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Related papers: Ghostly ideals in uniform Roe algebras

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We study (two-sided) ideals $I$ in the enveloping algebra $\U(\frak g_\infty)$ of an infinite-dimensional Lie algebra $\frak g_\infty$ obtained as the union (equivalently, direct limit) of an arbitrary chain of embeddings of simple…

Algebraic Geometry · Mathematics 2012-10-02 Ivan Penkov , Alexey Petukhov

The structure of the complex $\operatorname{\mathbf{R}Hom}_R(R/I,R)$ is explored for an Ulrich ideal $I$ in a Cohen-Macaulay local ring $R$. As a consequence, it is proved that in a one-dimensional almost Gorenstein but non-Gorenstein local…

Commutative Algebra · Mathematics 2016-05-17 Shiro Goto , Ryo Takahashi , Naoki Taniguchi

A ghost over a finite p-group G is a map between modular representations of G which is invisible in Tate cohomology. Motivated by the failure of the generating hypothesis---the statement that ghosts between finite-dimensional…

Representation Theory · Mathematics 2011-12-26 Sunil K. Chebolu , J. Daniel Christensen , Jan Minac

In this paper, we study embeddings of uniform Roe algebras. Generally speaking, given metric spaces $X$ and $Y$, we are interested in which large scale geometric properties are stable under embedding of the uniform Roe algebra of $X$ into…

Operator Algebras · Mathematics 2019-06-28 Bruno de Mendonça Braga , Ilijas Farah , Alessandro Vignati

Inner ideals of simple locally finite dimensional Lie algebras over an algebraically closed field of characteristic 0 are described. In particular, it is shown that a simple locally finite dimensional Lie algebra has a non-zero proper inner…

Representation Theory · Mathematics 2013-01-29 Alexander Baranov , Jamie Rowley

Let $R$ be a ring with unity. The upper ideal relation graph $\Gamma_U(R)$ of the ring $R$ is a simple undirected graph whose vertex set is the set of all non-unit elements of $R$ and two distinct vertices $x, y$ are adjacent if and only if…

Rings and Algebras · Mathematics 2024-03-08 Barkha Baloda , Jitender Kumar

A notion of partial ideal for an operator algebra is a weakening the notion of ideal where the defining algebraic conditions are enforced only in the commutative subalgebras. We show that, in a von Neumann algebra, the ultraweakly closed…

Operator Algebras · Mathematics 2014-08-07 Nadish de Silva , Rui Soares Barbosa

An inspection of the precise geometric constructions underlying fundamental notions in quantum gauge field theories sheds light on various aspects which tend to be obscured in the usual formalisms. Revising the notions of mutually…

Mathematical Physics · Physics 2016-12-21 Daniel Canarutto

In this paper, using the concept of ideal, we study the idea of rough ideal convergence of sequences which is an extension of the notion of rough convergence of sequences in a partial metric space. We define the set of rough…

General Topology · Mathematics 2025-01-15 Sukila Khatun , Amar Kumar Banerjee , Rahul Mondal

An ideal is a nonempty collection of subsets closed under heredity and finite additivity. The aim of this paper is to unify some weak separation properties via topological ideals. We concentrate our attention on the separation axioms…

General Topology · Mathematics 2007-05-23 Francisco G. Arenas , Julian Dontchev , Maria Luz Puertas

The study of different types of ideals in non self-adjoint operator algebras has been a topic of recent research. This study focuses on principal ideals in subalgebras of groupoid C*-algebras. An ideal is said to be principal if it is…

Operator Algebras · Mathematics 2007-05-23 Srilal Krishnan

We prove that uniformly locally finite metric spaces with isomorphic Roe algebras must be coarsely equivalent. As an application, we also prove that the outer automorphism group of the Roe algebra of a metric space of bounded geometry is…

Operator Algebras · Mathematics 2025-03-10 Diego Martínez , Federico Vigolo

Roe algebras are C*-algebras built using large-scale (or 'coarse') aspects of a metric space (X,d). In the special case that X=G is a finitely generated group and d is a word metric, the simplest Roe algebra associated to (G,d) is…

Operator Algebras · Mathematics 2013-09-24 Jan Spakula , Rufus Willett

Geometric algebra is an optimal frame work for calculating with vectors. The geometric algebra of a space includes elements that represent all the its subspaces (lines, planes, volumes, ...). Conformal geometric algebra expands this…

Computer Vision and Pattern Recognition · Computer Science 2013-06-07 Eckhard Hitzer

In this paper, we study the relation between the uniform Roe algebra and the uniform quasi-local algebra associated to a metric space of bounded geometry. In the process, we introduce a weakening of the notion of expanders, called…

Operator Algebras · Mathematics 2020-04-02 Kang Li , Piotr Nowak , Ján Špakula , Jiawen Zhang

Let $\mathscr{A}$ be a finite set of closed rational points in projective space, let $\mathscr{I}$ be the vanishing ideal of $\mathscr{A}$, and let $\mathscr{D}(\mathscr{A})$ be the set of exponents of those monomials which do not occur as…

Commutative Algebra · Mathematics 2007-11-19 Mathias Lederer

We define the concept of a partial translation structure T on a metric space X and we show that there is a natural C*-algebra C*(T) associated with it which is a subalgebra of the uniform Roe algebra C*_u(X). We introduce a coarse invariant…

Operator Algebras · Mathematics 2007-05-23 J. Brodzki , G. A. Niblo , N. J. Wright

With each Fell bundle over a discrete group G we associate a partial action of G on the spectrum of the unit fiber. We discuss the ideal structure of the corresponding full and reduced cross-sectional C*-algebras in terms of the dynamics of…

Operator Algebras · Mathematics 2015-04-23 Beatriz Abadie , Fernando Abadie

We define weighted projective Reed-Muller codes over a subset of weighted projective space over a finite field. We focus on the case when the set X is a projective weighted torus. We show that the vanishing ideal of X is a lattice ideal and…

Commutative Algebra · Mathematics 2013-07-25 Eduardo Dias , Jorge Neves

In this paper we investigate the Rees algebras of squarefree monomial ideals $I \subset S=K[x_1,\dots,x_n]$ generated in degree $n-2$, where $K$ is a field. Every such ideal arises as the complementary edge ideal $I_c(G)$ of a finite simple…

Commutative Algebra · Mathematics 2025-09-24 Antonino Ficarra , Somayeh Moradi