English
Related papers

Related papers: Lower Bounds for the Cop Number When the Robber is…

200 papers

We consider a variation of the Cops and Robber game where the cops can only see the robber when the distance between them is at most a fixed parameter $\ell$. We consider the basic consequences of this definition for some simple graph…

Discrete Mathematics · Computer Science 2017-08-25 N. E. Clarke , D. Cox , C. Duffy , D. Dyer , S. Fitzpatrick , M. E. Messinger

In 2019, Sivaraman conjectured that every $P_k$-free graph has cop number at most $k-3$. In the same year, Liu proved this conjecture for $(P_k,\text{claw})$-free graphs. Recently Chudnovsky, Norin, Seymour, and Turcotte proved this…

Combinatorics · Mathematics 2025-09-16 Alexander Clow , Erin Meger

The deduction game is a variation of the game of cops and robber on graphs in which searchers must capture an invisible evader in at most one move. Searchers know each others' initial locations, but can only communicate if they are on the…

Combinatorics · Mathematics 2024-12-24 Andrea Burgess , Danny Dyer , Mozhgan Farahani

The traditional game of cops and robbers is played on undirected graph. Recently, the same game played on directed graph is getting attention by more and more people. We knew that if we forbid some subgraph we can bound the cop number of…

Combinatorics · Mathematics 2020-01-29 Mingrui Liu

We study a variation of the classical pursuit-evasion game of Cops and Robbers in which agents are required to move to an adjacent vertex on every turn. We explore how the minimum number of cops needed to catch the robber can change when…

Combinatorics · Mathematics 2018-08-22 Ilya Gromovikov , William B. Kinnersley , Ben Seamone

We consider the game of Cops and Robber played on the Cartesian product of two trees. Assuming the players play perfectly, it is shown that if there are two cops in the game, then the length of the game (known as the 2-capture time of the…

Combinatorics · Mathematics 2010-11-02 Abbas Mehrabian

We present an algorithm of time complexity $O(kn^{k+2})$ deciding whether a graph $G$ on $n$ vertices is $k$-copwin. The fastest algorithm thus far had time complexity $O(n^{2k+2})$.

Data Structures and Algorithms · Computer Science 2022-06-16 Jan Petr , Julien Portier , Leo Versteegen

We bound expected capture time and throttling number for the cop versus gambler game on a connected graph with $n$ vertices, a variant of the cop versus robber game that is played in darkness, where the adversary hops between vertices using…

Discrete Mathematics · Computer Science 2019-06-03 Jesse Geneson , Carl Joshua Quines , Espen Slettnes , Shen-Fu Tsai

Meyniel's conjecture is one of the deepest open problems on the cop number of a graph. It states that for a connected graph $G$ of order $n,$ $c(G) = O(\sqrt{n}).$ While largely ignored for over 20 years, the conjecture is receiving…

Combinatorics · Mathematics 2013-08-16 William Baird , Anthony Bonato

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

In this paper we study the concurrent cops and robber (CCCR) game. CCCR follows the same rules as the classical, turn-based game, except for the fact that the players move simultaneously. The cops' goal is to capture the robber and the…

Discrete Mathematics · Computer Science 2015-06-12 Georgios Konstantinidis , Athanasios Kehagias

We consider the Cops and Robber pursuit-evasion game when the edge-set of the graph is allowed to change in time, possibly at every round. Specifically, the game is played on an infinite periodic sequence $\mathcal{G} = (G_0, \dots,…

Discrete Mathematics · Computer Science 2024-10-31 Jean-Lou De Carufel , Paola Flocchini , Nicola Santoro , Frédéric Simard

Cop-width and flip-width are new families of graph parameters introduced by Toru\'nczyk (2023) that generalise treewidth, degeneracy, generalised colouring numbers, clique-width and twin-width. In this paper, we bound the cop-width and…

Combinatorics · Mathematics 2025-05-14 Robert Hickingbotham

It is known that the class of all graphs not containing a graph $H$ as an induced subgraph is cop-bounded if and only if $H$ is a forest whose every component is a path. In this study, we characterize all sets $\mathscr{H}$ of graphs with…

Combinatorics · Mathematics 2020-07-14 Masood Masjoody , Ladislav Stacho

In the game of Cops and Robbers, the capture time of a graph is the minimum number of moves needed by the cops to capture the robber, assuming optimal play. We prove that the capture time of the $n$-dimensional hypercube is $\Theta (n\ln…

Combinatorics · Mathematics 2013-08-16 Anthony Bonato , William B. Kinnersley , P. Gordinowicz , P. Pralat

The fastest algorithms for edge coloring run in time $2^m n^{O(1)}$, where $m$ and $n$ are the number of edges and vertices of the input graph, respectively. For dense graphs, this bound becomes $2^{\Theta(n^2)}$. This is a somewhat unique…

Data Structures and Algorithms · Computer Science 2018-04-10 Łukasz Kowalik , Arkadiusz Socała

We study the stopping times of gossip algorithms for network coding. We analyze algebraic gossip (i.e., random linear coding) and consider three gossip algorithms for information spreading Pull, Push, and Exchange. The stopping time of…

Information Theory · Computer Science 2012-08-28 Michael Borokhovich , Chen Avin , Zvi Lotker

We study relations between diameter $D(G)$, domination number $\gamma(G)$, independence number $\alpha(G)$ and cop number $c(G)$ of a connected graph $G$, showing (i.) $c(G) \leq \alpha(G)-\lfloor \frac{D(G)-3}{2} \rfloor$, and (ii.) $c(G)…

Combinatorics · Mathematics 2023-03-21 Jan Petr , Julien Portier , Leo Versteegen

The game of Cops and Robber is traditionally played on a finite graph. The purpose of this note is to introduce and analyze the game that is played on an arbitrary geodesic space. The game is defined in such a way that it preserves the…

Combinatorics · Mathematics 2021-12-07 Bojan Mohar

We obtain some new upper bounds on the maximum number $f(n)$ of edges in $n$-vertex graphs without containing cycles of length four. This leads to an asymptotically optimal bound on $f(n)$ for a broad range of integers $n$ as well as a…

Combinatorics · Mathematics 2021-10-13 Jie Ma , Tianchi Yang