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Related papers: Estimating quantum chromatic numbers

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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

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

We investigate the notion of quantum chromatic number of a graph, which is the minimal number of colours necessary in a protocol in which two separated provers can convince an interrogator with certainty that they have a colouring of the…

Quantum Physics · Physics 2011-11-09 Peter J. Cameron , Ashley Montanaro , Michael W. Newman , Simone Severini , Andreas Winter

The dichromatic number of a graph $G$ is the maximum integer $k$ such that there exists an orientation of the edges of $G$ such that for every partition of the vertices into fewer than $k$ parts, at least one of the parts must contain a…

Combinatorics · Mathematics 2022-09-20 Bojan Mohar , Hehui Wu

Quantum graphs are an operator space generalization of classical graphs that have emerged in different branches of mathematics including operator theory, non-commutative topology and quantum information theory. In this paper, we obtain…

Operator Algebras · Mathematics 2021-12-06 Priyanga Ganesan

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

First, I introduce quantum graph theory. I also discuss a known lower bound on the independence numbers and derive from it an upper bound on the chromatic numbers of quantum graphs. Then, I construct a family of quantum graphs that can be…

Quantum Physics · Physics 2014-12-01 Steven Lu

The Additive Coloring Problem is a variation of the Coloring Problem where labels of $\{1,\ldots,k\}$ are assigned to the vertices of a graph $G$ so that the sum of labels over the neighborhood of each vertex is a proper coloring of $G$.…

Discrete Mathematics · Computer Science 2020-02-28 Daniel Severin

The Lovasz theta function provides a lower bound for the chromatic number of finite graphs based on the solution of a semidefinite program. In this paper we generalize it so that it gives a lower bound for the measurable chromatic number of…

Combinatorics · Mathematics 2009-11-21 Christine Bachoc , Gabriele Nebe , Fernando Mario de Oliveira Filho , Frank Vallentin

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

This paper serves as the first extension of the topic of dominator colorings of graphs to the setting of digraphs. We establish the dominator chromatic number over all possible orientations of paths and cycles. In this endeavor we discover…

Combinatorics · Mathematics 2019-02-21 Michael Cary

The quantum chromatic number, a generalization of the chromatic number, was first defined in relation to the non-local quantum coloring game. We generalize the former by defining the quantum $k$-distance chromatic number $\chi_{kq}(G)$ of a…

Combinatorics · Mathematics 2025-03-05 Aida Abiad , Benjamin Jany

The {\em acyclic chromatic number} of a graph is the least number of colors needed to properly color its vertices so that none of its cycles has only two colors. The {\em acyclic chromatic index} is the analogous graph parameter for edge…

Combinatorics · Mathematics 2024-10-15 Lefteris Kirousis , John Livieratos

A packing $k$-coloring is a natural variation on the standard notion of graph $k$-coloring, where vertices are assigned numbers from $\{1, \ldots, k\}$, and any two vertices assigned a common color $c \in \{1, \ldots, k\}$ need to be at a…

Discrete Mathematics · Computer Science 2025-06-13 Bernardo Subercaseaux , Marijn J. H. Heule

In this paper we further explore the recently discovered connection by Bj\"{o}rklund and Kaski [STOC 2024] and Pratt [STOC 2024] between the asymptotic rank conjecture of Strassen [Progr. Math. 1994] and the three-way partitioning problem.…

Data Structures and Algorithms · Computer Science 2024-12-09 Andreas Björklund , Radu Curticapean , Thore Husfeldt , Petteri Kaski , Kevin Pratt

We investigate vector chromatic number, Lovasz theta of the complement, and quantum chromatic number from the perspective of graph homomorphisms. We prove an analog of Sabidussi's theorem for each of these parameters, i.e. that for each of…

Combinatorics · Mathematics 2013-05-27 Chris Godsil , David Roberson , Robert Šámal , Simone Severini

In this paper we study bipartite quantum correlations using techniques from tracial noncommutative polynomial optimization. We construct a hierarchy of semidefinite programming lower bounds on the minimal entanglement dimension of a…

Optimization and Control · Mathematics 2018-01-10 Sander Gribling , David de Laat , Monique Laurent

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

DP-coloring (also called correspondence coloring) is a well-studied generalization of list coloring introduced by Dvo\v{r}\'{a}k and Postle in 2015. The following sharp bound on the DP-chromatic number of the Cartesian product of graphs $G$…

Combinatorics · Mathematics 2025-07-30 Hemanshu Kaul , Jeffrey A. Mudrock , Gunjan Sharma

A proper vertex colouring of a graph is \emph{nested} if the vertices of each of its colour classes can be ordered by inclusion of their open neighbourhoods. Through a relation to partially ordered sets, we show that the nested chromatic…

Combinatorics · Mathematics 2013-06-04 David Cook
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