English
Related papers

Related papers: Crossed Products and Coding Theory

200 papers

A code $C$ in the Hamming metric, that is, is a subset of the vertex set $V\varGamma$ of the Hamming graph $\varGamma=H(m,q)$, gives rise to a natural distance partition $\{C,C_1,\ldots,C_\rho\}$, where $\rho$ is the covering radius of $C$.…

Combinatorics · Mathematics 2022-08-02 Robert F. Bailey , Daniel R. Hawtin

We study the C*-algebra crossed product $C_0(X)\rtimes G$ of a locally compact group $G$ acting properly on a locally compact Hausdorff space $X$. Under some mild extra conditions, which are automatic if $G$ is discrete or a Lie group, we…

K-Theory and Homology · Mathematics 2010-12-24 Heath Emerson , Siegfried Echterhoff

We generalize the notion of a crossed module of groups to that of a crossed module of racks. We investigate the relation to categorified racks, namely strict 2-racks, and trunk-like objects in the category of racks, generalizing the…

Quantum Algebra · Mathematics 2014-04-02 Alissa S. Crans , Friedrich Wagemann

Let $\Gamma^+$ be the positive cone in a totally ordered abelian group $\Gamma$, and let $\alpha$ be an action of $\Gamma^+$ by endomorphisms of a $C^*$-algebra $A$. We consider a new kind of crossed-product $C^*$-algebra…

Operator Algebras · Mathematics 2007-05-23 Janny Lindiarni , Iain Raeburn

For a linear Hamming metric code of length n over a finite field, the number of distinct weights of its codewords is at most n. The codes achieving the equality in the above bound were called full weight spectrum codes. In this paper we…

Information Theory · Computer Science 2024-05-31 Chiara Castello , Olga Polverino , Ferdinando Zullo

Let $X_0, X_1, ..., X_k$ with $k \in \IN\cup\{\infty\}$ be sequence spaces $($finite or infinite dimensional$)$ over $\IC$ or $\IR$ with absolute norms $N_i$ for $i = 0, ..., k$, $($i.e., with 1-unconditional bases$)$ such that $\dim X_0 =…

Functional Analysis · Mathematics 2009-09-25 Chi-Kwong Li , Beata Randrianantoanina

Given two associative algebras A, C and a linear space V together with some linear maps R_1, R_2, R_3, E satisfying some conditions, we define an associative algebra structure on A\otimes V\otimes C called a two-sided crossed product.…

Quantum Algebra · Mathematics 2024-10-22 Florin Panaite

Using the computational approach introduced in [Agore A.L., Bontea C.G., Militaru G., J. Algebra Appl. 12 (2013), 1250227, 24 pages, arXiv:1207.0411] we classify all coalgebra split extensions of $H_4$ by $k[C_n]$, where $C_n$ is the cyclic…

Rings and Algebras · Mathematics 2014-04-24 Ana-Loredana Agore , Costel-Gabriel Bontea , Gigel Militaru

In this paper we introduce and investigate rank-metric intersecting codes, a new class of linear codes in the rank-metric context, inspired by the well-studied notion of intersecting codes in the Hamming metric. A rank-metric code is said…

Combinatorics · Mathematics 2025-07-02 Daniele Bartoli , Martino Borello , Giuseppe Marino , Martin Scotti

We construct the crossed product of a C(X)-algebra by an endomorphism, in such a way that the endomorphism itself becomes induced by the bimodule of continuous sections of a vector bundle. Some motivating examples for such a construction…

Operator Algebras · Mathematics 2011-11-21 Ezio Vasselli

We show how to equip the crossed product between a group of polynomial growth and a compact quantum metric space with a compact quantum metric space structure. When the quantum metric on the base space arises from a spectral triple, which…

Operator Algebras · Mathematics 2024-12-02 Are Austad , Jens Kaad , David Kyed

Cyclomatic complexity is an incompletely specified but mathematically principled software metric that can be usefully applied to both source and binary code. We consider the application of path homology as a stronger analogue of cyclomatic…

Software Engineering · Computer Science 2020-08-28 Steve Huntsman

The $r$-th generalized Hamming metric and the $b$-symbol metric are two different generalizations of Hamming metric. The former is used on the wire-tap channel of Type II, and the latter is motivated by the limitations of the reading…

Cryptography and Security · Computer Science 2021-09-29 Minjia Shi , Hongwei Zhu , Tor Helleseth

The category of crossed complexes gives an algebraic model of the category of $CW$-complexes and cellular maps. We explain basic results on crossed complexes which allow the computation of free crossed resolutions of graph products of…

Algebraic Topology · Mathematics 2007-05-23 Ronald Brown , Manuel Bullejos , Timothy Porter

This article examines group ring codes over finite fields and finite groups. We also present a section on two-dimensional cyclic codes in the quotient ring $\mathbb{F}_q[x, y] / \langle x^{l} - 1, y^{m} - 1 \rangle$. These two-dimensional…

Information Theory · Computer Science 2025-04-22 Kanat Abdukhalikov , Tushar Bag , Daniel Panario

We decompose the crossed product functor for actions of crossed modules of locally compact groups on C*-algebras into more elementary constructions: taking crossed products by group actions and fibres in C*-algebras over topological spaces.…

Operator Algebras · Mathematics 2015-06-02 Alcides Buss , Ralf Meyer

Skew polynomial rings over finite fields ([7] and [10]) and over Galois rings ([8]) have been used to study codes. In this paper, we extend this concept to finite chain rings. Properties of skew constacyclic codes generated by monic right…

Information Theory · Computer Science 2010-10-04 Somphong Jitman , San Ling , Patanee Udomkavanich

The equivariant cohomology for actions of compact connected abelian groups and elementary abelian p-groups have been widely studied in the last decades. We study some of these results on actions of finite cyclic groups over a field of…

Algebraic Topology · Mathematics 2022-06-24 Sergio Chaves

All crossed products of two cyclic groups are explicitly described using generators and relations. A necessary and sufficient condition for an extension of a group by a group to be a cyclic group is given.

Group Theory · Mathematics 2014-02-24 Ana-Loredana Agore , Dragos Fratila

A product system E over a semigroup P is a family of Hilbert spaces {E_s:s\in P} together with multiplications E_s \times E_t\to E_{st}. We view E as a unitary- valued cocycle on P, and consider twisted crossed products A \times_{\beta,E} P…

funct-an · Mathematics 2008-02-03 N. Fowler , I. Raeburn