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Now showing items 1-20 of 28

    • On the autonomous metric on groups of Hamiltonian diffeomorphisms of closed hyperbolic surfaces 

      [OWP-2013-18] Brandenbursky, Michael (Mathematisches Forschungsinstitut Oberwolfach, 2013-07-23)
      Let $\Sigma_g$ be a closed hyperbolic surface of genus $g$ and let Ham($\Sigma_ g$) be the group of Hamiltonian diffeomorphisms of $\Sigma_g$. The most natural word metric on this group is the autonomous metric. It has ...
    • 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 ...
    • Right Simple Singularities in Positive Characteristic 

      [OWP-2013-28] Greuel, Gert-Martin; Nguyen, Hong Duc (Mathematisches Forschungsinstitut Oberwolfach, 2013)
      We classify isolated singularities $f \in K[[x_1,...,x_n]]$, which are simple, i.e. have no moduli, w.r.t. right equivalence, where $K$ is an algebraically closed field of characteristic $p>0$. For $K=\mathbb{R}$ or ...
    • Mesh Ratios for Best-Packing and Limits of Minimal Energy Configurations 

      [OWP-2013-13] Bondarenko, A. V.; Hardin, Douglas P.; Saff, Edward B. (Mathematisches Forschungsinstitut Oberwolfach, 2013-06-10)
      For $N$-point best-packing configurations $\omega_N$ on a compact metric space $(A, \rho)$, we obtain estimates for the mesh-separation ratio $\gamma(\rho_N , A)$, which is the quotient of the covering radius of $\omega_N$ ...
    • The algebraic combinatorial approach for low-rank matrix completion 

      [OWP-2013-05] Király, Franz J.; Theran, Louis; Ryota,Tomioka; Uno, Takeaki (Mathematisches Forschungsinstitut Oberwolfach, 2013-03-14)
      We propose an algebraic combinatorial framework for the problem of completing partially observed low-rank matrices. We show that the intrinsic properties of the problem, including which entries can be reconstructed, and ...
    • Obtaining Error-Minimizing Estimates and Universal Entry-Wise Error Bounds for Low-Rank Matrix Completion 

      [OWP-2013-12] Király, Franz J.; Theran, Louis (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 ...
    • On Concentrators and Related Approximation Constants 

      [OWP-2013-14] Bondarenko, A. V.; Prymak, A.; Radchenko, D. (Mathematisches Forschungsinstitut Oberwolfach, 2013-06-10)
      Pippenger ([Pip77]) showed the existence of (6m, 4m, 3m, 6)-concentrator for each positive integer m using a probabilistic method. We generalize his approach and prove existence of (6m, 4m, 3m, 5.05)-concentrator (which ...
    • Even-homogeneous supermanifolds on the complex projective line 

      [OWP-2013-02] Vishnyakova, E. G. (Mathematisches Forschungsinstitut Oberwolfach, 2013-03-14)
      The classification of even-homogeneous complex supermanifolds of dimension $1|m$, $m<=3$, on $\mathbb{CP}^1$ up to isomorphism is given. An explicit description of such supermanifolds in terms of local charts and coordinates ...
    • Enhanced Spatial Skin-Effect for Free Vibrations of a Thick Cascade Junction with "Super Heavy" Concentrated Masses 

      [OWP-2013-26] Čečkin, Grigorij A.; Mel'nyk, Taras A. (Mathematisches Forschungsinstitut Oberwolfach, 2013-12-13)
      The asymptotic behavior (as $\varepsilon \to 0$) of eigenvalues and eigenfunctions of a boundary-value problem for the Laplace operator in a thick cascade junction with concentrated masses is studied. This cascade junction ...
    • A Relation Between N-Qubit and 2N-1-Qubit Pauli Groups via Binary LGr(N,2N) 

