Browsing 1 - Oberwolfach Preprints (OWP) by Title
Now showing items 218-237 of 399
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Non-integrated defect relation for meromorphic maps of complete Kähler manifolds into a projective variety intersecting hypersurfaces
[OWP-2010-19] (Mathematisches Forschungsinstitut Oberwolfach, 2010)In 1985, Fujimoto established a non-integrated defect relation for meromorphic maps of complete Kähler manifolds into the complex projective space intersecting hyperplanes in general position. In this paper, we generalize ... -
Non-Standard Behavior of Density Estimators for Sums of Squared Observations
[OWP-2008-07] (Mathematisches Forschungsinstitut Oberwolfach, 2008-03-11)It has been shown recently that, under an appropriate integrability condition, densities of functions of independent and identically distributed random variables can be estimated at the parametric rate by a local U-statistic, ... -
Non-stationary multivariate subdivision: joint spectral radius and asymptotic similarity
[OWP-2013-20] (Mathematisches Forschungsinstitut Oberwolfach, 2013-10-29)In this paper we study scalar multivariate non-stationary subdivision schemes with a general integer dilation matrix. We present a new numerically efficient method for checking convergence and Hölder ... -
Noncommutative Marked Surfaces
[OWP-2015-16] (Mathematisches Forschungsinstitut Oberwolfach, 2015-11-18)The aim of the paper is to attach a noncommutative cluster-like structure to each marked surface $\Sigma$. This is a noncommutative algebra $\mathcal{A}_\Sigma$ generated by “noncommutative geodesics” between marked points ... -
Noncommutative topological entropy of endomorphismus of Cuntz Algebras
[OWP-2008-12] (Mathematisches Forschungsinstitut Oberwolfach, 2008-03-16)Noncommutative topological entropy estimates are obtained for ‘finite range’ endomorphisms of Cuntz algebras,generalising known results for the canonical shift endomorphisms. Exact values are computed for a class of ... -
Noncompact harmonic manifolds
[OWP-2013-08] (Mathematisches Forschungsinstitut Oberwolfach, 2013-04-10)The Lichnerowicz conjecture asserts that all harmonic manifolds are either flat or locally symmetric spaces of rank 1. This conjecture has been proved by Z.I. Szab ́o [Sz] for harmonic manifolds with compact universal ... -
Nondegenerate Invariant Symmetric Bilinear Forms on Simple Lie Superalgebras in Characteristic 2
[OWP-2020-02] (Mathematisches Forschungsinstitut Oberwolfach, 2020-02-04)As is well-known, the dimension of the space of non-degenerate invariant symmetric bilinear forms (NISes) on any simple finite-dimensional Lie algebra or Lie superalgebra is equal to at most 1 if the characteristic of the ... -
Nonexistence of Subcritical Solitary Waves
[OWP-2020-06] (Mathematisches Forschungsinstitut Oberwolfach, 2020-03-15)We prove the nonexistence of two-dimensional solitary gravity water waves with subcritical wave speeds and an arbitrary distribution of vorticity. This is a longstanding open problem, and even in the irrotational case there ... -
Nonlinear matroid optimization and experimental design
[OWP-2007-06] (Mathematisches Forschungsinstitut Oberwolfach, 2007-03-24)We study the problem of optimizing nonlinear objective functions over matroids presented by oracles or explicitly. Such functions can be interpreted as the balancing of multi-criteria optimization. We provide a combinatorial ... -
Nonlinear Multi-Parameter Eigenvalue Problems for Systems of Nonlinear Ordinary Differential Equations Arising in Electromagnetics
[OWP-2014-15] (Mathematisches Forschungsinstitut Oberwolfach, 2014-12-20)We investigate a generalization of one-parameter eigenvalue problems arising in the theory of nonlinear waveguides to a more general nonlinear multiparameter eigenvalue problem for a nonlinear operator. Using an integral ... -
