Filters

2007 - 200922010 - 20162

More filters

20194
Reset filters

Settings

Author: Burban, Igor × Start date: 1990 × Publisher: Oberwolfach : Mathematisches Forschungsinstitut Oberwolfach ×

Search Results

Now showing 1 - 4 of 4
  • Thumbnail Image
    Item
    Maximal Cohen-Macaulay modules over non-isolated surface singularities and matrix problems
    (Oberwolfach : Mathematisches Forschungsinstitut Oberwolfach, 2015) Burban, Igor; Drozd, Yuriy
    In this article we develop a new method to deal with maximal Cohen{ Macaulay modules over non{isolated surface singularities. In particular, we give a negative answer on an old question of Schreyer about surface singularities with only countably many indecomposable maximal Cohen{Macaulay modules. Next, we prove that the degenerate cusp singularities have tame Cohen{Macaulay representation type. Our approach is illustrated on the case of kJx; y; zK=(xyz) as well as several other rings. This study of maximal Cohen{Macaulay modules over non{isolated singularities leads to a new class of problems of linear algebra, which we call representations of decorated bunches of chains. We prove that these matrix problems have tame representation type and describe the underlying canonical forms.
  • Thumbnail Image
    Item
    Tilting on non-commutative rational projective curves
    (Oberwolfach : Mathematisches Forschungsinstitut Oberwolfach, 2009) Burban, Igor; Drozd, Yuriy
    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 bounded derived category of coherent sheaves on a reduced rational projective curve with only nodes and cusps as singularities, can be fully faithfully embedded into the right bounded derived category of the finite dimensional representations of a certain finite dimensional algebra of global dimension two. As an application of our approach we show that the dimension of the bounded derived category of coherent sheaves on a rational projective curve with only nodal or cuspidal singularities is at most two. In the case of the Kodaira cycles of projective lines, the corresponding tilted algebras belong to a well-known class of gentle algebras. We work out in details the tilting equivalence in the case of the Weierstrass nodal curve zy2=x3+x2z.
  • Thumbnail Image
    Item
    Vector bundles on degenerations of elliptic curves and Yang-Baxter equations
    (Oberwolfach : Mathematisches Forschungsinstitut Oberwolfach, 2007) Burban, Igor; Kreussler, Bernd
    In this paper we introduce the notion of a gemetric associative r-matrix attached to a genus one fibration with a section and irreducible fibres. It allows us to study degenerations of solutions of the classical Yang-Baxter equation using the approach of Polishchuk. We also calculate certain solutions of the classical, quantum and associative Yang-Baxter equations obtained from moduli spaces of (semi-)stable vector bundles on Weierstraß cubic curves.
  • Thumbnail Image
    Item
    Fourier-Mukai transform on Weierstrass cubics and commuting cifferential operators
    (Oberwolfach : Mathematisches Forschungsinstitut Oberwolfach, 2016) Burban, Igor; Zheglov, Alexander
    In this article, we describe the spectral sheaves of algebras of commuting differential operators of genus one and rank two with singular spectral curve, solving a problem posed by Previato and Wilson. We also classify all indecomposable semi-stable sheaves of slope one and ranks two or three on a cuspidal Weierstraß cubic.