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Let G(V,E) be a simple graph and let X subset of V. Two vertices u and v are said to be X-visible if there exists a shortest u,v-path P such that V(P) intersection X is a subset of {u, v}. A set X is called a mutual-visibility set of G if…

Combinatorics · Mathematics 2026-04-10 Tonny K B , Shikhi M

The \emph{general position problem} in graphs asks for a largest set of vertices in which no three lie on a common shortest path. The \emph{mutual-visibility problem} seeks a largest set of vertices such that every pair is connected by a…

Combinatorics · Mathematics 2026-01-28 Haritha S. , Ullas Chandran S.

Let $G$ be a graph and $X\subseteq V(G)$. Then, vertices $x$ and $y$ of $G$ are $X$-visible if there exists a shortest $u,v$-path where no internal vertices belong to $X$. The set $X$ is a mutual-visibility set of $G$ if every two vertices…

In this paper, connections between independent sets and the variety of mutual-visibility sets are studied. It is proved that every outer mutual-visibility set of a graph is independent if and only if the graph is distance edge-critical.…

Combinatorics · Mathematics 2026-03-02 Jing Tian , Csilla Bujtás , Sandi Klavžar

Mutual visibility in graphs requires pairs of vertices to be connected by shortest paths that avoid all other vertices of a prescribed set, a condition that is often overly restrictive. In this paper, we introduce a new variant, called…

Combinatorics · Mathematics 2026-03-04 Tonny K B , Shikhi M

Mutual visibility in graphs provides a framework for analysing how vertices can observe one another along shortest paths free of internal obstructions. The visibility polynomial, which enumerates mutual-visibility sets of all orders, has…

Combinatorics · Mathematics 2026-04-10 Tonny K B , Shikhi M

The general position problem for graphs asks for the largest number of vertices in a subset $S \subseteq V(G)$ of a graph $G$ such that for any $u,v \in S$ and any shortest $u,v$-path $P$ we have $S \cap V(P) = \{ u,v\} $, whereas the…

Combinatorics · Mathematics 2025-07-23 Ethan Shallcross , James Tuite , Aoise Evans , Aditi Krishnakumar , Sumaiyah Boshar

If $x\in V(G)$, then $S\subseteq V(G)\setminus\{x\}$ is an $x$-visibility set if for any $y\in S$ there exists a shortest $x,y$-path avoiding $S$. The $x$-visibility number $v_x(G)$ is the maximum cardinality of an $x$-visibility set, and…

Discrete Mathematics · Computer Science 2025-10-23 Dhanya Roy , Gabriele Di Stefano , Sandi Klavžar , Aparna Lakshmanan S

Mutual-visibility sets were motivated by visibility in distributed systems and social networks, and intertwine with several classical mathematical areas. Monotone properties of the variety of mutual-visibility sets, and restrictions of such…

Combinatorics · Mathematics 2025-12-10 Csilla Bujtás , Sandi Klavžar , Jing Tian

A subset $M$ of vertices in a graph $G$ is a mutual-visibility set if any two vertices $u$ and $v$ in $M$ ``see'' each other in $G$, that is, there exists a shortest $u,v$-path in $G$ that contains no elements of $M$ as internal vertices.…

Combinatorics · Mathematics 2026-03-30 Maria Axenovich , Dingyuan Liu

The concept of mutual visibility in a graph encodes combinatorial information about vertex subsets with prescribed visibility properties and serves as a useful algebraic invariant. In this paper, we derive algebraic conditions for the…

Combinatorics · Mathematics 2026-05-04 Tonny K B , Shikhi M

Let $X$ be a vertex subset of a graph $G$. Then $u, v\in V(G)$ are $X$-positionable if $V(P)\cap X \subseteq \{u,v\}$ holds for any shortest $u,v$-path $P$. If each two vertices from $X$ are $X$-positionable, then $X$ is a general position…

Combinatorics · Mathematics 2024-02-28 Jing Tian , Sandi Klavžar

The study of mutual visibility has traditionally focused on undirected graphs, asking for the maximum number of vertices that can communicate via shortest paths without intermediate interference from other set members. In this paper, we…

Combinatorics · Mathematics 2026-02-06 Vanja Stojanović

The concept of mutual-visibility (MV) has been extended in several directions. A vertex subset $S$ of a graph $G$ is a $k$-distance mutual-visibility ($k$DMV) set if for any two vertices in $S$, there is a geodesic between them of length at…

Combinatorics · Mathematics 2025-10-14 Saneesh Babu , Boštjan Brešar , Aparna Lakshmanan S , Babak Samadi

Networks are often modeled using graphs, and within this setting we introduce the notion of $k$-fault-tolerant mutual visibility. Informally, a set of vertices $X \subseteq V(G)$ in a graph $G$ is a $k$-fault-tolerant mutual-visibility set…

Combinatorics · Mathematics 2025-12-02 Serafino Cicerone , Gabriele Di Stefano , Sandi Klavžar , Gang Zhang

The mutual-visibility chromatic number of a graph $G$ is the smallest number of colors needed to color the vertices of $G$ such that each color class is a mutual-visibility set. In this paper, we prove that determining the mutual-visibility…

Combinatorics · Mathematics 2026-02-13 Saneesh Babu , Gabriele Di Stefano , Aparna Lakshmanan S

A point visibility graph is a graph induced by a set of points in the plane, where every vertex corresponds to a point, and two vertices are adjacent whenever the two corresponding points are visible from each other, that is, the open…

Computational Geometry · Computer Science 2019-02-05 Jean Cardinal , Udo Hoffmann

Visibility graph of a polygon corresponds to its internal diagonals and boundary edges. For each vertex on the boundary of the polygon, we have a vertex in this graph and if two vertices of the polygon see each other there is an edge…

Computational Geometry · Computer Science 2024-02-22 Hossein Boomari , Mojtaba Ostovari , Alireza Zarei

A new tur\'an-type problem on distances on graphs was introduced by Tyomkyn and Uzzell. In this paper, we focus on the case that the distance is two. We primely show that for any value of $n$, a graph on $n$ vertices without three vertices…

Combinatorics · Mathematics 2013-12-05 Xueliang Li , Jing Ma , Yongtang Shi , Jun Yue

In multiagent systems, effective coordination, coverage, and communication often rely on the concept of visibility between agents or nodes within the system. Graph-theoretically, for any subset $X$ of vertices of a graph $G$, two vertices…

Combinatorics · Mathematics 2025-09-03 Tonny K B , Shikhi M