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Related papers: On order units in the augmentation ideal

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We introduce a class of Banach algebras of generalized matrices and study the existence of approximate units, ideal structure, and derivations of them.

Functional Analysis · Mathematics 2016-05-16 Maysam Maysami Sadr

We show how to use topological ideas, such as compactness, to establish orderability properties of infinite groups. A new application is to provide a left-ordering for the group of PL homeomorphisms of a connected surface with boundary…

Group Theory · Mathematics 2014-03-20 Dale Rolfsen

Our focus is on the set of lower-triangular, infinite matrices that have natural operations like addition, multiplication by a number, and matrix multiplication. With respect to addition this set forms and abelian group while with respect…

Combinatorics · Mathematics 2026-01-27 Paweł J. Szabłowski

We compute the invariant subspace of the rational group ring of a surface, truncated by powers of the augmentation ideal, under the action of the mapping class group. The surface is compact, oriented with one boundary component. This…

Geometric Topology · Mathematics 2025-10-02 Andreas Stavrou

A characterization of flat ideals in the unit interval with the canonical fuzzy order is obtained with the help of the ordinal sum decomposition of continuous t-norms. This characterization will be useful in the study of topological and…

General Mathematics · Mathematics 2018-01-19 Hongliang Lai , Dexue Zhang , Gao Zhang

The strong isomorphism classes of extensions of finite groups are parametrized by orbits of a prescribed action on the second cohomology group. We study these orbits in the case of extensions of a finite abelian $p$-group by a cyclic factor…

Group Theory · Mathematics 2023-09-25 Oihana Garaialde Ocaña , Mima Stanojkovski

A dimension group is a partially ordered countable group such that (1) every finite subset is contained in an ordered subgroup which is a finite direct power of Z and (2) the group has an order unit i.e. a positive element u such that every…

Group Theory · Mathematics 2007-05-23 Gábor Braun

Ordering theorems, characterizing when partial orders of a group extend to total orders, are used to generate hypersequent calculi for varieties of lattice-ordered groups (l-groups). These calculi are then used to provide new proofs of…

Logic · Mathematics 2017-08-03 Almudena Colacito , George Metcalfe

This article studies the sequence of iterative degrees of a birational map of the plane. This sequence is known either to be bounded or to have a linear, quadratic or exponential growth. The classification elements of infinite order with a…

Algebraic Geometry · Mathematics 2015-09-02 Jérémy Blanc , Julie Déserti

We study the homeomorphism groups of ordinals equipped with their order topology, focusing on successor ordinals whose limit capacity is also a successor. This is a rich family of groups that has connections to both permutation groups and…

Group Theory · Mathematics 2025-08-28 Megha Bhat , Rongdao Chen , Adityo Mamun , Ariana Verbanac , Eric Vergo , Nicholas G. Vlamis

We classify the parabolic unitals in regular nearfield planes of odd order $q^2$ whose linear collineation group has the maximal size of $q^3-q$. We also establish a number of more general results concerning parabolic unitals in regular…

Combinatorics · Mathematics 2026-01-06 Randon J. Weaver , Robert S. Coulter , Alice M. W. Hui

This paper deals with the classification of Leibniz central extensions of a naturally graded filiform Lie algebra. We choose a basis with respect to that the table of multiplication has a simple form. In low dimensional cases isomorphism…

Rings and Algebras · Mathematics 2010-01-12 I. S. Rakhimov , Munther A. Hassan

We consider first-order definability and decidability questions over rings of integers of algebraic extensions of $\Q$, paying attention to the uniformity of definitions. The uniformity follows from the simplicity of our first-order…

Number Theory · Mathematics 2024-06-05 Barry Mazur , Karl Rubin , Alexandra Shlapentokh

We show that the ordered rings naturally associated to compact convex polyhedra with interior satisfy a positivity property known as order unit cancellation, and obtain other general positivity results as well.

Algebraic Geometry · Mathematics 2010-09-30 David Handelman

We study the distances between the unitary orbits of matrix amplifications of elements in certain C*-algebras. In particular, we show that the distance between unitary orbits of arbitrary elements in unital, separable, UHF-stable…

Operator Algebras · Mathematics 2025-08-20 Laurent W. Marcoux , Pawel Sarkowicz , Yuanhang Zhang

Order unit property of a positive element in a $C^{*}$-algebra is defined. It is proved that precisely projections satisfy this order theoretic property. This way, unital hereditary $C^{*}$-subalgebras of a $C^{*}$-algebra are…

Operator Algebras · Mathematics 2007-05-23 Anil K. Karn

This paper investigates atomic factorizations in the monoid $\mathcal I(R)$ of nonzero ideals of a multivariate polynomial ring $R$, under ideal multiplication. Building on recent advances in factorization theory for unit-cancellative…

Commutative Algebra · Mathematics 2026-03-10 Nikola Bogdanovic , Laura Cossu , Azeem Khadam

The matrix units of a digraph algebra, A, induce a relation, known as the diagonal order, on the projections in a masa in the algebra. Normalizing partial isometries in A act on these projections by conjugation; they are said to be order…

funct-an · Mathematics 2016-08-31 Alan Hopenwasser , Allan Donsig

We study the modular representation theory of the symmetric and alternating groups. One of the most natural ways to label the irreducible representations of a given group or algebra in the modular case is to show the unitriangularity of the…

Representation Theory · Mathematics 2020-12-09 Olivier Brunat , Jean-Baptiste Gramain , Nicolas Jacon

H.J. Zassenhaus conjectured that any unit of finite order and augmentation $1$ in the integral group ring $\mathbb{Z}G$ of a finite group $G$ is conjugate in the rational group algebra $\mathbb{Q}G$ to an element of $G$. We prove the…

Group Theory · Mathematics 2018-04-12 Ángel del Río , Mariano Serrano