Now showing items 1-5 of 5

• #### Abstract Bivariant Cuntz Semigroups ﻿

[OWP-2017-04] (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] (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] (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] (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 $p^e$ and let $G$ denote the ...
• #### On Vietoris-Rips Complexes of Ellipses ﻿

[OWP-2017-11] (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 $\sigma \subseteq X$ as a simplex whenever the diameter of ...