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Related papers: On 1-Planar Graphs with Bounded Cop-Number

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Mohar recently adapted the classical game of Cops and Robber from graphs to metric spaces, thereby unifying previously studied pursuit-evasion games. He conjectured that finitely many cops can win on any compact geodesic metric space, and…

Combinatorics · Mathematics 2023-09-08 Agelos Georgakopoulos

We introduce and study quantized versions of Cop and Robber game. We achieve this by using graph-preserving quantum operations, which are the quantum analogues of stochastic operations preserving the graph. We provide the tight bound for…

Quantum Physics · Physics 2017-11-29 Adam Glos , Jarosław Adam Miszczak

We explore a variant of the game of Cops and Robber introduced by Bonato et al.~where the robber is invisible unless outside the common neighbourhood of the cops. The hyperopic cop number is analogous to the cop number and we investigate…

Combinatorics · Mathematics 2021-07-16 Nancy E. Clarke , Stephen Finbow , Margaret-Ellen Messinger , Amanda Porter

We show that the 1-planar slope number of 3-connected cubic 1-planar graphs is at most 4 when edges are drawn as polygonal curves with at most 1 bend each. This bound is obtained by drawings whose vertex and crossing resolution is at least…

Computational Geometry · Computer Science 2018-08-28 Philipp Kindermann , Fabrizio Montecchiani , Lena Schlipf , André Schulz

Define a boundary point of a graph which is embedded in the Euclidean plane a vertex which is incident to only one edge. In this paper we consider graphs which are embedded in the Euclidean plane with a finite number of boundary points. The…

Combinatorics · Mathematics 2015-01-12 Yashar Memarian

We prove that the cop number of any $2K_2$-free graph is at most 2, proving a conjecture of Sivaraman and Testa. We also show that the upper bound of $3$ on the cop number of $2K_1+K_2$-free (co-diamond--free) graphs is best possible.

Combinatorics · Mathematics 2025-10-29 Jérémie Turcotte

A cop tries to capture a robber in a topological space $X$ being unable to see him. For which spaces $X$ does the cop have a strategy which allows him to capture the robber independently of his efforts to escape? In other words, when is…

General Topology · Mathematics 2022-10-24 Jonathan A. Barmak

A track layout of a graph consists of a vertex coloring and a total order of each color class, such that no two edges cross between any two color classes. The track number of a graph is the minimum number of colors required by a track…

Discrete Mathematics · Computer Science 2020-07-24 Sergey Pupyrev

There is a graph reduction system so that every optimal 1-planar graph can be reduced to an irreducible extended wheel graph, provided the reductions are applied such that the given graph class is preserved. A graph is optimal 1-planar if…

Computational Geometry · Computer Science 2016-10-28 Franz J. Brandenburg

A graph with n vertices is 1-planar if it can be drawn in the plane such that each edge is crossed at most once, and is optimal if it has the maximum of 4n-8 edges. We show that optimal 1-planar graphs can be recognized in linear time. Our…

Discrete Mathematics · Computer Science 2018-01-25 Franz J. Brandenburg

Let $B$ be a set of Eulerian subgraphs of a graph $G$. We say $B$ forms a $k$-basis if it is a minimum set that generates the cycle space of $G$, and any edge of $G$ lies in at most $k$ members of $B$. The basis number of a graph $G$,…

Combinatorics · Mathematics 2024-12-25 Saman Bazargani , Therese Biedl , Prosenjit Bose , Anil Maheshwari , Babak Miraftab

We propose a definition of generalized Cops and Robbers games where there are two players, the Pursuer and the Evader, who each move via prescribed rules. If the Pursuer can ensure that the game enters into a fixed set of final positions,…

Combinatorics · Mathematics 2017-04-20 Anthony Bonato , Gary MacGillivray

We show that if $\{G_n\}_{n\geq 1}$ is a sequence of graphs of order $n$ with bounded maximum degree and isoperimetric function $\Phi(G_n,n^{1-\alpha})$ bounded away from $0$ as $n\rightarrow \infty$, then the cop number of $G_n$ is at most…

Combinatorics · Mathematics 2024-02-12 Alexander Clow

We establish a lower bound for the cop number of graphs of high girth in terms of the minimum degree, and more generally, in terms of a certain growth condition. We show, in particular, that the cop number of any graph with girth $g$ and…

Combinatorics · Mathematics 2020-05-25 Peter Bradshaw , Seyyed Aliasghar Hosseini , Bojan Mohar , Ladislav Stacho

In this paper we analyze and model three open problems posed by Harris, Insko, Prieto-Langarica, Stoisavljevic, and Sullivan in 2020 concerning the tipsy cop and robber game on graphs. The three different scenarios we model account for…

Combinatorics · Mathematics 2021-03-01 Viktoriya Bardenova , Vincent Ciarcia , Erik Insko

We show that the cop number of directed and undirected Cayley graphs on abelian groups has an upper bound of the form of $O(\sqrt{n})$, where $n$ is the number of vertices, by introducing a refined inductive method. With our method, we…

Combinatorics · Mathematics 2025-10-29 Peter Bradshaw , Seyyed Aliasghar Hosseini , Jérémie Turcotte

In previous work, we introduced median decompositions, a generalisation of tree decompositions where a graph can be modelled after any median graph, along with a hierarchy of $i$-medianwidth parameters $(mw_i)_{i\geq 1}$ starting from…

Combinatorics · Mathematics 2016-03-23 Konstantinos Stavropoulos

We study the 1-planar, quasi-planar, and fan-planar crossing number in comparison to the (unrestricted) crossing number of graphs. We prove that there are $n$-vertex 1-planar (quasi-planar, fan-planar) graphs such that any 1-planar…

Computational Geometry · Computer Science 2019-09-10 Markus Chimani , Philipp Kindermann , Fabrizio Montecchiani , Pavel Valtr

We consider a variation of Cops and Robber, introduced in [D. Cox and A. Sanaei, The damage number of a graph, [Aust. J. of Comb. 75(1) (2019) 1-16] where vertices visited by a robber are considered damaged and a single cop aims to minimize…

Combinatorics · Mathematics 2024-12-19 Melissa A. Huggan , Margaret-Ellen Messinger , Amanda Porter

We investigate various pursuit-evasion parameters on latin square graphs, including the cop number, metric dimension, and localization number. The cop number of latin square graphs is studied, and for $k$-MOLS$(n),$ bounds for the cop…

Combinatorics · Mathematics 2021-10-01 Shreya Ahirwar , Anthony Bonato , Leanna Gittins , Alice Huang , Trent G. Marbach , Tomer Zaidman