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19922026
most citedObservation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHC

10.9k citations

Showing 2018 · math.COShow all

18 papers · 2 filters

math.CO2018★ 1 cited

On the structure of (claw,bull)-free graphs

Sebastián González Hermosillo de la Maza, Yifan Jing, Masood Masjoody

In this research, we determine the structure of (claw, bull)-free graphs. We show that every connected (claw, bull)-free graph is either an expansion of a path, an expansion of a c…

math.CO2018★ 2 cited

A rainbow version of Mantel's Theorem

Ron Aharoni, Matt DeVos, Sebastián González Hermosillo de la Maza +2

Mantel's Theorem asserts that a simple vertex graph with more than edges has a triangle (three mutually adjacent vertices). Here we consider a rainbow variant…

math.CO2018

Traversal with Enumeration of Geometric Graphs in Bounded Space

Sahand Khakabimamaghani, Masood Masjoody, Ladislav Stacho

In this paper, we provide an algorithm for traversing geometric graphs which visits all vertices, and reports every vertex and edge exactly once. To achieve this, we combine a give…

math.CO2018

The structure of graphs with no K_{3,3} immersion

Matt DeVos, Mahdieh Malekian

The Kuratowski-Wagner Theorem asserts that a graph is planar if and only if it does not have either or as a minor. Using this Wagner obtained a precise description…

math.CO2018★ 1 cited

Constructing Geometric Graphs of Cop Number Three

Seyyed Aliasghar Hosseini, Masood Masjoody, Ladislav Stacho

The game of cops and robbers is a pursuit game on graphs where a set of agents, called the cops try to get to the same position of another agent, called the robber. Cops and robber…

math.CO2018

Which graphs occur as -graphs?

Matt DeVos, Adam Dyck, Jonathan Jedwab +1

The -graph of a graph is the graph whose vertices are labelled by the minimum dominating sets of , in which two vertices are adjacent when their corresponding minimum dom…

math.CO2018★ 2 cited

Triangle-free subgraphs with large fractional chromatic number

Bojan Mohar, Hehui Wu

It is well known that for any integers and , there is a graph with chromatic number at least and girth at least . In 1960's, Erdős and Hajnal conjectured that for any…

math.CO2018★ 1 cited

A golden ratio inequality for vertex degrees of graphs

Fiachra Knox, Bojan Mohar, David R. Wood

Motivated by the study of the crossing number of graphs, it is shown that, for trees, the sum of the products of the degrees of the end-vertices of all edges has an upper bound in…

math.CO2018★ 2 cited

Fractional chromatic number of a random subgraph

Bojan Mohar, Hehui Wu

It is well known that a random subgraph of the complete graph has chromatic number w.h.p. Boris Bukh asked whether the same holds for a random subgraph of any $…

math.CO2018★ 2 cited

On walks avoiding a quadrant

Kilian Raschel, Amélie Trotignon

Two-dimensional (random) walks in cones are very natural both in combinatorics and probability theory: they are interesting for themselves and also because they are strongly relate…

math.CO2018★ 8 cited

The Algebraic Connectivity of a Graph and its Complement

B. Afshari, S. Akbari, M. J. Moghaddamzadeh +1

For a graph , let denote its second smallest Laplacian eigenvalue. It was conjectured that , where is the complement of $…

math.CO2018★ 2 cited

A new structure for difference matrices over abelian -groups

Koen van Greevenbroek, Jonathan Jedwab

A difference matrix over a group is a discrete structure that is intimately related to many other combinatorial designs, including mutually orthogonal Latin squares, orthogonal arr…

math.CO2018

Short rainbow cycles in graphs and matroids

Matt DeVos, Matthew Drescher, Daryl Funk +5

Let be a simple -vertex graph and be a colouring of with colours, where each colour class has size at least . We prove that contains a rainbow cycl…

math.CO2018

The Chromatic Number of Finite Group Cayley Tables

Luis Goddyn, Kevin Halasz, E. S. Mahmoodian

The chromatic number of a latin square , denoted , is the minimum number of partial transversals needed to cover all of its cells. It has been conjectured that every latin…

math.CO2018

The genus of complete 3-uniform hypergraphs

Yifan Jing, Bojan Mohar

In 1968, Ringel and Youngs confirmed the last open case of the Heawood Conjecture by determining the genus of every complete graph . In this paper, we investigate the minimum…

math.CO2018★ 2 cited

3d positive lattice walks and spherical triangles

B Bogosel, V Perrollaz, K. Raschel +1

In this paper we explore the asymptotic enumeration of three-dimensional excursions confined to the positive octant. As shown in [29], both the exponential growth and the critical…

math.CO2018

A counterexample to Las Vergnas' strong map conjecture on realizable oriented matroids

Pei Wu

The Las Vergnas' strong map conjecture, states that any strong map of oriented matroids can be factored into extensions and contractions.…

math.CO2018★ 4 cited

Structure and generation of crossing-critical graphs

Zdeněk Dvořák, Petr Hliněný, Bojan Mohar

We study -crossing-critical graphs, which are the minimal graphs that require at least edge-crossings when drawn in the plane. For there are only two such graphs witho…