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An independent set in a graph G is a set of pairwise non-adjacent vertices. A graph $G$ is bipartite if its vertex set can be partitioned into two independent sets. In the Odd Cycle Transversal problem, the input is a graph $G$ along with a…

Data Structures and Algorithms · Computer Science 2024-02-20 Akanksha Agrawal , Paloma T. Lima , Daniel Lokshtanov , Pawel Rzążewski , Saket Saurabh , Roohani Sharma

The \emph{Antimagic Graph Conjecture} asserts that every connected graph $G = (V, E)$ except $K_2$ admits an edge labeling such that each label $1, 2, ..., |E|$ is used exactly once and the sums of the labels on all edges incident with a…

Combinatorics · Mathematics 2013-10-07 Matthias Beck , Michael Jackanich

In the present paper, exterior algebraic shifting and symmetric algebraic shifting of bipartite graphs and chordal graphs are studied. First, we will determine the symmetric algebraic shifted graph of complete bipartite graphs. It turns out…

Combinatorics · Mathematics 2008-04-11 Satoshi Murai

Lov\'{a}sz conjectured that every connected vertex-transitive graph contains a hamilton path in 1970. First we reveal the structure of connected vertex-transitive graphs with an odd number of vertices. Then we prove that every connected…

Combinatorics · Mathematics 2024-07-31 Misa Nakanishi

A graph is almost bipartite if it contains exactly one odd cycle, and it is Konig-Egervary if the sum of the independence number and the matching number equals the order of the graph. We introduce the class of Bipartite-Almost Bipartite…

Combinatorics · Mathematics 2026-03-12 Kevin Pereyra

The mirror (or bipartite complement) mir(B) of a bipartite graph B=(X,Y,E) has the same color classes X and Y as B, and two vertices x in X and y in Y are adjacent in mir(B) if and only if xy is not in E. A bipartite graph is chordal…

Discrete Mathematics · Computer Science 2013-09-24 Anne Berry , Andreas Brandstädt , Konrad Engel

We present an algorithm for determining whether a bipartite graph $G$ is 2-chordal (formerly doubly chordal bipartite). At its core this algorithm is an extension of the existing efficient algorithm for determining whether a graph is…

Combinatorics · Mathematics 2021-04-13 Austin Alderete

Oriented graph complexes, in which graphs are not allowed to have oriented cycles, govern for example the quantization of Lie bialgebras and infinite dimensional deformation quantization. It is shown that the oriented graph complex GC^or_n…

Quantum Algebra · Mathematics 2015-06-16 Thomas Willwacher

In "Bipartite minors" [Journal of Combinatorial Theory, Series B, 2016], Chudnovsky et al. introduced the bipartite minor relation, a quasi-order on the class of bipartite graphs somewhat analogous the minor relation on general graphs and…

Combinatorics · Mathematics 2026-03-05 Therese Biedl , Dinis Vitorino

A graph is an opposition graph, respectively, a coalition graph, if it admits an acyclic orientation which puts the two end-edges of every chordless 4-vertex path in opposition, respectively, in the same direction. Opposition and coalition…

Discrete Mathematics · Computer Science 2015-07-03 Van Bang Le , Thomas Podelleck

Each finite and connected bipartite graph induces a finite collection of non-isomorphic dessins d'enfants, that is, $2$-cell embeddings of it into some closed orientable surface. We describe an algorithm to compute all these dessins…

Combinatorics · Mathematics 2017-08-24 Ruben A. Hidalgo

An orientation of a graph $G$ is proper if any two adjacent vertices have different indegrees. The proper orientation number $\overrightarrow{\chi}(G)$ of a graph $G$ is the minimum of the maximum indegree, taken over all proper…

The classes of odd graphs $O_n$ and middle levels graphs $B_n$ form one parameter subclasses of the Kneser graphs and bipartite Kneser graphs respectively. In particular both classes are vertex transitive while resisting definitive…

Combinatorics · Mathematics 2016-11-22 Timothy J. Frye

Bipartite best match graphs (BMG) and their generalizations arise in mathematical phylogenetics as combinatorial models describing evolutionary relationships among related genes in a pair of species. In this work, we characterize the class…

Combinatorics · Mathematics 2025-11-06 Annachiara Korchmaros , Guillaume E. Scholz , Peter F. Stadler

A classification is given of all the countable homogeneous ordered bipartite graphs.

Combinatorics · Mathematics 2024-01-17 J. K. Truss

Bidirected graphs generalize directed and undirected graphs in that edges are oriented locally at every node. The natural notion of the degree of a node that takes into account (local) orientations is that of net-degree. In this paper, we…

Combinatorics · Mathematics 2017-04-11 Laura Gellert , Raman Sanyal

A bipartite graph $H$ is said to have Sidorenko's property if the probability that the uniform random mapping from $V(H)$ to the vertex set of any graph $G$ is a homomorphism is at least the product over all edges in $H$ of the probability…

Combinatorics · Mathematics 2018-07-11 David Conlon , Jeong Han Kim , Choongbum Lee , Joonkyung Lee

Let $G$ be a group. The directed endomorphism graph, $\dend(G)$ of $G$ is a directed graph with vertex set $G$ and there is a directed edge from the vertex $a$ to the vertex $b$ if $a \neq b$ and there exists an endomorphism on $G$ mapping…

Group Theory · Mathematics 2025-11-20 Midhuna V Ajith , Peter J Cameron , Mainak Ghosh , Aparna Lakshmanan S

In this paper we consider bi-Cohen-Macaulay graphs, and give a complete classification of such graphs in the case they are bipartite or chordal. General bi-Cohen-Macaulay graphs are classified up to separation. The inseparable…

Commutative Algebra · Mathematics 2015-08-31 Jürgen Herzog , Ahad Rahimi

Topological drawings are natural representations of graphs in the plane, where vertices are represented by points, and edges by curves connecting the points. Topological drawings of complete graphs and of complete bipartite graphs have been…

Computational Geometry · Computer Science 2017-02-10 Jean Cardinal , Stefan Felsner