Browsing 1 - Oberwolfach Preprints (OWP) by Title
Now showing items 137-156 of 357
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Inductive Freeness of Ziegler’s Canonical Multiderivations for Reflection Arrangements
[OWP-2017-14] (Mathematisches Forschungsinstitut Oberwolfach, 2017-04-30)Let $A$ be a free hyperplane arrangement. In 1989, Ziegler showed that the restriction $A''$ of $A$ to any hyperplane endowed with the natural multiplicity is then a free multiarrangement. We initiate a study of the stronger ... -
Infeasibility certificates for linear matrix inequalities
[OWP-2011-28] (Mathematisches Forschungsinstitut Oberwolfach, 2011-05-25)Farkas' lemma is a fundamental result from linear programming providing linear certi cates for infeasibility of systems of linear inequalities. In semidefinite programming, such linear certificates only exist for strongly ... -
The ingram conjecture
[OWP-2010-02] (Mathematisches Forschungsinstitut Oberwolfach, 2010-03-8)We prove the Ingram Conjecture, i.e., we show that the inverse limit spaces of every two tent maps with different slopes in the interval [1,2] are non-homeomorphic. Based on the structure obtained from the proof, we also ... -
The Initial and Terminal Cluster Sets of an Analytic Curve
[OWP-2016-25] (Mathematisches Forschungsinstitut Oberwolfach, 2016-12-21)For an analytic curve $\gamma : (a,b) \to \mathbb{C}$, the set of values approaches by $\gamma(t)$, as $t ↘a$ and as $t↗b$ can be any two continuua of $\mathbb{C} \cup \{\infty\}$. -
Instability of point defects in a two-dimensional nematic liquid crystal model
[OWP-2015-05] (Mathematisches Forschungsinstitut Oberwolfach, 2015-07-29)We study a class of symmetric critical points in a variational 2$D$ Landau - de Gennes model where the state of nematic liquid crystals is described by symmetric traceless $3 \times 3$ matrices. These critical points play ... -
Interpolation in Bernstein and Paley-Wiener Spaces
[OWP-2008-04] (Mathematisches Forschungsinstitut Oberwolfach, 2008-03-08)We construct closed sets S of arbitrarily small measure with the property: given any discrete set L, every l-function on L can be interpolated by an L-function with spectrum on F. This should be contrasted against ... -
An introduction to heavy-tailed and sibexponential distributions
[OWP-2009-13] (Mathematisches Forschungsinstitut Oberwolfach, 2009-03-07)This text studies heavy-tailed distributions in probability theory, and especially convolutions of such distributions. The mail goal is to provide a complete and comprehensive introduction to the theory of long-tailed ... -
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 ... -
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 ... -
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 ... -
Killing Tensors on Tori
[OWP-2016-20] (Mathematisches Forschungsinstitut Oberwolfach, 2016-11-10)We show that Killing tensors on conformally at n-dimensional tori whose conformal factor only depends on one variable, are polynomials in the metric and in the Killing vector fields. In other words, every first integral ... -
l-Torsion Bounds for the Class Group of Number Fields with an l -Group as Galois Group
[OWP-2020-11] (Mathematisches Forschungsinstitut Oberwolfach, 2020-05-04)We describe the relations among the $\ell$-torsion conjecture for $\ell$-extensions, the discriminant multiplicity conjecture for nilpotent extensions and a conjecture of Malle giving an upper bound for the number of ... -
Late-Time Behaviour of Israel Particles in a FLRW Spacetime with Λ>0
[OWP-2016-19] (Mathematisches Forschungsinstitut Oberwolfach, 2016-10)In this paper we study the relativistic Boltzmann equation in a spatially flat FLRW space-time. We consider Israel particles, which are the relativistic counterpart of the Maxwellian particles, and obtain global-in-time ... -
Legendrian Knots in Lens Spaces
[OWP-2011-01] (Mathematisches Forschungsinstitut Oberwolfach, 2011)In this note, we first classify all topological torus knots lying on the Heegaard torus in Lens spaces, and then we classify Legendrian representatives of torus knots. We show that all Legendrian torus knots in universally ... -
Legendrian Lens Space Surgeries
[OWP-2016-10] (Mathematisches Forschungsinstitut Oberwolfach, 2016-06-17)We show that every tight contact structure on any of the lens spaces $L(ns^2 - s + 1,s^2)$ with $n\geq 2, s \geq 1$, can be obtained by a single Legendrian surgery along a suitable Legendrian realisation of the negative ... -
Legendrian rational unknots in lens spaces
[OWP-2013-06] (Mathematisches Forschungsinstitut Oberwolfach, 2013-03-14)We classify Legendrian rational unknots with tight complements in the lens spaces $L(p,1)$ up to coarse equivalence. As an example of the general case, this classification is also worked out for $L(5, 2)$. The knots are ... -
Lifting Spectral Triples to Noncommutative Principal Bundles
[OWP-2021-02] (Mathematisches Forschungsinstitut Oberwolfach, 2021-01-11)Given a free action of a compact Lie group $G$ on a unital C*-algebra $\mathcal{A}$ and a spectral triple on the corresponding fixed point algebra $\mathcal{A}^G$, we present a systematic and in-depth construction of ... -
Linear Syzygies, Hyperbolic Coxeter Groups and Regularity
[OWP-2017-15] (Mathematisches Forschungsinstitut Oberwolfach, 2017-05-24)We build a new bridge between geometric group theory and commutative algebra by showing that the virtual cohomological dimension of a Coxeter group is essentially the regularity of the Stanley–Reisner ring of its nerve. ... -
Linking and Closed Orbits
[OWP-2013-15] (Mathematisches Forschungsinstitut Oberwolfach, 2013-06-10)We show that the Lagrangian of classical mechanics on a Riemannian manifold of bounded geometry carries a periodic solution of motion with prescribed energy, provided the potential satis es an asymptotic growth ... -
Local asymptotics for the area of random walk excursions
[OWP-2013-19] (Mathematisches Forschungsinstitut Oberwolfach, 2013-09-05)We prove a local limit theorem for the area of the positive exursion of random walks with zero mean and finite variance. Our main result complements previous work of Caravenna and Chaumont, Sohier, as well as ...