Group Theory · Mathematics 2014-03-18 A. L. Agore , G. Militaru

The quintuple product identity are deduced from a new semi-finite form, which are obtained from the very-well-poised $_6\phi_5$ series.

Combinatorics · Mathematics 2021-07-27 Jun-Ming Zhu

We investigate one question regarding bicrossed products of finite groups which we believe has the potential of being approachable for other classes of algebraic objects (algebras, Hopf algebras). The problem is to classify the groups that…

Group Theory · Mathematics 2014-03-18 A. L. Agore , A. Chirvasitu , B. Ion , G. Militaru

We characterize factor congruences in semilattices by using generalized notions of order ideal and of direct sum of ideals. When the semilattice has a minimum (maximum) element, these generalized ideals turn into ordinary (dual) ideals.

Logic · Mathematics 2010-11-11 Pedro Sánchez Terraf

We develop a semigroup-theoretic analogue of liaison for relative ideals of a numerical semigroup. Two parallel linkage notions are proposed: a theory based on translates of the semigroup and a theory based on translates of the canonical…

Commutative Algebra · Mathematics 2026-04-17 Ignacio Ojeda

We show that positive elements of a Pedersen ideal of a tensor product can be approximated in a particularly strong sense by sums of tensor products of positive elements. This has a range of applications to the structure of tracial cones…

Operator Algebras · Mathematics 2023-06-28 C. Ivanescu , Dan Kučerovský

The aim of this paper is to study some distinguished classes of $k$-ideals of semirings, which include $k$-prime, $k$-semiprime, $k$-radical, $k$-irreducible, and $k$-strongly irreducible ideals. We discuss some of the properties of…

Rings and Algebras · Mathematics 2023-04-11 Themba Dube , Amartya Goswami

In the present paper, we give a full description of the jet schemes of the polynomial ideal $\left( x_1\ldots x_n \right) \in k[x_1, \ldots, x_n]$ over a field of zero characteristic. We use this description to answer questions about…

Commutative Algebra · Mathematics 2018-12-04 Gleb Pogudin

Using the idea of quasi-ideals of $P$-regular nearrings, the concept of bi-ideals of $P$-regular nearrings is generalized, which is an extension of the concept of quasi-ideals of $P$-regular nearrings and some interesting characterizations…

Rings and Algebras · Mathematics 2012-12-18 Aphisit Muangma , Aiyared Iampan

In this paper we give a construction for a linear quotient ordering of a class of products of two ideals which have linear quotients. We apply this construction to give a class of modified anticycle graphs whose square and cube have linear…

Commutative Algebra · Mathematics 2026-03-05 Stephen Landsittel

This paper considers numerical semigroups $S$ that have a non-principal relative ideal $I$ such that $\mu_S(I)\mu_S(S-I)=\mu_S(I+(S-I)) $. We show the existence of an infinite family of such which $I+(S-I)=S\backslash\{0\}$. We also show…

Commutative Algebra · Mathematics 2007-05-23 Kurt Herzinger , Stephen Wilson , Nándor Sieben , Jeff Rushall

In this paper, we define and study quasi S-primary hyperideals, weakly quasi S-hyperideals and strongly S-primary hyperideals.

Commutative Algebra · Mathematics 2025-06-17 Mahdi Anbarloei

The paper presents a construction of the crossed product of a C*-algebra by a semigroup of endomorphisms generated by partial isometries.

Operator Algebras · Mathematics 2014-11-27 B. K. Kwasniewski , A. V. Lebedev

Morita equivalence of twisted inverse semigroup actions and discrete twisted partial actions are introduced. Morita equivalent actions have Morita equivalent crossed products.

Operator Algebras · Mathematics 2010-10-05 Nandor Sieben

An ideal on a set $X$ is a collection of subsets of $X$ closed under the operations of taking finite unions and subsets of its elements. Ideals are a very useful notion in topology and set theory and have been studied for a long time. We…

Logic · Mathematics 2019-02-26 Carlos Uzcategui

Starting from an arbitrary endomorphism \delta of a unital C*-algebra A we construct a crossed product. It is shown that the natural construction depends not only on the C*-dynamical system (A,\delta) but also on the choice of an ideal J…

Operator Algebras · Mathematics 2007-05-23 B. K. Kwasniewski , A. V. Lebedev