• 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 ...
    • Criteria for Algebraicity of Analytic Functions 

      [OWP-2018-25] Bochnak, Jacek; Gwoździewicz, Janusz; Kucharz, Wojciech (Mathematisches Forschungsinstitut Oberwolfach, 2018-11-12)
      We consider functions defined on an open subset of a nonsingular, either real or complex, algebraic set. We give criteria for an analytic function to be a Nash (resp. regular, resp. polynomial) function. Our criteria depend ...
    • Demailly’s Notion of Algebraic Hyperbolicity: Geometricity, Boundedness, Moduli of Maps 

      [OWP-2018-20] Javanpeykar, Ariyan; Kamenova, Ljudmila (Mathematisches Forschungsinstitut Oberwolfach, 2018-10-08)
      Demailly's conjecture, which is a consequence of the Green-Griffiths-Lang conjecture on varieties of general type, states that an algebraically hyperbolic complex projective variety is Kobayashi hyperbolic. Our aim is to ...
    • Freeness of Multi-Reflection Arrangements via Primitive Vector Fields 

      [OWP-2017-10] Hoge, Torsten; Mano, Toshiyuki; Röhrle, Gerhard; Stump, Christian (Mathematisches Forschungsinstitut Oberwolfach, 2017-04-20)
      In 2002, Terao showed that every reflection multi-arrangement of a real reflection group with constant multiplicity is free by providing a basis of the module of derivations. We first generalize Terao's result to ...
    • A Function Algebra Providing New Mergelyan Type Theorems in Several Complex Variables 

      [OWP-2019-02] Falcó, Javier; Gauthier, Paul Montpetit; Manolaki, Myrto; Nestoridis, Vassili (Mathematisches Forschungsinstitut Oberwolfach, 2019-02-11)
      For compact sets $K\subset \mathbb C^{d}$, we introduce a subalgebra $A_{D}(K)$ of $A(K)$, which allows us to obtain Mergelyan type theorems for products of planar compact sets as well as for graphs of functions.
    • Global Variants of Hartogs' Theorem 

      [OWP-2018-24] Bochnak, Jacek; Kucharz, Wojciech (Mathematisches Forschungsinstitut Oberwolfach, 2018-11-06)
      Hartogs' theorem asserts that a separately holomorphic function, defined on an open subset of $\mathbb{C}^n$, is holomorphic in all the variables. We prove a global variant of this theorem for functions defined on an open ...
    • Gradient Canyons, Concentration of Curvature, and Lipschitz Invariants 

      [OWP-2017-35] Paunescu, Laurentiu; Tibăr, Mihai-Marius (Mathematisches Forschungsinstitut Oberwolfach, 2017-12-13)
      We find new bi-Lipschitz invariants of holomorphic functions of two variables by using the gradient canyons and by combining analytic and geometric viewpoints on the concentration of curvature.
    • Inductive Freeness of Ziegler’s Canonical Multiderivations for Reflection Arrangements 

      [OWP-2017-14] Hoge, Torsten; Röhrle, Gerhard (Mathematisches Forschungsinstitut Oberwolfach, 2017-04-30)
      Let $A$ be a free hyperplane arrangement. In 1989, Ziegler showed that the restriction $A''$ of $A$ to any hyperplane endowed with the natural multiplicity is then a free multiarrangement. We initiate a study of the stronger ...
    • Milnor fibre homology via deformation 

      [OWP-2015-22] Siersma, Dirk; Tibăr, Mihai-Marius (Mathematisches Forschungsinstitut Oberwolfach, 2015)
      In case of one-dimensional singular locus, we use deformations in order toget refined information about the Betti numbers of the Milnor fibre.
    • A new counting function for the zeros of holomorphic curves 

      [OWP-2009-25] Anderson, J. M.; Hinkkanen, Aimo (Mathematisches Forschungsinstitut Oberwolfach, 2009-03-18)
      Let $f_1,..., f_p$ be entire functions that do not all vanish at any point, so that $(f_1,..., f_p)$ is a holomorphic curve in $\mathbb{CP}^{p-1}$. We introduce a new and more careful notion of counting the order of the ...
    • Non-integrated defect relation for meromorphic maps of complete Kähler manifolds into a projective variety intersecting hypersurfaces 

