EXPOSITIO

A home for expository scholarship

Expositio is a repository for expository papers in a wide range of academic disciplines, supporting preprints, revisions, optional peer review, saved papers, and overlay journals.

6 Papers in view

What is Expositio?

A public repository for expository academic papers, with an integrated scholarly record.

Expositio is a place to read and cite expository work. Papers are published as stable, citable records, while remaining connected to later versions, editorial decisions, and related context.

Some papers are early drafts; others have been peer reviewed or formally published. Each paper remains readable on its own, while preserving the history behind it.

The result is both a reading room and a record: a place to browse by field, read papers in stable form, and follow their development over time.

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Combinatorics

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Mathematics Combinatorics
Domain: Mathematics × Branch: Combinatorics ×

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Preprint
v2

The representations of the Symmetric Groups S_n carry a very rich combinatorial structure. In particular, their representations have connections to seemingly unrelated problems, including to symmetric polynomials and the theory of Young Tableau. We demonstrate some classical res…

Mathematics / Combinatorics
Mathematics > Combinatorics > Combinatorial aspects of representation theory Primary
v1

This paper gives an expository introduction to arithmetic progressions in Ramsey theory and additive combinatorics. We begin with the language of colorings, using small examples to illustrate how simple coloring rules can force surprisingly rigid structure. The main result discu…

Mathematics / Combinatorics
Mathematics > Combinatorics > Ramsey theory Primary
v1

Sidorenko's conjecture predicts that the homomorphism density of a bipartite graph H in a host graph G satisfies t_H(G) ≥ t_{K_2}(G)^|E(H)|. We introduce the conjecture through homomorphism densities, prove the finite-host inequality for P_3, C_4, and the complete bipartite grap…

Mathematics / Combinatorics
Mathematics > Combinatorics > Density (toughness, etc.) Primary

Expositio paper

How Close Can a Chromatic Root Get to One?

Arnav Dhiman

Preprint
v1

In this paper we show that the chromatic function $P(G,t)$ is always a polynomial. We then ask a simple question: where does this polynomial equal zero? Tutte showed that two stretches of the real line, $(-\infty,0)$ and $(0,1)$, can never contain a root. Jackson showed in 1993 …

Mathematics / Combinatorics
Mathematics > Combinatorics > Coloring of graphs and hypergraphs Primary
Preprint
v1

Combinatorial game theory and coding theory appear to be completely separate fields at first glance. However, they share a profound connection through structures known as lexicographic codes, or lexicodes. First introduced by Conway and Sloane in 1986, lexicodes are generated by…

Mathematics / Combinatorics
Mathematics > Combinatorics > Research exposition (monographs, survey articles) pertaining to combinatorics Primary

Expositio paper

An introduction to matroid theory

Kaiser Travis Chan

Preprint
v1

In this paper, we explore matroids, which generalize properties of linear independence of vectors and cycles in graphs. We investigate properties and operations on matroids, then we look at how we can represent matroids using matrices.

Mathematics / Combinatorics
Mathematics > Combinatorics > Combinatorial aspects of matroids and geometric lattices Primary