Browsing by MFO Scientific Program "Research in Pairs 2018"
Now showing items 1-20 of 26
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Affine Space Fibrations
[OWP-2018-19] (Mathematisches Forschungsinstitut Oberwolfach, 2018-09-05)We discuss various aspects of affine space fibrations. Our interest will be focused in the singular fibers, the generic fiber and the propagation of properties of a given smooth special fiber to nearby fibers. -
Applications of BV Type Spaces
[OWP-2019-04] (Mathematisches Forschungsinstitut Oberwolfach, 2019-02-13) -
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. ... -
Categorical Linearly Ordered Structures
[OWP-2018-08] (Mathematisches Forschungsinstitut Oberwolfach, 2018-04-26)We prove that for every computable limit ordinal α there exists a computable linear ordering A which is Δ0α-categorical and α is smallest such, but nonetheless for every isomorphic ... -
Computing Congruence Quotients of Zariski Dense Subgroups
[OWP-2018-22] (Mathematisches Forschungsinstitut Oberwolfach, 2018-10-26)We obtain a computational realization of the strong approximation theorem. That is, we develop algorithms to compute all congruence quotients modulo rational primes of a finitely generated Zariski dense group $H \leq ... -
Criteria for Algebraicity of Analytic Functions
[OWP-2018-25] (Mathematisches Forschungsinstitut Oberwolfach, 2018-11-12)We consider functions defined on an open subset of a nonsingular, either real or complex, algebraic set. We give criteria for an analytic function to be a Nash (resp. regular, resp. polynomial) function. Our criteria depend ... -
Experimenting with Symplectic Hypergeometric Monodromy Groups
[OWP-2019-15] (Mathematisches Forschungsinstitut Oberwolfach, 2019-05-22)We present new computational results for symplectic monodromy groups of hypergeometric differential equations. In particular, we compute the arithmetic closure of each group, sometimes justifying arithmeticity. The results ... -
A Function Algebra Providing New Mergelyan Type Theorems in Several Complex Variables
[OWP-2019-02] (Mathematisches Forschungsinstitut Oberwolfach, 2019-02-11)For compact sets K⊂Cd, we introduce a subalgebra AD(K) of A(K), which allows us to obtain Mergelyan type theorems for products of planar compact sets as well as for graphs of functions. -
Generalized Vector Cross Products and Killing Forms on Negatively Curved Manifolds
[OWP-2018-17] (Mathematisches Forschungsinstitut Oberwolfach, 2018-07-17)Motivated by the study of Killing forms on compact Riemannian manifolds of negative sectional curvature, we introduce the notion of generalized vector cross products on Rn and give their classification. Using ... -
Global Solutions to Stochastic Wave Equations with Superlinear Coefficients
[OWP-2019-26] (Mathematisches Forschungsinstitut Oberwolfach, 2019-11-13)We prove existence and uniqueness of a random field solution (u(t,x);(t,x)∈[0,T]×Rd) to a stochastic wave equation in dimensions d=1,2,3 with diffusion and drift coefficients of the form $|x| ... -
Global Variants of Hartogs' Theorem
[OWP-2018-24] (Mathematisches Forschungsinstitut Oberwolfach, 2018-11-06)Hartogs' theorem asserts that a separately holomorphic function, defined on an open subset of Cn, is holomorphic in all the variables. We prove a global variant of this theorem for functions defined on an open ... -
Hölder Continuity of the Spectra for Aperiodic Hamiltonians
[OWP-2019-05] (Mathematisches Forschungsinstitut Oberwolfach, 2019-02-26)We study the spectral location of a strongly pattern equivariant Hamiltonians arising through configurations on a colored lattice. Roughly speaking, two configurations are "close to each other" if, up to a translation, ... -
The Magic Square of Reflections and Rotations
[OWP-2018-13] (Mathematisches Forschungsinstitut Oberwolfach, 2018-07-01)We show how Coxeter’s work implies a bijection between complex reflection groups of rank two and real reflection groups in 0(3). We also consider this magic square of reflections and rotations in the framework of Clifford ... -
Max-Linear Models on Infinite Graphs Generated by Bernoulli Bond Percolation
[OWP-2018-09] (Mathematisches Forschungsinstitut Oberwolfach, 2018-05-17)We extend previous work of max-linear models on finite directed acyclic graphs to infinite graphs, and investigate their relations to classical percolation theory. We formulate results for the oriented square lattice graph ... -
Metric Connections with Parallel Skew-Symmetric Torsion
[OWP-2018-16] (Mathematisches Forschungsinstitut Oberwolfach, 2018-07-16)A geometry with parallel skew-symmetric torsion is a Riemannian manifold carrying a metric connection with parallel skew-symmetric torsion. Besides the trivial case of the Levi-Civita connection, geometries with non-vanishing ... -
On a Group Functor Describing Invariants of Algebraic Surfaces
[OWP-2019-08] (Mathematisches Forschungsinstitut Oberwolfach, 2019-03-01)Liedtke (2008) has introduced group functors K and ˜K, which are used in the context of describing certain invariants for complex algebraic surfaces. He proved that these functors are connected to the theory of ... -
On the Gauss Algebra of Toric Algebras
[OWP-2018-07] (Mathematisches Forschungsinstitut Oberwolfach, 2018-04-25)Let A be a K-subalgebra of the polynomial ring S=K[x1,…,xd] of dimension d, generated by finitely many monomials of degree r. Then the Gauss algebra G(A) of A is generated by monomials of ... -
On the Invariants of the Cohomology of Complements of Coxeter Arrangements
[OWP-2018-21] (Mathematisches Forschungsinstitut Oberwolfach, 2018-10-22)We refine Brieskorn's study of the cohomology of the complement of the reflection arrangement of a finite Coxeter group W. As a result we complete the verification of a conjecture by Felder and Veselov that gives an explicit ... -
Real Analyticity is Concentrated in Dimension 2
[OWP-2018-23] (Mathematisches Forschungsinstitut Oberwolfach, 2018-11-05)We prove that a real-valued function on a real analytic manifold is analytic whenever all its restrictions to 2-dimensional analytic submanifolds are analytic functions. We also obtain analogous results in the framework ... -
Reflective Prolate-Spheroidal Operators and the KP/KdV Equations
[OWP-2019-24] (Mathematisches Forschungsinstitut Oberwolfach, 2019-11-05)Commuting integral and differential operators connect the topics of Signal Processing, Random Matrix Theory, and Integrable Systems. Previously, the construction of such pairs was based on direct calculation and ...