From Word-Representable Graphs to Altered Tverberg-Type Theorems

Abstract Tverberg’s theorem states that a set with sufficiently many points in $${\mathbb {R}}^d$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mrow> <mml:mi>R</mml:mi> </mml:mrow> <mml:mi>d</mml:mi> </mml:msup> </mml:math> can always be partitioned into m parts such that the nerve (the intersection pattern) of the convex hulls of the parts form an $$(m-1)$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mo>(</mml:mo> <mml:mi>m</mml:mi> <mml:mo>-</mml:mo> <mml:mn>1</mml:mn> <mml:mo>)</mml:mo> </mml:mrow> </mml:math> -simplex. De Loera, Hogan, Oliveros, and Yang (2021) explored how other simplicial complexes can emerge as nerve complexes for sufficiently large point sets. In this paper, we establish a connection between the theory of word-representable graphs and a method for encoding the 1-skeletons of simplicial complexes to generate nerve complexes. Specifically, we demonstrate that every triangle-free 2-word-representable graph can be realized as a nerve complex in the plane, given sufficiently many points. Furthermore, for every bipartite graph, there exists a dimension d such that it can be represented as a nerve complex for sufficiently many points in $${\mathbb {R}}^d$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mrow> <mml:mi>R</mml:mi> </mml:mrow> <mml:mi>d</mml:mi> </mml:msup> </mml:math> .