Everywhere unbalanced configurations
Abstract
An old problem in discrete geometry, originating with Kupitz, asks whether there is a fixed natural number k such that every finite set of points in the plane has a line through at least two of its points where the number of points on either side of this line differ by at most k. We give a negative answer to a natural variant of this problem, showing that for every natural number k there exists a finite set of points in the plane together with a pseudoline arrangement such that each pseudoline contains at least two points and there is a pseudoline through any pair of points where the number of points on either side of each pseudoline differ by at least k. Moreover, we may find such a configuration with at most 2²ck points, which, by a result of Pinchasi, is best possible up to the value of the constant c.
Copyright and License
Funding
Research supported by NSF Awards DMS-2054452 and DMS-2348859. Research partially supported by an NUS Overseas Graduate Scholarship.
Additional details
Related works
- Is new version of
- Discussion Paper: arXiv:2308.02466 (arXiv)
Funding
- National Science Foundation
- DMS-2054452
- National Science Foundation
- DMS-2348859
- National University of Singapore
Dates
- Accepted
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2025-07-09
- Available
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2025-07-30Available online
- Available
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2025-07-30Version of record