2 citations · 6 across the 8 of their papers we have counts for
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The Chain Matrix of Bouquets of Geometric Lattices and its Determinant
Winfried Hochstättler, Sophia Keip
This work builds on Varchenko et al's introduction of bilinear forms for hyperplane arrangements, where the determinant of the associated matrices factorizes into simple components…
A classification of Mengerian -uniform hypergraphs derived from graphs
Winfried Hochstättler, Mehrdad Nasernejad
In this paper, we give a classification of all Mengerian -uniform hypergraphs derived from graphs.
The signed Varchenko Determinant for Complexes of Oriented Matroids
Winfried Hochstättler, Sophia Keip, Kolja Knauer
We generalize the (signed) Varchenko matrix of a hyperplane arrangement to complexes of oriented matroids and show that its determinant has a nice factorization. This extends previ…
Oriented cobicircular matroids are
Santiago Guzmán-Pro, Winfried Hochstättler
Colourings and flows are well-known dual notions in Graph Theory. In turn, the definition of flows in graphs naturally extends to flows in oriented matroids. So, the colour-flow du…
Kirchberger's Theorem for Complexes of Oriented Matroids
Winfried Hochstättler, Sophia Keip, Kolja Knauer
The separation theorem of Kirchberger can be proven using a combination of Farkas' Lemma and Caratheodory's Theorem. Since those theorems are at the heart of oriented matroids, we…
The Neighborhood Polynomial of Chordal Graphs
Helena Bergold, Winfried Hochstättler, Uwe Mayer
We study the neighborhood polynomial and the complexity of its computation for chordal graphs. The neighborhood polynomial of a graph is the generating function of subsets of its v…
On the Complexity of Digraph Colourings and Vertex Arboricity
Winfried Hochstättler, Felix Schröder, Raphael Steiner
It has been shown by Bokal et al. that deciding 2-colourability of digraphs is an NP-complete problem. This result was later on extended by Feder et al. to prove that deciding whet…