      [OWP-2010-19] Tran, Van Tan; Vu, Van Truong (Mathematisches Forschungsinstitut Oberwolfach, 2010)
      In 1985, Fujimoto established a non-integrated defect relation for meromorphic maps of complete Kähler manifolds into the complex projective space intersecting hyperplanes in general position. In this paper, we generalize ...
    • Numerical Invariants and Moduli Spaces for Line Arrangements 

      [OWP-2017-02] Dimca, Alexandru; Ibadula, Denis; Măcinic, Daniela Anca (Mathematisches Forschungsinstitut Oberwolfach, 2017-02-01)
      Using several numerical invariants, we study a partition of the space of line arrangements in the complex projective plane, given by the intersection lattice types. We offer also a new characterization of the free plane ...
    • On the Directionally Newton-non-degenerate Singularities of Complex Hypersurfaces 

      [OWP-2008-16] Kerner, Dmitry (Mathematisches Forschungsinstitut Oberwolfach, 2008)
      We introduce a minimal generalization of Newton-non-degenerate singularities of hypersurfaces. Roughly speaking, an isolated hypersurface singularity is called directionally Newton-non-degenerate if the local embedded ...
    • On the geometry of regular maps from a quasi-projective surface to a curve 

      [OWP-2013-03] Parameswaran, A. J.; Tibăr, Mihai-Marius (Mathematisches Forschungsinstitut Oberwolfach, 2013-03-14)
      We explore consequences of the triviality of the monodromy group, using the condition of purity of the mixed Hodge structure on the cohomology of the surface X.
    • On the non-analyticity locus of an arc-analytic function 

      [OWP-2009-03] Kurdyka, Krzysztof; Parusinski, Adam (Mathematisches Forschungsinstitut Oberwolfach, 2009-02-21)
      A function is called arc-analytic if it is real analytic on each real analytic arc. In real analytic geometry there are many examples of arc-analytic functions that are not real analytic. Arc analytic functions appear ...
    • On the δ=const Collisions of Singularities of Complex Plane Curves 

      [OWP-2008-15] Kerner, Dmitry (Mathematisches Forschungsinstitut Oberwolfach, 2008)
      We study a specific class of deformations of curve singularities: the case when the singular point splits to several ones, such that the total $\delta$ invariant is preserved. These are also known as equi-normalizable or ...
    • Rational Approximation on Products of Planar Domains 

      [OWP-2016-05] Aron, Richard M.; Gauthier, Paul Montpetit; Maestre, Manuel; Nestoridis, Vassili; Falcó, Javier (Mathematisches Forschungsinstitut Oberwolfach, 2016-06-17)
      We consider $A(\Omega)$, the Banach space of functions $f$ from $ \overline{\Omega}=\prod_{i \in I} \overline{U_i}$ to $\mathbb{C}$ that are continuous with respect to the product topology and separately holomorphic, where ...
    • Real Analyticity is Concentrated in Dimension 2 

      [OWP-2018-23] Bochnak, Jacek; Kucharz, Wojciech (Mathematisches Forschungsinstitut Oberwolfach, 2018-11-05)
      We prove that a real-valued function on a real analytic manifold is analytic whenever all its restrictions to $2$-dimensional analytic submanifolds are analytic functions. We also obtain analogous results in the framework ...
    • Second Main Theorems and Unicity of Meromorphic Mappings with Moving Hypersurfaces 

      [OWP-2011-38] Si, Duc Quang (Mathematisches Forschungsinstitut Oberwolfach, 2011)
      In this article, we establish some new second main theorems for meromorphic mappings of $\mathbf{C}^m$ into $\mathbf{P}^n(\mathbf{C})$ and moving hypersurfaces with truncated counting functions. As an application, we prove ...
    • Spherical Arc-Length as a Global Conformal Parameter for Analytic Curves in the Riemann Sphere 

      [OWP-2016-21] Gauthier, Paul Montpetit; Nestoridis, Vassili; Papadopoulos, Athanase (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 ...