• Abstract Bivariant Cuntz Semigroups 

      [OWP-2017-04] Antoine, Ramon; Perera, Francesc; Thiel, Hannes (Mathematisches Forschungsinstitut Oberwolfach, 2017-02-13)
      We show that abstract Cuntz semigroups form a closed symmetric monoidal category. Thus, given Cuntz semigroups S and T, there is another Cuntz semigroup ((S,T)) playing the role of morphisms from S to T. Applied ...
    • Counting Curves on Toric Surfaces Tropical Geometry & the Fock Space 

      [OWP-2017-18] Cavalieri, Renzo; Johnson, Paul; Markwig, Hannah; Ranganathan, Dhruv (Mathematisches Forschungsinstitut Oberwolfach, 2017-07-17)
      We study the stationary descendant Gromov–Witten theory of toric surfaces by combining and extending a range of techniques – tropical curves, floor diagrams, and Fock spaces. A correspondence theorem is established between ...
    • Linear Syzygies, Hyperbolic Coxeter Groups and Regularity 

      [OWP-2017-15] Constantinescu, Alexandru; Kahle, Thomas; Varbaro, Matteo (Mathematisches Forschungsinstitut Oberwolfach, 2017-05-24)
      We build a new bridge between geometric group theory and commutative algebra by showing that the virtual cohomological dimension of a Coxeter group is essentially the regularity of the Stanley–Reisner ring of its nerve. ...
    • On Unipotent Radicals of Pseudo-Reductive Groups 

      [OWP-2017-12] Bate, Michael; Martin, Benjamin; Röhrle, Gerhard; Stewart, David I. (Mathematisches Forschungsinstitut Oberwolfach, 2017-04-27)
      We establish some results on the structure of the geometric unipotent radicals of pseudo-reductive k-groups. In particular, let k be a purely inseparable field extension of k of degree pe and let G denote the ...
    • On Vietoris-Rips Complexes of Ellipses 

      [OWP-2017-11] Adamaszek, Michal; Adams, Henry; Reddy, Samadwara (Mathematisches Forschungsinstitut Oberwolfach, 2017-04-25)
      For X a metric space and r>0 a scale parameter, the Vietoris–Rips complex VR<(X;r) (resp. VR(X;r)) has X as its vertex set, and a finite subset σX as a simplex whenever the diameter of ...