• 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 | ...
    • Classification of idempotent states on the compact quantum groups Uq(2), SUq(2) and SOq(3) 

      [OWP-2009-08] Franz, Uwe; Skalski, Adam; Tomatsu, Reiji (Mathematisches Forschungsinstitut Oberwolfach, 2009-03-02)
      We give a simple characterisation of those idempotent states on compact quantum groups which arise as Haar states on quantum subgroups, show that all idempotent states on quantum groups $U_q(2)$, $SU_q(2)$, and $SO_q(3) ...
    • Invariant Four-forms and Symmetric Pairs 

      [OWP-2012-03] Moroianu, Andrei; Semmelmann, Uwe (Mathematisches Forschungsinstitut Oberwolfach, 2012-04-24)
      We give criteria for real, complex and quaternionic representations to define $s$-representations, focusing on exceptional Lie algebras defined by spin representations. As applications, we obtain the classification of ...
    • Nondegenerate Invariant Symmetric Bilinear Forms on Simple Lie Superalgebras in Characteristic 2 

      [OWP-2020-02] Krutov, Andrey; Lebedev, Alexei; Leites, Dimitry; Shchepochkina, Irina (Mathematisches Forschungsinstitut Oberwolfach, 2020-02-04)
      As is well-known, the dimension of the space of non-degenerate invariant symmetric bilinear forms (NISes) on any simple finite-dimensional Lie algebra or Lie superalgebra is equal to at most 1 if the characteristic of the ...
    • Octonion Polynomials with Values in a Subalgebra 

      [OWP-2020-21] Chapman, Adam (Mathematisches Forschungsinstitut Oberwolfach, 2020-10-22)
      In this paper, we prove that given an octonion algebra $A$ over a field $F$, a subring $E \subseteq F$ and an octonion $E$-algebra $R$ inside $A$, the set $S$ of polynomials $f(x) \in A[x]$ satisfying $f(R) \subseteq R$ ...
    • On a Conjecture of Khoroshkin and Tolstoy 

      [OWP-2022-14] Appel, Andrea; Gautam, Sachin; Wendlandt, Curtis (Mathematisches Forschungsinstitut Oberwolfach, 2022-08-02)
      We prove a no-go theorem on the factorization of the lower triangular part in the Gaussian decomposition of the Yangian's universal $R$-matrix, yielding a negative answer to a conjecture of Khoroshkin and Tolstoy from ...
    • On commuting varieties of nilradicals of Borel subalgebras of reductive Lie algebras 

      [OWP-2012-14] Goodwin, Simon M.; Röhrle, Gerhard (Mathematisches Forschungsinstitut Oberwolfach, 2012-12-04)
      Let $G$ be a connected reductive algebraic group defined over an algebraically closed field $\mathbb{k}$ of characteristic zero. We consider the commuting variety $\mathcal{C}(\mathfrak{u})$ of the nilradical $\mathfrak{u}$ ...
    • On the Complement of the Richardson Orbit 

      [OWP-2010-09] Baur, Karin; Hille, Lutz (Mathematisches Forschungsinstitut Oberwolfach, 2010-03-13)
      We consider parabolic subgroups of a general algebraic group over an algebraically closed field $k$ whose Levi part has exactly $t$ factors. By a classical theorem of Richardson, the nilradical of a parabolic subgroup $P$ ...
    • On the Lie Algebra Structure of $HH^1(A)$ of a Finite-Dimensional Algebra A 

      [OWP-2019-10] Linckelmann, Markus; Rubio y Degrassi, Lleonard (Mathematisches Forschungsinstitut Oberwolfach, 2019-04-17)
      Let $A$ be a split finite-dimensional associative unital algebra over a field. The first main result of this note shows that if the Ext-quiver of $A$ is a simple directed graph, then $HH^1(A)$ is a solvable Lie algebra. ...
    • Plethysms, replicated Schur functions and series, with applications to vertex operators 

      [OWP-2010-12] Fauser, Bertfried; Jarvis, Peter D.; King, Ronald C. (Mathematisches Forschungsinstitut Oberwolfach, 2010-03-14)
      Specializations of Schur functions are exploited to define and evaluate the Schur functions $s_\lambda [\alpha X]$ and plethysms $s_\lambda [\alpha s_\nu(X))]$ for any $\alpha$-integer, real or complex. Plethysms are then ...
    • Positive Line Bundles Over the Irreducible Quantum Flag Manifolds 

      [OWP-2020-01] Díaz García, Fredy; Krutov, Andrey; Ó Buachalla, Réamonn; Somberg, Petr; Strung, Karen R. (Mathematisches Forschungsinstitut Oberwolfach, 2020-02-03)
      Noncommutative Kähler structures were recently introduced by the third author as a framework for studying noncommutative Kähler geometry on quantum homogeneous spaces. It was subsequently observed that the notion of a ...
    • Tensor Representations of q(∞) 

      [OWP-2016-09] Grantcharov, Dimitar; Serganova, Vera (Mathematisches Forschungsinstitut Oberwolfach, 2016-06-17)
      We introduce a symmetric monoidal category of modules over the direct limit queer superalgebra $\mathfrak{q}(\infty)$. The category can be defined in two equivalent ways with the aid of the large annihilator condition. ...