      [OWP-2013-25] Holweck, F. G.; Saniga, Metod; Lévay, Péter (Mathematisches Forschungsinstitut Oberwolfach, 2013-12-09)
      Employing the fact that the geometry of the $N$-qubit ($N\geq 2$) Pauli group is embodied in the structure of the symplectic polar space $\mathcal{W}(2N-1, 2)$ and using properties of the Lagrangian Grassmannian $LGr(N, ...
    • On the Derived Category of Grassmannians in Arbitrary Characteristic 

      [OWP-2013-24] Buchweitz, Ragnar-Olaf; Leuschke, Graham J.; Van den Bergh, Michel (Mathematisches Forschungsinstitut Oberwolfach, 2013-12-09)
      In this paper we consider Grassmannians in arbitrary characteristic. Generalizing Kapranov's well-known characteristic-zero results we construct dual exceptional collections on them (which are however not strong) as well ...
    • Mehler-Heine asymptotics of a class of generalized hypergeometric polynomials : 

      [OWP-2013-23] Bracciali, Cleonice F.; Moreno-Balcázar, Juan José (Mathematisches Forschungsinstitut Oberwolfach, 2013-10-29)
      We obtain a Mehler–Heine type formula for a class of generalized hypergeometric polynomials. This type of formula describes the asymptotics of polynomials scale conveniently. As a consequence of this formula, we obtain ...
    • Very general monomial valuations of P2 and a Nagata type conjecture 

      [OWP-2013-22] Dumnicki, Marcin; Harbourne, Brian; Küronya, Alex; Roé, Joaquim; Szemberg, Tomasz (Mathematisches Forschungsinstitut Oberwolfach, 2013-10-29)
    • On conjugacy of MASAs and the outer automorphism group of the Cuntz algebra 

      [OWP-2013-21] Conti, Roberto; Hong, Jeong Hee; Szymański, Wojciech (Mathematisches Forschungsinstitut Oberwolfach, 2013-10-29)
      We investigate the structure of the outer automorphism group of the Cuntz algebra and the closely related problem of conjugacy of MASAa in $\mathcal{O}_n$. In particular, we exhibit an uncountable family of MASAs, conjugate ...
    • Non-stationary multivariate subdivision: joint spectral radius and asymptotic similarity 

      [OWP-2013-20] Charina, Maria; Conti, Costanza; Guglielmi, Nicola; Protasov, Vladimir (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 ...
    • Local asymptotics for the area of random walk excursions 

      [OWP-2013-19] Denisov, Denis; Kolb, Martin; Wachtel, Vitali (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 ...
    • Near critical density irregular sampling in bernstein spaces 

      [OWP-2013-16] Olevskij, Aleksandr M.; Ulanovskii, Alexander (Mathematisches Forschungsinstitut Oberwolfach, 2013-07-23)
      We obtain sharp estimates for the sampling constants in Bernstein spaces when the density of the sampling set is near the critical value.
    • Grassmannian connection between three- and four-qubit observables, Mermin's contextualities and black holes 

      [OWP-2013-17] Lévay, Péter; Planat, Michel; Saniga, Metod (Mathematisches Forschungsinstitut Oberwolfach, 2013-07-23)
      We invoke some ideas from finite geometry to map bijectively 135 heptads of mutually commuting three-qubit observables into 135 symmetric four-qubit ones. After labeling the elements of the former set in terms of a ...
    • Linking and Closed Orbits 

      [OWP-2013-15] Suhr, Stefan; Zehmisch, Kai (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 ...
    • Solid extensions of the Cesàro operator on the Hardy space H2(D) 

      [OWP-2013-11] Curbera, Guillermo P.; Ricker, Werner J. (Mathematisches Forschungsinstitut Oberwolfach, 2013-04-23)
      We introduce and study the largest Banach space of analytic functions on the unit disc which is solid for the coefficient-wise order and to which the classical Ces`aro operator $\mathcal{C}:H^2 \to H^2$ can be continuously ...