English
Related papers

Related papers: Projections in Graph W*-Algebras

200 papers

Building on recent work of Robertson and Steger, we associate a C*-algebra to a combinatorial object which may be thought of as a higher rank graph. This C*-algebra is shown to be isomorphic to that of the associated path groupoid.…

Operator Algebras · Mathematics 2007-05-23 Alex Kumjian , David Pask

A unified description of the relationship between the Hamiltonian structure of a large class of integrable hierarchies of equations and W-algebras is discussed. The main result is an explicit formula showing that the former can be…

High Energy Physics - Theory · Physics 2007-05-23 C. R. Fernández-Pousa , M. V. Gallas , J. L. Miramontes , J. Sánchez Guillén

This work studies certain aspects of graphs embedded on surfaces. Initially, a colored graph model for a map of a graph on a surface is developed. Then, a concept analogous to (and extending) planar graph is introduced in the same spirit as…

Combinatorics · Mathematics 2007-05-23 Sostenes Lins

We initiate the study of pointed approximative absolute neighborhood retracts. Our motivation is to generate examples of C*-algebras that behave in unexpected ways with respect to weak semiprojectivity. We consider both weak…

Operator Algebras · Mathematics 2014-01-16 Terry A. Loring

We discuss various phenomena of tangency in projective and convex geometry.

Algebraic Geometry · Mathematics 2011-03-07 Roland Abuaf

This note is on the structures of line graphs and 2-variegated graphs. We have given here solutions of some graph equations involving line graphs and 2-variegated graphs.

Combinatorics · Mathematics 2025-08-08 Ranjan N. Naik

An action of Z^l by automorphisms of a k-graph induces an action of Z^l by automorphisms of the corresponding k-graph C*-algebra. We show how to construct a (k+l)-graph whose C*-algebra coincides with the crossed product of the original…

Operator Algebras · Mathematics 2007-06-26 Cynthia Farthing , David Pask , Aidan Sims

This survey reports on current progress of programs to classify graph C*-algebras and Leavitt path algebras up to Morita equivalence using K-theory. Beginning with an overview and some history, we trace the development of the classification…

Operator Algebras · Mathematics 2016-03-22 Mark Tomforde

Some notions of algebraic geometry can be defined for arbitrary varieties of algebras. This leads to universal algebraic geometry. The main idea of the presented theory is to consider interactions between algebra, logic and geometry in…

General Mathematics · Mathematics 2007-05-23 Boris Plotkin

We use non-symmetric distances to give a self-contained account of C*-algebra filters and their corresponding compact projections, simultaneously simplifying and extending their general theory.

Operator Algebras · Mathematics 2019-11-19 Tristan Bice , Alessandro Vignati

We show that semiprojectivity of a C*-algebra is preserved when passing to C*-subalgebras of finite codimension. In particular, any pullback of two semiprojective C*-algebras over a finite-dimensional C*-algebra is again semiprojective.

Operator Algebras · Mathematics 2014-05-13 Dominic Enders

This dissertation concerns the classification of groupoid and higher-rank graph C*-algebras and has two main components. Firstly, for a groupoid it is shown that the notions of strength of convergence in the orbit space and…

Operator Algebras · Mathematics 2013-05-28 Robert Hazlewood

In this study, after introducing algebraic properties of real quaternions some characterizations of quaternionic involute-evolute curves in Q are obtained. And some results and theorems for quaternionic w-curves are given. Lastly, we…

Geometric Topology · Mathematics 2013-11-05 Tülay Soyfidan , Mehmet Ali Güngör

We develop a theory of toroidal vertex algebras and their modules, and we give a conceptual construction of toroidal vertex algebras and their modules. As an application, we associate toroidal vertex algebras and their modules to toroidal…

Quantum Algebra · Mathematics 2012-01-30 Haisheng Li , Shaobin Tan , Qing Wang

We introduce a method to define $C^*$-algebras from $C^*$-correspondences. Our construction generalizes Cuntz-Pimsner algebras, crossed products by Hilbert $C^*$-modules, and graph algebras.

Operator Algebras · Mathematics 2007-05-23 Takeshi Katsura

We suggest two explicit descriptions of the Poisson q-W algebras which are Poisson algebras of regular functions on certain algebraic group analogues of the Slodowy transversal slices to adjoint orbits in a complex semisimple Lie algebra g.…

Quantum Algebra · Mathematics 2017-09-20 A. Sevostyanov

In this (mostly) survey article, we give a synopsis of a number of results relating to Brill--Noether theory on curves and metric graphs, together with some speculations about the behavior of one-dimensional linear series on a class of…

Algebraic Geometry · Mathematics 2013-03-20 Ethan Cotterill

An elegant description of the general form of order automorphisms of effect algebras has been known in the complex case. We present a much simpler proof based on the projective geometry which works also in the real case. As an application…

Functional Analysis · Mathematics 2026-02-25 Peter Semrl

We obtain a complete classification of minimal simple unitary $W$-algebras.

Representation Theory · Mathematics 2024-08-05 Victor G. Kac , Pierluigi Möseneder Frajria , Paolo Papi

The arrow graph of a function consists of two parallel axes, with arrows from input values to output values. The lines through these arrows envelop a curve which we named the focal curve. This paper studies these focal curves in detail. We…

History and Overview · Mathematics 2025-11-26 Rogier Bos , Filip Cools