Signe Lundqvist

collaborators

4 papers

math.CO2026

Sparsity greedoids and pebble game algorithms for posets

Signe Lundqvist, Tovohery Randrianarisoa, Klara Stokes +1

We generalise a sparsity condition for hypergraphs and show a result relating sparseness of hypergraphs to the decomposition of a modified incidence graph into edge-disjoint forest…

math.CO2025

The pure condition for incidence geometries

Daniel Irving Bernstein, Signe Lundqvist

The space of \emph{parallel redrawings} of an incidence geometry $(P, H, I)$ with an assigned set of normals is the set of points and hyperplanes in $R^{d}$ satisfying the inc…

math.CO2025

Counting for rigidity under projective transformations in the plane

Leah Wrenn Berman, Signe Lundqvist, Bernd Schulze +4

Let $P$ be a set of points and $L$ a set of lines in the (extended) Euclidean plane, and $I \subseteq P \times L$ , where $i = (p, l) \in I$ means that point $p$ and line $l$ are incid…

math.MG2025

Projective rigidity of point-line configurations in the plane

Leah Berman, Signe Lundqvist, Bernd Schulze +4

In this paper, we establish a general setup for studying incidence-preserving motions of projective geometric configurations of points and lines via a "projective rigidity matrix".…