The Origami flip graph of the $2\times n$ Miura-ori

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Christensen, Lumi, Hull, Thomas C., O'Neil, Emma, Pappano, Valentina, Ter-Saakov, Natalya, Yang, Kacey
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866908419672244224
author Christensen, Lumi
Hull, Thomas C.
O'Neil, Emma
Pappano, Valentina
Ter-Saakov, Natalya
Yang, Kacey
author_facet Christensen, Lumi
Hull, Thomas C.
O'Neil, Emma
Pappano, Valentina
Ter-Saakov, Natalya
Yang, Kacey
contents Given an origami crease pattern $C=(V,E)$, a straight-line planar graph embedded in a region of $\mathbb{R}^2$, we assign each crease to be either a mountain crease (which bends convexly) or a valley crease (which bends concavely), creating a mountain-valley (MV) assignment $μ:E\to\{-1,1\}$. An MV assignment $μ$ is locally valid if the faces around each vertex in $C$ can be folded flat under $μ$. In this paper, we investigate locally valid MV assignments of the Miura-ori, $M_{m,n}$, an $m\times n$ parallelogram tessellation used in numerous engineering applications. The origami flip graph $OFG(C)$ of $C$ is a graph whose vertices are locally valid MV assignments of $C$, and two vertices are adjacent if they differ by a face flip, an operation that swaps the MV-parity of every crease bordering a given face of $C$. We enumerate the number of vertices and edges in $OFG(M_{2,n})$ and prove several facts about the degrees of vertices in $OFG(M_{2,n})$. By finding recurrence relations, we show that the number of vertices of degree $d$ and $2n-a$ (for $0\leq a$) are both described by polynomials of particular degrees. We then prove that the diameter of $OFG(M_{2,n})$ is $\lceil \frac{n^2}{2}\rceil$ using techniques from 3-coloring reconfiguration graphs.
format Preprint
id arxiv_https___arxiv_org_abs_2506_19700
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle The Origami flip graph of the $2\times n$ Miura-ori
Christensen, Lumi
Hull, Thomas C.
O'Neil, Emma
Pappano, Valentina
Ter-Saakov, Natalya
Yang, Kacey
Combinatorics
Computational Geometry
05C90, 68U05
Given an origami crease pattern $C=(V,E)$, a straight-line planar graph embedded in a region of $\mathbb{R}^2$, we assign each crease to be either a mountain crease (which bends convexly) or a valley crease (which bends concavely), creating a mountain-valley (MV) assignment $μ:E\to\{-1,1\}$. An MV assignment $μ$ is locally valid if the faces around each vertex in $C$ can be folded flat under $μ$. In this paper, we investigate locally valid MV assignments of the Miura-ori, $M_{m,n}$, an $m\times n$ parallelogram tessellation used in numerous engineering applications. The origami flip graph $OFG(C)$ of $C$ is a graph whose vertices are locally valid MV assignments of $C$, and two vertices are adjacent if they differ by a face flip, an operation that swaps the MV-parity of every crease bordering a given face of $C$. We enumerate the number of vertices and edges in $OFG(M_{2,n})$ and prove several facts about the degrees of vertices in $OFG(M_{2,n})$. By finding recurrence relations, we show that the number of vertices of degree $d$ and $2n-a$ (for $0\leq a$) are both described by polynomials of particular degrees. We then prove that the diameter of $OFG(M_{2,n})$ is $\lceil \frac{n^2}{2}\rceil$ using techniques from 3-coloring reconfiguration graphs.
title The Origami flip graph of the $2\times n$ Miura-ori
topic Combinatorics
Computational Geometry
05C90, 68U05
url https://arxiv.org/abs/2506.19700