7 papers
Symmetric polyhedral scenes and parallel redrawings
Signe Lundqvist, Bernd Schulze, Klara Stokes
Liftings and parallel redrawings are classical topics in applied discrete geometry, concerned respectively with vertically lifting a -picture -- a realisation of a vertex-hy…
The pure condition for incidence geometries
Daniel Irving Bernstein, Signe Lundqvist
The space of \emph{parallel redrawings} of an incidence geometry with an assigned set of normals is the set of points and hyperplanes in satisfying the inc…
Counting for rigidity under projective transformations in the plane
Leah Wrenn Berman, Signe Lundqvist, Bernd Schulze +4
Let be a set of points and a set of lines in the (extended) Euclidean plane, and , where means that point and line are incid…
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".…
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…
When is a planar rod configuration infinitesimally rigid?
Signe Lundqvist, Klara Stokes, Lars-Daniel Öhman
We provide a way of determining the infinitesimal rigidity of rod configurations realizing a rank two incidence geometry in the Euclidean plane. We model each rod with a cone over…
Exploring the infinitesimal rigidity of planar configurations of points and rods
Signe Lundqvist, Klara Stokes, Lars-Daniel Öhman
This article is concerned with the rigidity properties of geometric realizations of incidence geometries of rank two as points and lines in the Euclidean plane; we care about the d…