Browsing 1 - Oberwolfach Preprints (OWP) by Title

Now showing items 330-349 of 399

    • Shape Theory and Extensions of C*-Algebras 

      [OWP-2010-16] Manujlov, Vladimir M.; Thomsen, Klaus (Mathematisches Forschungsinstitut Oberwolfach, 2010-03-16)
      Let A, A' be separable $C^*$-algebras, $B$ a stable $\sigma$-unital $C^*$-algebra. Our main result is the construction of the pairing $[[A', A]] \times Ext^{-1/2}(A,B) \to Ext^{-1/2}(A',B)$, where $[[A', A]]$ denotes the ...

    • Sharp constants in the classical weak form of the John-Nirenberg inequality 

      [OWP-2013-07] Vasyunin, Vasily; Volberg, Alexander (Mathematisches Forschungsinstitut Oberwolfach, 2013-03-14)
      The sharp constants in the classical John-Nirenberg inequality are found by using Bellman function approach.

    • Shock-avoiding Slicing Conditions: Tests and Calibrations 

      [OWP-2022-12] Baumgarte, Thomas W.; Hilditch, David (Mathematisches Forschungsinstitut Oberwolfach, 2022-07-19)
      While the 1+log slicing condition has been extremely successful in numerous numerical relativity simulations, it is also known to develop "gauge-shocks" in some examples. Alternative "shockavoiding" slicing conditions ...

    • Simple graded commutative algebras 

      [OWP-2009-12] Morier-Genoud, Sophie; Ovsienko, Valentin (Mathematisches Forschungsinstitut Oberwolfach, 2009-03-06)
      We study the notion of $\Gamma$-graded commutative algebra for an arbitrary abelian group $\Gamma$. The main examples are the Clifford algebras already treated in [2]. We prove that the Clifford algebras are the only ...

    • Simple vector bundles on plane degenerations of an elliptic curve 

      [OWP-2009-20] Bodnarchuk, Lesya; Drozd, Jurij A.; Greuel, Gert-Martin (Mathematisches Forschungsinstitut Oberwolfach, 2009-03-13)
      In 1957 Atiyah classified simple and indecomposable vector bundles on an elliptic curve. In this article we generalize his classification by describing the simple vector bundles on all reduced plane cubic curves. Our main ...

    • The Simplicial Complex of Brauer Pairs of a Finite Reductive Group 

      [OWP-2023-12] Rossi, Damiano (Mathematisches Forschungsinstitut Oberwolfach, 2023-07-17)
      In this paper we study the simplicial complex induced by the poset of Brauer pairs ordered by inclusion for the family of finite reductive groups. In the defining characteristic case the homotopy type of this simplicial ...

    • Simulation of Multibody Systems with Servo Constraints through Optimal Control 

      [OWP-2015-18] Altmann, Robert; Heiland, Jan (Mathematisches Forschungsinstitut Oberwolfach, 2015)
      We consider mechanical systems where the dynamics are partially constrained to prescribed trajectories. An example for such a system is a building crane with a load and the requirement that the load moves on a certain path. ...

    • Singer quadrangles 

      [OWP-2009-07] Winter, Stefaan de; Shult, Ernest E.; Thas, Koen (Mathematisches Forschungsinstitut Oberwolfach, 2009-03-01)

    • Singularities and Bifurcations of Pseudospherical Surfaces 

      [OWP-2020-08] Brander, David; Tari, Farid (Mathematisches Forschungsinstitut Oberwolfach, 2020-03-17)
      We study singularities and bifurcations of constant negative curvature surfaces in Euclidean 3-space via their association with Lorentzian harmonic maps. This preprint presents the basic results on this, the full proofs ...

    • Slowly oscillating wave solutions of a single species reaction-diffusion equation with delay 

      [OWP-2007-12] Trofimchuk, Elena; Tkachenko, Victor; Trofimchuk, Sergei I. (Mathematisches Forschungsinstitut Oberwolfach, 2007-03-28)
      We study positive bounded wave solutions $u(t, x) = \phi(\nu \cdot x+ct)$, $\phi(-\infty)=0$, of equation $u_t(t, x)=\delta u(t,x)−u(t,x) +g(u(t−h,x))$, $x \in \mathbb{R}^m$(*). It is supposed that Eq. (∗) has exactly two ...

