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Related papers: Fell bundle ladder

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Given a free and proper action of a groupoid on a Fell bundle (over another groupoid), we give an equivalence between the semidirect-product and the generalized-fixed-point Fell bundles, generalizing an earlier result where the action was…

Operator Algebras · Mathematics 2021-12-30 Lucas Hall , S. Kaliszewski , John Quigg , Dana P. Williams

We introduce the concept of a higher algebroid, generalizing the notions of an algebroid and a higher tangent bundle. Our ideas are based on a description of (Lie) algebroids as vector bundle comorphisms - differential relations of a…

Differential Geometry · Mathematics 2019-01-01 Michał Jóźwikowski , Mikołaj Rotkiewicz

We introduce the notion of self-similar actions of grouopids on other groupoids and Fell bundles. This leads to a new imprimitivity theorem arising from such dynamics, generalizing many earlier imprimitivity theorems involving group and…

Operator Algebras · Mathematics 2023-10-05 Anna Duwenig , Boyu Li

We construct an Ulrich bundle on the blowup at a point when the original variety is embedded by a sufficiently positive linear system and carries an Ulrich bundle. In particular, we describe the relation between special Ulrich bundles on…

Algebraic Geometry · Mathematics 2016-07-12 Yeongrak Kim

We study different notions of slope of a vector bundle over a smooth projective curve with respect to ampleness and affineness in order to apply this to tight closure problems. This method gives new degree estimates from above and from…

Algebraic Geometry · Mathematics 2007-05-23 Holger Brenner

We introduce notions of linear reduction and linear equivalence of bijections for the purposes of study bijections between Young tableaux. Originating in Theoretical Computer Science, these notions allow us to give a unified view of a…

Combinatorics · Mathematics 2007-05-23 Igor Pak , Ernesto Vallejo

Given a pair of number fields with isomorphic rings of adeles, we construct bijections between objects associated to the pair. For instance we construct an isomorphism of Brauer groups that commutes with restriction. We additionally…

Group Theory · Mathematics 2018-11-14 Benjamin Linowitz , D. B. McReynolds , Nicholas Miller

We discuss natural connections between three objects: quadratic forms with values in line bundles, conic bundles and quaternion orders. We use the even Clifford algebra, and the Brauer-Severi Variety, and other constructions to give natural…

Rings and Algebras · Mathematics 2011-01-11 Daniel Chan , Colin Ingalls

In this paper we give an algorithm to determine, for any given suborder closed class of series-parallel posets, a structure theorem for the class. We refer to these structure theorems as structural descriptions.

Combinatorics · Mathematics 2011-10-18 Christian Joseph Altomare

In this paper we study deformations of $C^*$-algebras that are given as cross-sectional $C^*$-algebras of Fell bundles over locally compact groups $G$. Our deformation comes from a direct deformation of the Fell bundles via certain…

Operator Algebras · Mathematics 2026-01-14 Alcides Buss , Siegfried Echterhoff

Given a continuous open surjective morphism $\pi :G\to H$ of \'etale groupoids with amenable kernel, we construct a Fell bundle $E$ over $H$ and prove that its C*-algebra $C^*_r(E)$ is isomorphic to $C^*_r(G)$. This is related to results of…

Operator Algebras · Mathematics 2007-07-14 Valentin Deaconu , Alex Kumjian , Birant Ramazan

We review the concept of a graded bundle as a natural generalisation of a vector bundle. Such geometries are particularly nice examples of more general graded manifolds. With hindsight there are many examples of graded bundles that appear…

Differential Geometry · Mathematics 2016-05-12 Andrew J. Bruce , K. Grabowska , J. Grabowski

Given a unital AF-algebra $A$ equipped with a faithful tracial state, we equip each (norm-closed two-sided) ideal of $A$ with a metrized quantum vector bundle structure, when canonically viewed as a module over $A$, in the sense of…

Operator Algebras · Mathematics 2022-11-22 Konrad Aguilar , Jiahui Yu

We consider when a smooth vector bundle endowed with a connection possesses non-trivial, local parallel sections. This is accomplished by means of a derived flag of subsets of the bundle. The procedure is algebraic and rests upon the…

Differential Geometry · Mathematics 2008-04-11 Richard Atkins

The ability to compare complex systems can provide new insight into the fundamental nature of the processes captured in ways that are otherwise inaccessible to observation. Here, we introduce the $n$-tangle method to directly compare two…

Physics and Society · Physics 2014-11-27 Lazaros K. Gallos , Nina H. Fefferman

In this paper we construct the notions of double Fell bundle and double C*-category for possible future use as tools to describe noncommutative spaces, in particular in finite dimensions. We identify the algebra of sections of a double Fell…

Mathematical Physics · Physics 2013-04-18 Rachel A. D. Martins

We study vector bundles on curves with rational tails and their smoothings and give a sufficient condition for the general fibre to be balanced.

Algebraic Geometry · Mathematics 2022-11-22 Ziv Ran

We prove a version of Wordingham's theorem for left regular representations in the setting of Fell bundles of inverse semigroups and use this result to discuss the various associated cross sectional C*-algebras.

Operator Algebras · Mathematics 2016-11-11 Erik Bédos , Magnus D. Norling

This paper gives various methods for constructing vector bundles over elliptic curves and more generally over families of elliptic curves. We construct universal families over generalized elliptic curves via spectral cover methods and also…

alg-geom · Mathematics 2008-02-03 Robert Friedman , John W. Morgan , Edward Witten

We describe a method for predicting a classification of an object given classifications of the objects in the training set, assuming that the pairs object/classification are generated by an i.i.d. process from a continuous probability…

Machine Learning · Computer Science 2013-02-01 Alex Gammerman , Volodya Vovk , Vladimir Vapnik