Happy ending: An empty hexagon in every set of 30 points

MJH Heule, M Scheucher - … Conference on Tools and Algorithms for the …, 2024 - Springer
Satisfiability solving has been used to tackle a range of long-standing open math problems
in recent years. We add another success by solving a geometry problem that originated a …

An improved lower bound on the number of pseudoline arrangements

FC Kühnast, J Dallant, S Felsner… - arxiv preprint arxiv …, 2024 - arxiv.org
Arrangements of pseudolines are classic objects in discrete and computational geometry.
They have been studied with increasing intensity since their introduction almost 100 years …

Inserting one edge into a simple drawing is hard

A Arroyo, F Klute, I Parada, B Vogtenhuber… - Discrete & …, 2023 - Springer
Abstract A simple drawing D (G) of a graph G is one where each pair of edges share at most
one point: either a common endpoint or a proper crossing. An edge e in the complement of …

New lower bounds for the number of pseudoline arrangements

A Dumitrescu, R Mandal - Proceedings of the Thirtieth Annual ACM-SIAM …, 2019 - SIAM
Arrangements of lines and pseudolines are fundamental objects in discrete and
computational geometry. They also appear in other areas of computer science, such as the …

[HTML][HTML] Two disjoint 5-holes in point sets

M Scheucher - Computational Geometry, 2020 - Elsevier
Given a set of points S⊆ R 2, a subset X⊆ S with| X|= k is called k-gon if all points of X lie on
the boundary of the convex hull of X, and k-hole if, in addition, no point of S∖ X lies in the …

Flip graph connectivity for arrangements of pseudolines and pseudocircles

YA Radtke, S Felsner, J Obenaus, S Roch… - Proceedings of the 2024 …, 2024 - SIAM
Flip graphs of combinatorial and geometric objects are at the heart of many deep structural
insights and connections between different branches of discrete mathematics and computer …

Arrangements of pseudocircles: On circularizability

S Felsner, M Scheucher - Discrete & Computational Geometry, 2020 - Springer
An arrangement of pseudocircles is a collection of simple closed curves on the sphere or in
the plane such that any two of the curves are either disjoint or intersect in exactly two …

Minimizing convex functions with rational minimizers

H Jiang - Journal of the ACM, 2022 - dl.acm.org
Given a separation oracle SO for a convex function f defined on ℝn that has an integral
minimizer inside a box with radius R, we show how to find an exact minimizer of f using at …

Convex hulls of random order types

X Goaoc, E Welzl - Journal of the ACM, 2023 - dl.acm.org
We establish the following two main results on order types of points in general position in the
plane (realizable simple planar order types, realizable uniform acyclic oriented matroids of …

Topological drawings of complete bipartite graphs

J Cardinal, S Felsner - International Symposium on Graph Drawing and …, 2016 - Springer
Topological drawings are natural representations of graphs in the plane, where vertices are
represented by points, and edges by curves connecting the points. We consider a natural …