Now showing items 1-19 of 19

• #### Positive Margins and Primary Decomposition ﻿

[OWP-2012-06] (Mathematisches Forschungsinstitut Oberwolfach, 2012)
We study random walks on contingency tables with fixed marginals, corresponding to a (log-linear) hierarchical model. If the set of allowed moves is not a Markov basis, then there exist tables with the same marginals that ...
• #### Strongly Consistent Density Estimation of Regression Redidual ﻿

[OWP-2012-07] (Mathematisches Forschungsinstitut Oberwolfach, 2012)
Consider the regression problem with a response variable $Y$ and with a $d$-dimensional feature vector $X$. For the regression function $m(x) = \mathbb{E}\{Y|X = x\}$, this paper investigates methods for estimating the ...
• #### Rate of Convergence of the Density Estimation of Regression Residual ﻿

[OWP-2012-08] (Mathematisches Forschungsinstitut Oberwolfach, 2012)
Consider the regression problem with a response variable $Y$ and with a $d$-dimensional feature vector $X$. For the regression function $m(x) = \mathbb{E}\{Y|X = x\}$, this paper investigates methods for estimating the ...
• #### Contractive Idempotents on Locally Compact Quantum Groups ﻿

[OWP-2012-19] (Mathematisches Forschungsinstitut Oberwolfach, 2012)
A general form of contractive idempotent functionals on coamenable locally compact quantum groups is obtained, generalising the result of Greenleaf on contractive measures on locally compact groups. The image of a convolution ...
• #### A Uniform Model for Kirillov-Reshetikhin Crystals I: Lifting the Parabolic Quantum Bruhat Graph ﻿

[OWP-2012-18] (Mathematisches Forschungsinstitut Oberwolfach, 2012)
We consider two lifts of the parabolic quantum Bruhat graph, one into the Bruhat order in the affine Weyl group and the other into a level-zero weight poset first considered by Littelmann. The lift into the affine Weyl ...
• #### On the autonomous metric on the group of area-preserving diffeomorphisms of the 2-disc ﻿

[OWP-2012-16] (Mathematisches Forschungsinstitut Oberwolfach, 2012)
Let $D^2$ be the open unit disc in the Euclidean plane and let $G := Diff(D^2; area)$ be the group of smooth compactly supported area-preserving diffeomorphisms of $D^2$. For every natural number $k$ we construct an injective ...
• #### Invariants of Closed Braids via Counting Surfaces ﻿

[OWP-2012-15] (Mathematisches Forschungsinstitut Oberwolfach, 2012)
A Gauss diagram is a simple, combinatorial way to present a link. It is known that any Vassiliev invariant may be obtained from a Gauss diagram formula that involves counting subdiagrams of certain combinatorial types. In ...
• #### Commuting Differential Operators and Higher-dimensional Algebraic Varieties ﻿

[OWP-2012-02] (Mathematisches Forschungsinstitut Oberwolfach, 2012-03-20)
Several algebro-geometric properties of commutative rings of partial differential operators as well as several geometric constructions are investigated.
• #### Cryptanalysis of Public-key Cryptosystems Based on Algebraic Geometry Codes ﻿

[OWP-2012-01] (Mathematisches Forschungsinstitut Oberwolfach, 2012-03-20)
This paper addresses the question of retrieving the triple $(\mathcal{X},\mathcal{P},\mathcal{E})$ from the algebraic geometry code $\mathcal{C}_L(\mathcal{X},\mathcal{P},\mathcal{E})$, where $\mathcal{X}$ is an algebraic ...
• #### Invariant Four-forms and Symmetric Pairs ﻿

[OWP-2012-03] (Mathematisches Forschungsinstitut Oberwolfach, 2012-04-24)
We give criteria for real, complex and quaternionic representations to define $s$-representations, focusing on exceptional Lie algebras defined by spin representations. As applications, we obtain the classification of ...
• #### Categoric Aspects of Authentication ﻿

[OWP-2012-05] (Mathematisches Forschungsinstitut Oberwolfach, 2012-04-24)
• #### Weakly Complex Homogeneous Spaces ﻿

[OWP-2012-04] (Mathematisches Forschungsinstitut Oberwolfach, 2012-04-24)
We complete our recent classification of compact inner symmetric spaces with weakly complex tangent bundle by filling up a case which was left open, and extend this classification to the larger category of compact homogeneous ...
• #### Ghost Algebras of Double Burnside Algebras via Schur Functors ﻿

[OWP-2012-09] (Mathematisches Forschungsinstitut Oberwolfach, 2012-07-03)
For a finite group $G$, we introduce a multiplication on the $\mathbb{Q}$-vector space with basis $\mathscr{S}_{G\times G}$, the set of subgroups of ${G \times G}$. The resulting $\mathbb{Q}$-algebra $\tilde{A}$ can be ...
• #### Spatial-Skin Effect for a Spectral Problem with "Slightly Heavy" Concentrated Masses in a Thick Cascade Junction ﻿

[OWP-2012-10] (Mathematisches Forschungsinstitut Oberwolfach, 2012-07-03)
The asymptotic behavior (as $\varepsilon \to 0$) of eigenvalues and eigenfunctions of a boundary- value problem for the Laplace operator in a thick cascade junction with concentrated masses is studied. This cascade junction ...
• #### A real algebra perspective on multivariate tight wavelet frames ﻿

[OWP-2012-11] (Mathematisches Forschungsinstitut Oberwolfach, 2012-08-13)
Recent results from real algebraic geometry and the theory of polynomial optimization are related in a new framework to the existence question of multivariate tight wavelet frames whose generators have at least one vanishing ...
• #### Module Categories for Group Algebras over Commutative Rings ﻿

[OWP-2012-12] (Mathematisches Forschungsinstitut Oberwolfach, 2012-10-01)
We develop a suitable version of the stable module category of a finite group $G$ over an arbitrary commutative ring $k$. The purpose of the construction is to produce a compactly generated triangulated category whose ...
• #### Polynomiality, wall crossings and tropical geometry of rational double hurwitz cycles ﻿

[OWP-2012-13] (Mathematisches Forschungsinstitut Oberwolfach, 2012-12-04)
We study rational double Hurwitz cycles, i.e. loci of marked rational stable curves admitting a map to the projective line with assigned ramification profiles over two fixed branch points. Generalizing the phenomenon ...
• #### On commuting varieties of nilradicals of borel subalgebras of reductive lie algebras ﻿

[OWP-2012-14] (Mathematisches Forschungsinstitut Oberwolfach, 2012-12-04)
Let $G$ be a connected reductive algebraic group defined over an algebraically closed field $\mathbb{k}$ of characteristic zero. We consider the commuting variety $\mathcal{C}(\mathfrak{u})$ of the nilradical $\mathfrak{u}$ ...
• #### K-Triviality, Oberwolfach randomness, and differentiability ﻿

[OWP-2012-17] (Mathematisches Forschungsinstitut Oberwolfach, 2012-12-21)
We show that a Martin-Lof random set for which the effective version of the Lebesgue density theorem fails computes every $K$-trivial set. Combined with a recent result by Day and Miller, this gives a positive solution to ...