Now showing items 307-326 of 353

• #### Spherical Arc-Length as a Global Conformal Parameter for Analytic Curves in the Riemann Sphere ﻿

[OWP-2016-21] (Mathematisches Forschungsinstitut Oberwolfach, 2016-11-11)
We prove that for every analytic curve in the complex plane $\mathbb{C}$, Euclidean and spherical arc-lengths are global conformal parameters. We also prove that for any analytic curve in the hyperbolic plane, hyperbolic ...
• #### Splitting Necklaces, with Constraints ﻿

[OWP-2020-03] (Mathematisches Forschungsinstitut Oberwolfach, 2020-02-11)
We prove several versions of Alon's "necklace-splitting theorem", subject to additional constraints, as illustrated by the following results. (1) The "almost equicardinal necklace-splitting theorem" claims that, without ...
• #### Square wave periodic solutions of a differential delay equation ﻿

[OWP-2014-09] (Mathematisches Forschungsinstitut Oberwolfach, 2014-05-13)
We prove the existence of periodic solutions of the differential delay equation $\varepsilon\dot{x}(t) + x(t)= f(x(t-1)), \varepsilon>0$ under the assumptions that the continuous nonlinearity $f(x)$ satisfies the negative ...
• #### Stein's method for dependent random variables occuring in statistical mechanics ﻿

[OWP-2009-09] (Mathematisches Forschungsinstitut Oberwolfach, 2009-03-03)
We obtain rates of convergence in limit theorems of partial sums $S_n$ for certain sequences of dependent, identically distributed random variables, which arise naturally in statistical mechanics, in particular, in the ...
• #### Steinberg groups for Jordan pairs ﻿

[OWP-2011-29] (Mathematisches Forschungsinstitut Oberwolfach, 2011-05-26)
We introduce categories of groups with commutator relations with respect to root groups and Weyl elements, permuting the root groups. This allows us to view the classical Steinberg groups, for example the Steinberg group ...
• #### Stochastic mean payoff game: smoothed analysis and approximation schemes ﻿

[OWP-2010-22] (Mathematisches Forschungsinstitut Oberwolfach, 2010-03-20)
We consider two-person zero-sum stochastic mean payoff games with perfect information modeled by a digraph with black, white, and random vertices. These BWR-games games are polynomially equivalent with the classical Gillette ...
• #### Stratifying modular representations of finite groups ﻿

[OWP-2008-20] (Mathematisches Forschungsinstitut Oberwolfach, 2008-03-20)
We classify localising subcategories of the stable module category of a finite group that are closed under tensor product with simple (or, equivalently all) modules. One application is a proof of the telescope conjecture ...
• #### 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 ...
• #### A study on gradient blow up for viscosity solutions of fully nonlinear, uniformly elliptic equations ﻿

[OWP-2009-10] (Mathematisches Forschungsinstitut Oberwolfach, 2009-03-04)
We investigate sharp conditions for boundary and interior gradient estimates of continuous viscosity solutions to fully nonlinear, uniformly elliptic equations under Dirichlet boundary conditions. When these conditions are ...
• #### Supertropical linear algebra ﻿

[OWP-2010-14] (Mathematisches Forschungsinstitut Oberwolfach, 2010)
The objective of this paper is to lay out the algebraic theory of supertropical vector spaces and linear algebra, utilizing the key antisymmetric relation of "ghost surpasses." Special attention is paid to the various ...
• #### Supertropical Matrix Algebra III : Powers of Matrices and Generalized Eigenspaces ﻿

[OWP-2010-20] (Mathematisches Forschungsinstitut Oberwolfach, 2010)
We investigate powers of supertropical matrices, with special attention to the role of the coefficients of the supertropical characteristic polynomial (especially the supertropical trace) in controlling the rank of a power ...
• #### Supertropical Quadratic Forms I ﻿

[OWP-2013-27] (Mathematisches Forschungsinstitut Oberwolfach, 2013)
We initiate the theory of a quadratic form q over a semiring $R$. As customary, one can write $q(x+y)=q(x)+q(y)+b(x,y)$, where b is a companion bilinear form. But in contrast to the ring-theoretic case, the companion ...
• #### Supertropical semirings and supervaluations ﻿

[OWP-2010-05] (Mathematisches Forschungsinstitut Oberwolfach, 2010)
We interpret a valuation $\upsilon$ on a ring $R$ as a map $\upsilon:R \rightarrow M$ into a so called bipotent semiring $M$ (the usual max-plus setting), and then define a supervaluation $\varphi$ as a suitable map into ...
• #### Sur le Minimum de la Fonction de Brjuno ﻿

[OWP-2018-26] (Mathematisches Forschungsinstitut Oberwolfach, 2018-12-11)
The Brjuno function attains a strict global minimum at the golden section.
• #### The Sylow Structure of Scalar Automorphism Groups ﻿

[OWP-2018-05] (Mathematisches Forschungsinstitut Oberwolfach, 2018-03-22)
For any locally compact abelian periodic group A its automorphism group contains as a subgroup those automorphisms that leave invariant every closed subgroup of A, to be denoted by SAut(A). This subgroup is again a locally ...
• #### The T-Graph of a Multigraded Hilbert Scheme ﻿

[OWP-2011-34] (Mathematisches Forschungsinstitut Oberwolfach, 2011)
The $T$-graph of a multigraded Hilbert scheme records the zero and one-dimensional orbits of the $T=(K^*)^n$ action on the Hilbert scheme induced from the $T$-action on $\mathbb{A}^n$. It has vertices the $T$-fixed points, ...
• #### Tensor Representations of q(∞) ﻿

[OWP-2016-09] (Mathematisches Forschungsinstitut Oberwolfach, 2016-06-17)
We introduce a symmetric monoidal category of modules over the direct limit queer superalgebra $\mathfrak{q}(\infty)$. The category can be defined in two equivalent ways with the aid of the large annihilator condition. ...
• #### Theoretical Analysis and Simulation Methods for Hawkes Processes and their Diffusion Approximation ﻿

[OWP-2020-09] (Mathematisches Forschungsinstitut Oberwolfach, 2020-03-30)
Oscillatory systems of interacting Hawkes processes with Erlang memory kernels were introduced in Ditlevsen and Löcherbach (2017). They are piecewise deterministic Markov processes (PDMP) and can be approximated by a ...
• #### There is a unique real tight contact 3-ball ﻿

[OWP-2010-01] (Mathematisches Forschungsinstitut Oberwolfach, 2010)
We prove that there is a unique real tight contact structure on the 3-ball with convex boundary up to isotopy through real tight contact structures. We also give a partial classification of the real tight solid tori with ...
• #### Tilting on non-commutative rational projective curves ﻿

[OWP-2009-14] (Mathematisches Forschungsinstitut Oberwolfach, 2009-03-08)
In this article we introduce a new class of non-commutative projective curves and show that in certain cases the derived category of coherent sheaves on them has a tilting complex. In particular, we prove that the right ...