Now showing items 20-39 of 337

• #### The Becker-Gottlieb Transfer: a Geometric Description ﻿

[OWP-2019-13] (Mathematisches Forschungsinstitut Oberwolfach, 2019-05-14)
In this note, we examine geometric aspects of the Becker-Gottlieb transfer in terms of the Umkehr and index maps, and rework some classic index theorems, using the cohomological formulae of the Becker-Gottlieb transfer. ...
• #### The Berry-Keating Operator on a Lattice ﻿

[OWP-2016-23] (Mathematisches Forschungsinstitut Oberwolfach, 2016-11-17)
We construct and study a version of the Berry-Keating operator with a built-in truncation of the phase space, which we choose to be a two-dimensional torus. The operator is a Weyl quantisation of the classical Hamiltonian ...
• #### Boundary Representations of Operator Spaces, and Compact Rectangular Matrix Convex Sets ﻿

[OWP-2016-24] (Mathematisches Forschungsinstitut Oberwolfach, 2016-12-13)
We initiate the study of matrix convexity for operator spaces. We define the notion of compact rectangular matrix convex set, and prove the natural analogs of the Krein-Milman and the bipolar theorems in this context. We ...
• #### Braid equivalences and the L-moves ﻿

[OWP-2011-20] (Mathematisches Forschungsinstitut Oberwolfach, 2011-05-19)
In this survey paper we present the L-moves between braids and how they can adapt and serve for establishing and proving braid equivalence theorems for various diagrammatic settings, such as for classical knots, for knots ...
• #### Bredon Cohomology and Robot Motion Planning ﻿

[OWP-2017-34] (Mathematisches Forschungsinstitut Oberwolfach, 2017-11-29)
In this paper we study the topological invariant ${\sf {TC}}(X)$ reflecting the complexity of algorithms for autonomous robot motion. Here, $X$ stands for the configuration space of a system and ${\sf {TC}}(X)$ is, roughly, ...
• #### Calculating conjugacy classes in Sylow p-subgroups of finite Chevalley groups of rank six and seven ﻿

[OWP-2013-10] (Mathematisches Forschungsinstitut Oberwolfach, 2013-04-10)
Let $G(q)$ be a finite Chevalley group, where $q$ is a power of a good prime $p$, and let $U(q)$ be a Sylow $p$-subgroup of $G(q)$. Then a generalized version of a conjecture of Higman asserts that the number $k(U(q))$ of ...
• #### Cataland: Why the Fuß? ﻿

[OWP-2019-01] (Mathematisches Forschungsinstitut Oberwolfach, 2019-01-21)
The three main objects in noncrossing Catalan combinatorics associated to a finite Coxeter system are noncrossing partitions, clusters, and sortable elements. The first two of these have known Fuß-Catalan generalizations. ...
• #### Categoric Aspects of Authentication ﻿

[OWP-2012-05] (Mathematisches Forschungsinstitut Oberwolfach, 2012-04-24)
• #### Categorical Linearly Ordered Structures ﻿

[OWP-2018-08] (Mathematisches Forschungsinstitut Oberwolfach, 2018-04-26)
We prove that for every computable limit ordinal $\alpha$ there exists a computable linear ordering $\mathcal{A}$ which is $\Delta^0_\alpha$-categorical and $\alpha$ is smallest such, but nonetheless for every isomorphic ...
• #### A categorical model for the virtual braid group ﻿

[OWP-2011-19] (Mathematisches Forschungsinstitut Oberwolfach, 2011-05-18)
• #### Central Limit Theorems for the Radial Spanning Tree ﻿

[OWP-2014-18] (Mathematisches Forschungsinstitut Oberwolfach, 2014)
Consider a homogeneous Poisson point process in a compact convex set in d-dimensional Euclidean space which has interior points and contains the origin. The radial spanning tree is constructed by connecting each point of ...
• #### A Characterization of Semisimple Plane Polynomial Automorphisms ﻿

[OWP-2008-08] (Mathematisches Forschungsinstitut Oberwolfach, 2008-03-12)
It is well-known that an element of the linear group $GL_n(\mathbb{C})$ is semisimple if and only if its conjugacy class is Zariski closed. The aim of this paper is to show that the same result holds for the group of complex ...
• #### A Cheeger Type Inequality in Finite Cayley Sum Graphs ﻿

[OWP-2019-21] (Mathematisches Forschungsinstitut Oberwolfach, 2019-07-31) - (5 May - 27 July 2019)
Let $G$ be a finite group and $S$ be a symmetric generating set of $G$ with $|S| = d$. We show that if the undirected Cayley sum graph $C_{\Sigma}(G,S)$ is an expander graph and is non-bipartite, then the spectrum of its ...
• #### Chirality of Real Non-Singular Cubic Fourfolds and Their Pure Deformation Classification ﻿

[OWP-2019-14] (Mathematisches Forschungsinstitut Oberwolfach, 2019-05-15)
In our previous works we have classified real non-singular cubic hypersurfaces in the 5-dimensional projective space up to equivalence that includes both real projective transformations and continuous variations of ...
• #### Classification of idempotent states on the compact quantum groups Uq(2), SUq(2) and SOq(3) ﻿

[OWP-2009-08] (Mathematisches Forschungsinstitut Oberwolfach, 2009-03-02)