"Hyperplane Arrangements over the Ring of Integers Modulo N." by Ehiareshan James Obeahon

Graduation Term

2023

Degree Name

Master of Science (MS)

Department

Department of Mathematics

Committee Chair

Sunil K. Chebolu

Committee Member

Papa A. Sissokho

Abstract

Let V be a finite vector space of dimension n over the field K. A hyperplane in V is an n − 1 dimensional subspace of V defined by an equation of the form∑ni=1 aixi = 0, ai ∈ K, (x1, ..., xn) ∈ V . A hyperplane arrangement is any finite collectionof hyperplanes. This work focuses on some hyperplanes arrangements such as the braid and the graphical arrangement {xi − xj = 0 : 1 ≤ i < j ≤ n}, the shi arrangement {xi − xj = 1 : 1 ≤ i < j ≤ n}, the threshold arrangement {xi + xj = 0 : 1 ≤ i < j ≤ n}, and the complete arrangement {∑i∈S xi = 0 : S ⊆ [n]}. The graphical arrangement is a subarrangement of the threshold arrangement. Chapter 1 gives an introductory overview of the entire work, the significance of hyperplane arrangements, and their interconnections.Chapter 2 presents some of the important definitions and the general theory underlying hyperplane arrangements. Chapter 2 also introduces what we would call the most important concept in the study of hyperplane arrangement, which is the characteristic polynomial. Every hyperplane arrangement(or simply arrangement) can be identified by a unique characteristic polynomial. Chapter 3 covers the braid, graphical, and Shi arrangement, and application to graph coloring, while Chapter 4 explores the threshold arrangement, and how it relates to threshold graphs. There is a bijection between the set of threshold graphs on n vertices and the set of regions of the boxed threshold arrangement. Finally, chapter 5 gives an introduction to the complete arrangement.

KEYWORDS: Threshold Arrangement, Characteristic Polynomial, Finite Field Method.

Access Type

Thesis-Open Access

DOI

https://doi.org/10.30707/ETD2023.20240124055107872704.999988

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