    • 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 ...

    • Some Combinatorial Identities Related to Commuting Varieties and Hilbert Schemes 

      [OWP-2011-02] Bellamy, Gwyn; Ginzburg, Victor (Mathematisches Forschungsinstitut Oberwolfach, 2011)
      In this article we explore some of the combinatorial consequences of recent results relating the isospectral commuting variety and the Hilbert scheme of points in the plane.

    • Some Homological Properties of Borel Type Ideals 

      [OWP-2022-03] Herzog, Jürgen; Moradi, Somayeh; Rahimbeigi, Masoomeh; Zhu, Guangjun (Mathematisches Forschungsinstitut Oberwolfach, 2022-02-01)
      We study ideals of Borel type, including $k$-Borel ideals and $t$-spread Veronese ideals. We determine their free resolutions and their homological shift ideals. The multiplicity and the analytic spread of equigenerated ...

    • Some Results on Reducibility of Parabolic Induction for Classical Groups 

      [OWP-2017-09] Lapid, Erez; Tadić, Marko (Mathematisches Forschungsinstitut Oberwolfach, 2017-03-30)
      Given a (complex, smooth) irreducible representation $\pi$ of the general linear group over a non-archimedean local field and an irreducible supercuspidal representation $\sigma$ of a classical group, we show that ...

    • Some Results Related to Schiffer's Problem 

      [OWP-2018-18] Kawohl, Bernd; Lucia, Marcello (Mathematisches Forschungsinstitut Oberwolfach, 2018-08-16)
      We consider the following semilinear overdetermined problem on a two dimensional bounded or unbounded domain $\Omega$ with analytic boundary $\partial\Omega$ having at least one bounded connected component \begin{eqnarray*} ...

    • Space-Time Euler Discretization Schemes for the Stochastic 2D Navier-Stokes Equations 

      [OWP-2020-12] Bessaih, Hakima; Millet, Annie (Mathematisches Forschungsinstitut Oberwolfach, 2020-05-06)
      We prove that the implicit time Euler scheme coupled with finite elements space discretization for the 2D Navier-Stokes equations on the torus subject to a random perturbation converges in $L^2(\Omega)$, and describe the ...

    • Spatial-Skin Effect for a Spectral Problem with "Slightly Heavy" Concentrated Masses in a Thick Cascade Junction 

      [OWP-2012-10] Čečkin, Grigorij A.; Mel'nyk, Taras A. (Mathematisches Forschungsinstitut Oberwolfach, 2012-07-03)
      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 ...

    • Spectral Continuity for Aperiodic Quantum Systems II. Periodic Approximations in 1D 

      [OWP-2018-27] Beckus, Siegfried; Bellissard, Jean; De Nittis, Giuseppe (Mathematisches Forschungsinstitut Oberwolfach, 2018-12-17)
      The existence and construction of periodic approximations with convergent spectra is crucial in solid state physics for the spectral study of corresponding Schrödinger operators. In a forthcoming work [9] this task was ...

    • Spectral Sequences in Combinatorial Geometry: Cheeses, Inscribed Sets, and Borsuk-Ulam Type Theorems 

      [OWP-2010-08] Blagojevic, Pavle V. M.; Blagojevic, Aleksandra; Dimitrijevic McCleary, John (Mathematisches Forschungsinstitut Oberwolfach, 2010-03-12)
      Algebraic topological methods are especially suited to determining the nonexistence of continuous mappings satisfying certain properties. In combinatorial problems it is sometimes possible to define a mapping from a space ...

    • Spectral triples and finite summability on Cuntz-Krieger algebras 

      [OWP-2014-03] Goffeng, Magnus; Mesland, Bram (Mathematisches Forschungsinstitut Oberwolfach, 2014-05-13)
      We produce a variety of odd bounded Fredholm modules and odd spectral triples on Cuntz-Krieger algebras by means of realizing these algebras as "the algebra of functions on a non-commutative space" coming from a sub shift ...