Rational normal curves as no-$(d+2)$-on-$Q$-quadric sets
Combinatorics
2025-11-06 v1 Algebraic Geometry
Abstract
For every , we construct a subset of size such that every affine hyperplane of intersects in at most points, and every hypersphere of intersects in at most points. This construction is the largest one currently known, and strongly builds on ideas of Dong, Xu, and also of Thiele. More generally, we prove that the role of hyperspheres can be replaced by -quadrics, i.e. by quadratic surfaces given by an equation whose degree two homogeneous part equals a fixed quadratic form . We formulate analogous statements in affine spaces over (finite) fields. Essentially, every construction is given by a suitable rational normal curve in a -dimensional projective space.
Cite
@article{arxiv.2511.03526,
title = {Rational normal curves as no-$(d+2)$-on-$Q$-quadric sets},
author = {Dávid R. Szabó},
journal= {arXiv preprint arXiv:2511.03526},
year = {2025}
}
Comments
First draft, comments welcome. 13 pages