• Amorphic Complexity of Group Actions with Applications to Quasicrystals 

      [OWP-2021-03] Fuhrmann, Gabriel; Gröger, Maik; Jäger, Tobias; Kwietniak, Dominik (Mathematisches Forschungsinstitut Oberwolfach, 2021-02-02)
      In this article, we define amorphic complexity for actions of locally compact $\sigma$-compact amenable groups on compact metric spaces. Amorphic complexity, originally introduced for $\mathbb Z$-actions, is a topological ...
    • Analysis and Simulation of a New Multi-Component Two-Phase Flow Model with Phase Transitions and Chemical Reactions 

      [OWP-2017-08] Hantke, Maren; Müller, Siegfried (Mathematisches Forschungsinstitut Oberwolfach, 2017-03-15)
      A class-II model for multi-component mixtures recently introduced in D. Bothe, W. Dreyer, Continuum thermodynamics of chemically reacting fluid mixtures, Acta Mech., 226 (2015), 1757–1805 is investigated for simple mixtures. ...
    • Analytic Structure in Fibers 

      [OWP-2016-13] Aron, Richard M.; Falcó, Javier; García, Domingo; Maestre, Manuel (Mathematisches Forschungsinstitut Oberwolfach, 2016-08-17)
      Let $B_X$ be the open unit ball of a complex Banach space $X$, and let $\mathcal{H}^\infty(B_X)$ and $\mathcal{A}_u(B_X)$ be, respectively, the algebra of bounded holomorphic functions on $B_X$ and the subalgebra of uniformly ...
    • Analytic Varieties with Finite Volume Amoebas are Algebraic 

      [OWP-2011-33] Madani, Farid; Nisse, Mounir (Mathematisches Forschungsinstitut Oberwolfach, 2011)
      In this paper, we study the amoeba volume of a given $k$-dimensional generic analytic variety $V$ of the complex algebraic torus $(C^*)^n$. When $n>=2k$, we show that $V$ is algebraic if and only if the volume of its amoeba ...
    • Applications of BV Type Spaces 

      [OWP-2019-04] Appell, Jürgen; Bugajewska, Daria; Kasprzak, Piotr; Merentes, Nelson; Reinwand, Simon; Sánchez, José Luis (Mathematisches Forschungsinstitut Oberwolfach, 2019-02-13)
    • Applications of Nijenhuis Geometry III: Frobenius Pencils and Compatible Non-Homogeneous Poisson Structures 

      [OWP-2022-01] Bolsinov, Alexey V.; Konyaev, Andrey Yu.; Matveev, Vladimir S. (Mathematisches Forschungsinstitut Oberwolfach, 2022-01-20)
      We consider multicomponent local Poisson structures of the form $\mathcal P_3 + \mathcal P_1$, under the assumption that the third order term $\mathcal P_3$ is Darboux-Poisson and non-degenerate, and study the Poisson ...
    • Approximation of discrete functions and size of spectrum 

      [OWP-2009-17] Olevskij, Aleksandr M.; Ulanovskii, Alexander (Mathematisches Forschungsinstitut Oberwolfach, 2009-03-11)
      Let $\Lambda \subset \mathbb{R}$ be a uniformly discrete sequence and $S \subset \mathbb{R}$ a compact set. We prove that if there exists a bounded sequence of functions in Paley-Wiener space $PW_s$, which approximates ...
    • Arm Exponent for the Gaussian Free Field on Metric Graphs in Intermediate Dimensions 

      [OWP-2024-01] Drewitz, Alexander; Prévost, Alexis; Rodriguez, Pierre-François (Mathematisches Forschungsinstitut Oberwolfach, 2024-01-08)
      We investigate the bond percolation model on transient weighted graphs ${G}$ induced by the excursion sets of the Gaussian free field on the corresponding metric graph. We assume that balls in ${G}$ have polynomial volume ...
    • Asymptotic behavior of the eigenvalues and eigenfunctions to a spectral problem in thick cascade junction with concentrated masses 

      [OWP-2011-12] Chechkin, Gregory A.; Mel'nyk, Taras A. (Mathematisches Forschungsinstitut Oberwolfach, 2011-05-14)
      The asymptotic behavior (as $\varepsilon \to 0$) of eigenvalues and eigenfunctions of a boundaryvalue problem for the Laplace operator in a thick cascade junction with concentrated masses is investigated. This cascade ...
    • Automatic Differentiation for ML-Familiy Languages: Correctness via Logical Relations 

