• Stochastic mean payoff game: smoothed analysis and approximation schemes 

      [OWP-2010-22] Boros, Endre; Elbassioni, Khaled; Fouz, Mahmoud; Gurvich, Vladimir; Manthey, Bodo (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] Benson, David J.; Iyengar, Srikanth B.; Krause, Henning (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] Györfi, László; Walk, Harro (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] Kawohl, Bernhard; Kutev, Nickolai (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] Izhakian, Zur; Knebusch, Manfred; Rowen, Louis (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] Izhakian, Zur; Rowen, Louis (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] Knebusch, Manfred; Rowen, Louis; Izhakian, Zur (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] Izhakian, Zur; Knebusch, Manfred; Rowen, Louis (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] Balazard, Michel; Martin, Bruno (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] Herfort, Wolfgang; Hofmann, Karl Heinrich; Kramer, Linus; Russo, Francesco G. (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] Hering, Milena; Maclagan, Diane (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] Grantcharov, Dimitar; Serganova, Vera (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] Chevallier, Julien; Melnykova, Anna; Tubikanec, Irene (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] Öztürk, Ferit; Salepci, Nermin (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] Burban, Igor; Drozd, Jurij A. (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 ...
    • Time and band limiting for matrix valued functions, an example 

      [OWP-2015-08] Grünbaum, F. A.; Pacharoni, I.; Zurrián, Ignacio Nahuel (Mathematisches Forschungsinstitut Oberwolfach, 2015-07-29)
      The main purpose of this paper is to extend to a situation involving matrix valued orthogonal polynomials and spherical functions, a result that traces its origin and its importance to work of Claude Shannon in laying the ...
    • Time Discretization Schemes for Hyperbolic Systems on Networks by ε-Expansion 

      [OWP-2019-03] Altmann, Robert; Zimmer, Christoph (Mathematisches Forschungsinstitut Oberwolfach, 2019-02-12)
      We consider partial differential equations on networks with a small parameter $\epsilon$, which are hyperbolic for $\epsilon>0$ and parabolic for $\epsilon=0$. With a combination of an $\epsilon$-expansion and Runge-Kutta ...
    • Torsion-free Covers of Solvable Minimax Groups 

      [OWP-2015-15] Kropholler, Peter H.; Lorensen, Karl (Mathematisches Forschungsinstitut Oberwolfach, 2015-11-18)
      We prove that every finitely generated solvable minimax group can be realized as a quotient of a torsion-free solvable minimax group. This result has an application to the investigation of random walks on finitely generated ...
    • Totally Acyclic Complexes 

      [OWP-2016-14] Estrada, Sergio; Fu, Xianhui; Iacob, Alina (Mathematisches Forschungsinstitut Oberwolfach, 2016-08-17)
      We prove first (Proposition 3) that, over any ring $R$, an acyclic complex of projective modules is totally acyclic if and only if the cycles of every acyclic complex of Gorenstein projective modules are Gorenstein projective. ...
    • The Tutte Polynomial of Ideal Arrangements 

      [OWP-2018-28] Randriamaro, Hery (Mathematisches Forschungsinstitut Oberwolfach, 2018-12-21)
      The Tutte polynomial is originally a bivariate polynomial enumerating the colorings of a graph and of its dual graph. But it reveals more of the internal structure of the graph like its number of forests, of spanning ...