Nonlinear Optimization for Matroid Intersection and Extensions
[OWP-2008-14] (Mathematisches Forschungsinstitut Oberwolfach, 2008-03-17)We address optimization of nonlinear functions of the form $f(W_x)$ , where $f : \mathbb{R}^d \to \mathbb{R}$ is a nonlinear function, $W$ is a $d \times n$ matrix, and feasible $x$ are in some large finite set $\mathcal{F}$ ... -
Nonlinear optimization over a Weighted Independence System
[OWP-2008-10] (Mathematisches Forschungsinstitut Oberwolfach, 2008-03-14)We consider the problem of optimizing a nonlinear objective function over a weighted independence system presented by a linear-optimization oracle. We provide a polynomial-time algorithm that determines an r-best solution ... -
A note on delta hedging in markets with jumps
[OWP-2011-23] (Mathematisches Forschungsinstitut Oberwolfach, 2011-05-21)Modelling stock prices via jump processes is common in financial markets. In practice, to hedge a contingent claim one typically uses the so-called delta-hedging strategy. This strategy stems from the Black–Merton–Scholes ... -
A Note on Endpoint Bochner-Riesz Estimates
[OWP-2023-17] (Mathematisches Forschungsinstitut Oberwolfach, 2023-11-27)We revisit an $\varepsilon$-removal argument of Tao to obtain sharp $L^p \to L^r(L^p)$ estimates for sums of Bochner-Riesz bumps which are conditional on non-endpoint bounds for single scale bumps. These can be used to ... -
A note on k[z]-Automorphisms in Two Variables
[OWP-2008-17] (Mathematisches Forschungsinstitut Oberwolfach, 2008)We prove that for a polynomial $f \in k[x, y, z]$ equivalent are: (1)$f$ is a $k[z]$-coordinate of $k[z][x,y]$, and (2) $k[x, y, z]/(f)\cong k^[2]$ and $f(x,y,a)$ is a coordinate in $k[x,y]$ for some $a \in k$. This solves ... -
Numerical Invariants and Moduli Spaces for Line Arrangements
[OWP-2017-02] (Mathematisches Forschungsinstitut Oberwolfach, 2017-02-01)Using several numerical invariants, we study a partition of the space of line arrangements in the complex projective plane, given by the intersection lattice types. We offer also a new characterization of the free plane ... -
Observability of systems with delay convoluted observation
[OWP-2014-10] (Mathematisches Forschungsinstitut Oberwolfach, 2014-05-13)This paper analyzes finite dimensional linear time-invariant systems with observation of a delay, where that delay satisfies a particular implicit relation with the state variables, rendering the entire problem nonlinear. ... -
Obtaining Error-Minimizing Estimates and Universal Entry-Wise Error Bounds for Low-Rank Matrix Completion
[OWP-2013-12] (Mathematisches Forschungsinstitut Oberwolfach, 2013-06-10)We propose a general framework for reconstructing and denoising single entries of incomplete and noisy entries. We describe: effective algorithms for deciding if and entry can be reconstructed and, if so, for reconstructing ... -
Octonion Polynomials with Values in a Subalgebra
[OWP-2020-21] (Mathematisches Forschungsinstitut Oberwolfach, 2020-10-22)In this paper, we prove that given an octonion algebra $A$ over a field $F$, a subring $E \subseteq F$ and an octonion $E$-algebra $R$ inside $A$, the set $S$ of polynomials $f(x) \in A[x]$ satisfying $f(R) \subseteq R$ ... -
On a Cheeger Type Inequality in Cayley Graphs of Finite Groups
[OWP-2019-20] (Mathematisches Forschungsinstitut Oberwolfach, 2019-07-22) - (7 July - 7 October 2017)Let $G$ be a finite group. It was remarked by Breuillard-Green-Guralnick-Tao that if the Cayley graph $C(G,S)$ is an expander graph and is non-bipartite then the spectrum of the adjacency operator $T$ is bounded away from ...