English

Rainbow trapezoids with given area

Combinatorics 2026-03-17 v1

Abstract

A well-known result by Graham in Euclidean Ramsey Theory states that, for every positive real number AA, every coloring of the plane with finite number of colors contains a monochromatic triangle of area AA. We consider canonical versions of this result. We show that every 33-coloring of the plane integer lattice contains either a rainbow triangle of area 1/21/2 or a monochromatic rectangle of any given area whose sides are parallell to the axes. We also show that, under natural conditions, there are numbers AA and BB such that every coloring of the plane integer lattice contains either a monochromatic rectangle of area AA or a rainbow trapezoid of area BB. As usual, only vertex colors are considered: e.g., a monochromatic rectangle is a set of four points in the lattice which a) are the vertices of a rectangle and b) are assigned the same color.

Keywords

Cite

@article{arxiv.2603.13841,
  title  = {Rainbow trapezoids with given area},
  author = {Sukumar Das Adhikari and Tássio Naia and Oriol Serra},
  journal= {arXiv preprint arXiv:2603.13841},
  year   = {2026}
}

Comments

9 pages, 1 figure

R2 v1 2026-07-01T11:19:51.571Z