      [OWP-2023-07] Lucatelli Nunes, Fernando; Vákár, Matthijs (Mathematisches Forschungsinstitut Oberwolfach, 2023-06-19)
    • Averages of Shifted Convolutions of d3(n) 

      [OWP-2011-11] Baier, Stephan; Browning, Tim; Marasingha, Gihan; Zhao, Liangyi (Mathematisches Forschungsinstitut Oberwolfach, 2011-05-13)
      We investigate the first and second moments of shifted convolutions of the generalised divisor function $d_3(n)$.
    • The Becker-Gottlieb Transfer: a Geometric Description 

      [OWP-2019-13] Wang, Yi-Sheng (Mathematisches Forschungsinstitut Oberwolfach, 2019-05-14)
      In this note, we examine geometric aspects of the Becker-Gottlieb transfer in terms of the Umkehr and index maps, and rework some classic index theorems, using the cohomological formulae of the Becker-Gottlieb transfer. ...
    • The Berry-Keating Operator on a Lattice 

      [OWP-2016-23] Bolte, Jens; Egger, Sebastian; Keppeler, Stefan (Mathematisches Forschungsinstitut Oberwolfach, 2016-11-17)
      We construct and study a version of the Berry-Keating operator with a built-in truncation of the phase space, which we choose to be a two-dimensional torus. The operator is a Weyl quantisation of the classical Hamiltonian ...
    • Birational Rowmotion on a Rectangle over a Noncommutative Ring 

      [OWP-2022-17] Grinberg, Darij; Roby, Tom (Mathematisches Forschungsinstitut Oberwolfach, 2022-09-20)
      We extend the periodicity of birational rowmotion for rectangular posets to the case when the base field is replaced by a noncommutative ring (under appropriate conditions). This resolves a conjecture from 2014. The proof ...
    • Bochner-Riesz Means at the Critical Index: Weighted and Sparse Bounds 

      [OWP-2023-16] Beltran, David; Roos, Joris; Seeger, Andreas (Mathematisches Forschungsinstitut Oberwolfach, 2023-11-27)
      We consider Bochner-Riesz means on weighted $L^p$ spaces, at the critical index $\lambda(p)=d(\frac 1p-\frac 12)-\frac 12$. For every $A_1$-weight we obtain an extension of Vargas' weak type $(1,1)$ inequality in some range ...
    • Boundary Conditions for Scalar Curvature 

      [OWP-2021-01] Bär, Christian; Hanke, Bernhard (Mathematisches Forschungsinstitut Oberwolfach, 2021-01-04)
      Based on the Atiyah-Patodi-Singer index formula, we construct an obstruction to positive scalar curvature metrics with mean convex boundaries on spin manifolds of infinite $K$-area. We also characterize the extremal case. ...
    • Boundary Representations of Operator Spaces, and Compact Rectangular Matrix Convex Sets 

      [OWP-2016-24] Fuller, Adam H.; Hartz, Michael; Lupini, Martino (Mathematisches Forschungsinstitut Oberwolfach, 2016-12-13)
      We initiate the study of matrix convexity for operator spaces. We define the notion of compact rectangular matrix convex set, and prove the natural analogs of the Krein-Milman and the bipolar theorems in this context. We ...
    • Bounded Weight Modules for Basic Classical Lie Superalgebras at Infinity 

      [OWP-2022-09] Grantcharov, Dimitar; Penkov, Ivan; Serganova, Vera (Mathematisches Forschungsinstitut Oberwolfach, 2022-05-30)
      We classify simple bounded weight modules over the complex simple Lie superalgebras $\mathfrak{sl}(\infty |\infty)$ and $\mathfrak{osp} (m | 2n)$, when at least one of $m$ and $n$ equals $\infty$. For $\mathfrak{osp} (m | ...
    • Braid equivalences and the L-moves 

      [OWP-2011-20] Lambropoulou, Sofia (Mathematisches Forschungsinstitut Oberwolfach, 2011-05-19)
      In this survey paper we present the L-moves between braids and how they can adapt and serve for establishing and proving braid equivalence theorems for various diagrammatic settings, such as for classical knots, for knots ...
    • Braidoids 

      [OWP-2020-17] Gügümcü, Neslihan; Lambropoulou, Sofia (Mathematisches Forschungsinstitut Oberwolfach, 2020-09-03)
      Braidoids generalize the classical braids and form a counterpart theory to the theory of planar knotoids, just as the theory of braids does for the theory of knots. In this paper, we introduce the notion of braidoids in ...