Browsing 1  Oberwolfach Preprints (OWP) by Title
Now showing items 286305 of 405

The PelletierRessayre Hidden Symmetry for LittlewoodRichardson Coefficients
[OWP202018] (Mathematisches Forschungsinstitut Oberwolfach, 20200908)We prove an identity for Littlewood–Richardson coefficients conjectured by Pelletier and Ressayre. The proof relies on a novel birational involution defined over any semifield. 
Plethysms, replicated Schur functions and series, with applications to vertex operators
[OWP201012] (Mathematisches Forschungsinstitut Oberwolfach, 20100314)Specializations of Schur functions are exploited to define and evaluate the Schur functions $s_\lambda [\alpha X]$ and plethysms $s_\lambda [\alpha s_\nu(X))]$ for any $\alpha$integer, real or complex. Plethysms are then ... 
Plethystic Vertex Operators and BosonFermion Correspondences
[OWP201611] (Mathematisches Forschungsinstitut Oberwolfach, 20160617)We study the algebraic properties of plethystic vertex operators, introduced in J. Phys. A: Math. Theor. 43 405202 (2010), underlying the structure of symmetric functions associated with certain generalized universal ... 
Pointwise hyperbolicity implies uniform hyperbolicity
[OWP200906] (Mathematisches Forschungsinstitut Oberwolfach, 20090223)We provide a general mechanism for obtaining uniform information from pointwise data. A sample result is that if a diffeomorphism of a compact Riemannian manifold has pointwise expanding and contracting continuous invariant ... 
Polynomiality, wall crossings and tropical geometry of rational double hurwitz cycles
[OWP201213] (Mathematisches Forschungsinstitut Oberwolfach, 20121204)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 ... 
Positive Line Bundles Over the Irreducible Quantum Flag Manifolds
[OWP202001] (Mathematisches Forschungsinstitut Oberwolfach, 20200203)Noncommutative Kähler structures were recently introduced by the third author as a framework for studying noncommutative Kähler geometry on quantum homogeneous spaces. It was subsequently observed that the notion of a ... 
Positive Margins and Primary Decomposition
[OWP201206] (Mathematisches Forschungsinstitut Oberwolfach, 2012)We study random walks on contingency tables with fixed marginals, corresponding to a (loglinear) hierarchical model. If the set of allowed moves is not a Markov basis, then there exist tables with the same marginals that ... 
Positive recurrence of piecewise OrnteinUhlenbeck processes and common quadratic Lyapunov functions
[OWP201126] (Mathematisches Forschungsinstitut Oberwolfach, 2011)We study the positive recurrence of piecewise OrnsteinUhlenbeck (OU) diffusion processes, which arise from manyserver queueing systems with phasetype service requirements. These diffusion processes exhibit different ... 
Positivity of the Tsystem cluster algebra
[OWP200921] (Mathematisches Forschungsinstitut Oberwolfach, 20090314)We give the path model solution for the cluster algebra variables of the $A_r$ Tsystem with generic boundary conditions. The solutions are partition functions of (strongly) nonintersecting paths on weighted graphs. The ... 
A potential reduction algorithm for twoperson zerosum mean payoff stochastic games
[OWP201519] (Mathematisches Forschungsinstitut Oberwolfach, 2015)We suggest a new algorithm for twoperson zerosum undiscounted stochastic games focusing on stationary strategies. Given a positive real $\epsilon$, let us call a stochastic game $\epsilon$ergodic, if its values from any ... 
Preconditioning of Block Tridiagonal Matrices
[OWP200805] (Mathematisches Forschungsinstitut Oberwolfach, 20080309)Preconditioning methods via approximate block factorization for block tridiagonal matrices are studied. Bounds for the resulting condition numbers are given, and two methods for the recursive construction of the approximate ... 
Prediction and Quantification of Individual Athletic Performance
[OWP201511] (Mathematisches Forschungsinstitut Oberwolfach, 20150827)We present a novel, quantitative view on the human athletic performance of individuals. We obtain a predictor for athletic running performances, a parsimonious model, and a training state summary consisting of three numbers, ... 
Products of pairs of Dehn twists and maximal real Lefschetz fibrations
[OWP201132] (Mathematisches Forschungsinstitut Oberwolfach, 2011)We address the problem of existence and uniqueness of a factorization of a given element of the modular group into a product of two Dehn twists. As a geometric application, we conclude that any maximal real elliptic ... 
Proof Mining and the Convex Feasibility Problem : the Curious Case of Dykstra's Algorithm
[OWP202406] (Mathematisches Forschungsinstitut Oberwolfach, 20240715)In a recent proof mining application, the prooftheoretical analysis of Dykstra's cyclic projections algorithm resulted in quantitative information expressed via primitive recursive functionals in the sense of Gödel. This ... 
Proof mining in metric fixed point theory and ergodic theory
[OWP200905] (Mathematisches Forschungsinstitut Oberwolfach, 2009)In this survey we present some recent applications of proof mining to the fixed point theory of (asymptotically) nonexpansive mappings and to the metastability (in the sense of Terence Tao) of ergodic averages in uniformly ... 
The PseudoHyperresolution and Applications
[OWP201717] (Mathematisches Forschungsinstitut Oberwolfach, 20170704)Resolving objects in an abelian category by injective (projective) resolutions is a fundamental problem in mathematics, and this article aims at introducing a particular solution called “Pseudohyperresolutions”. This ... 
A PseudoPolynomial Algorithm for Mean Payoff Stochastic Games with Perfect Information and Few Random Positions
[OWP201520] (Mathematisches Forschungsinstitut Oberwolfach, 2015)We consider twoperson zerosum stochastic mean payoff games with perfect information, or BWRgames, given by a digraph $G = (V,E)$, with local rewards $r : E \to \mathbb{Z}$, and three types of positions: black $V_B$, ... 
A Quantitative Analysis of the “LionMan” Game
[OWP201918] (Mathematisches Forschungsinstitut Oberwolfach, 20190708)In this paper we analyze, based on an interplay between ideas and techniques from logic and geometric analysis, a pursuitevasion game. More precisely, we focus on a discrete lion and man game with an $\varepsilon$capture ... 
Quantities that frequencydependent selection maximizes
[OWP200818] (Mathematisches Forschungsinstitut Oberwolfach, 20080318)We consider a model of frequencydependent selection, to which we refer as the Wildcard Model, that accommodates as particular cases a number of diverse models of biologically specific situations. Two very different ... 
QuasiEquilibria and Click Times for a Variant of Muller's Ratchet
[OWP202218] (Mathematisches Forschungsinstitut Oberwolfach, 20221130)Consider a population of $N$ individuals, each of them carrying a type in $\mathbb N_0$. The population evolves according to a Moran dynamics with selection and mutation, where an individual of type $k$ has the same selective ...