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Related papers: On the quantum chromatic number of a graph

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The determination of the quantum chromatic number of graphs has attracted considerable attention recently. However, there are few families of graphs whose quantum chromatic numbers are determined. A notable exception is the family of…

Combinatorics · Mathematics 2025-12-02 Tao Luo , Yu Ning , Xiande Zhang

We make two contributions pertaining to the study of the quantum chromatic numbers of small graphs. Firstly, in an elegant paper, Man\v{c}inska and Roberson [\textit{Baltic Journal on Modern Computing}, 4(4), 846-859, 2016] gave an example…

Quantum Physics · Physics 2023-11-15 Olivier Lalonde

We construct a new graph on 120 vertices whose quantum and classical independence numbers are different. At the same time, we construct an infinite family of graphs whose quantum chromatic numbers are smaller than the classical chromatic…

Combinatorics · Mathematics 2024-02-09 Chris Godsil , Mariia Sobchuk

We study quantum analogs of graph colorings and chromatic number. Initially defined via an interactive protocol, quantum colorings can also be viewed as a natural operator relaxation of graph coloring. Since there is no known algorithm for…

Quantum Physics · Physics 2018-01-12 Laura Mančinska , David E. Roberson

The quantum chromatic number, $\chi_q(G)$, of a graph $G$ was originally defined as the minimal number of colors necessary in a quantum protocol in which two provers that cannot communicate with each other but share an entangled state can…

Combinatorics · Mathematics 2018-08-10 Pawel Wocjan , Clive Elphick

The clique chromatic number of a graph is the minimum number of colours needed to colour its vertices so that no inclusion-wise maximal clique which is not an isolated vertex is monochromatic. We show that every graph of maximum degree…

Combinatorics · Mathematics 2021-09-13 Gwenaël Joret , Piotr Micek , Bruce Reed , Michiel Smid

A clique colouring of a graph is a colouring of the vertices such that no maximal clique is monochromatic (ignoring isolated vertices). The least number of colours in such a colouring is the clique chromatic number. Given $n$ points $x_1,…

Combinatorics · Mathematics 2018-12-04 Colin McDiarmid , Dieter Mitsche , Pawel Pralat

The distinguishing chromatic number of a graph $G$ is the smallest number of colors needed to properly color the vertices of $G$ so that the trivial automorphism is the only symmetry of $G$ that preserves the coloring. We investigate the…

Combinatorics · Mathematics 2023-03-27 Michael D. Barrus , Jean Guillaume , Benjamin Lantz

The {\em chromatic gap} is the difference between the chromatic number and the clique number of a graph. Here we investigate $\gap(n)$, the maximum chromatic gap over graphs on $n$ vertices. Can the extremal graphs be explored? While…

Combinatorics · Mathematics 2020-12-01 András Gyárfás , András Sebõ , Nicolas Trotignon

As a fundamental metric for quantifying quantum advantage in non-local games, the quantum chromatic number reveals the power of entanglement in distributed tasks. In this paper, we investigate this parameter for $q$-ary Hamming graphs and a…

Combinatorics · Mathematics 2026-03-12 Xiwang Cao , Keqin Feng , Hexiang Huang , Yulin Yang , Zihao Zhang

The study of quantum chromatic numbers of graphs is a hot research topic in recent years. However, the infinite family of graphs with known quantum chromatic numbers are rare, as far as we know, the only known such graphs (except for…

Combinatorics · Mathematics 2024-12-31 Xiwang Cao , Keqin Feng , Ying-Ying Tan

The clique chromatic number of a graph is the smallest number of colors in a vertex coloring so that no maximal clique is monochromatic. In this paper, we determine the order of magnitude of the clique chromatic number of the random graph…

Combinatorics · Mathematics 2025-06-04 Manuel Fernandez , Lutz Warnke

We study graphs whose chromatic number is close to the order of the graph (the number of vertices). Both when the chromatic number is a constant multiple of the order and when the difference of the chromatic number and the order is a small…

Combinatorics · Mathematics 2011-07-14 Csaba Biró

A packing $k$-coloring of a graph $G$ is a partition of $V(G)$ into sets $V_1,\ldots,V_k$ such that for each $1\leq i\leq k$ the distance between any two distinct $x,y\in V_i$ is at least $i+1$. The packing chromatic number, $\chi_p(G)$, of…

Combinatorics · Mathematics 2017-03-31 József Balogh , Alexandr Kostochka , Xujun Liu

Although the chromatic number of a graph is not known in general, attempts have been made to find good bounds for the number. Here we prove that for a graph G with two forbidden subgraphs and maximum degree less than or equal to 2{\omega} -…

Combinatorics · Mathematics 2016-05-11 Medha Dhurandhar

The harmonious chromatic number of a graph $G$ is the minimum number of colors that can be assigned to the vertices of $G$ in a proper way such that any two distinct edges have different color pairs. This paper gives various results on…

A lambda colouring (or $L(2,1)-$colouring) of a graph is an assignment of non-negative integers (with minimum assignment $0$) to its vertices such that the adjacent vertices must receive integers at least two apart and vertices at distance…

Combinatorics · Mathematics 2019-01-07 Kaushik Majumder , Ushnish Sarkar

We discuss the minimal number of vertices in a graph with a large chromatic number such that each ball of a fixed radius in it has a small chromatic number. It is shown that for every graph $G$ on $\sim((n+rc)/(c+rc))^{r+1}$ vertices such…

Combinatorics · Mathematics 2014-02-03 Ilya I. Bogdanov

A cube-like graph is a Cayley graph for the elementary abelian group of order $2^n$. In studies of the chromatic number of cube-like graphs, the $k$th power of the $n$-dimensional hypercube, $Q_n^k$, is frequently considered. This coloring…

Combinatorics · Mathematics 2016-07-07 Janne I. Kokkala , Patric R. J. Östergård

We prove for k at most 10, that every graph of chromatic number k with a unique k-coloring admits a clique minor of order k.

Combinatorics · Mathematics 2020-02-20 Matthias Kriesell
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