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Related papers: Some classes of graphs that are not PCGs

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A graph $G=(V,E)$ is called a pairwise compatibility graph (PCG) if there exists an edge-weighted tree $T$ and two non-negative real numbers $d_{min}$ and $d_{max}$ such that each leaf $u$ of $T$ corresponds to a vertex $u \in V$ and there…

Combinatorics · Mathematics 2022-05-17 Sheikh Azizul Hakim , Bishal Basak Papan , Md. Saidur Rahman

A graph G=(V,E) is a pairwise compatibility graph (PCG) if there exists an edge-weighted tree T and two non-negative real numbers `d' and `D' such that each leaf `u' of T is a node of V and the edge `(u,v) belongs to E' iff `d <= d_T(u, v)…

Discrete Mathematics · Computer Science 2015-04-27 Tiziana Calamoneri , Blerina Sinaimeri , Mattia Gastaldello

A graph $G$ is called a pairwise compatibility graph (PCG) if there exists an edge weighted tree $T$ and two non-negative real numbers $d_{min}$ and $d_{max}$ such that each leaf $l_u$ of $T$ corresponds to a vertex $u \in V$ and there is…

Discrete Mathematics · Computer Science 2011-06-22 Tiziana Calamoneri , Rossella Petreschi , Blerina Sinaimeri

A graph $G=(V,E)$ with a vertex set $V$ and an edge set $E$ is called a pairwise compatibility graph (PCG, for short) if there are a tree $T$ whose leaf set is $V$, a non-negative edge weight $w$ in $T$, and two non-negative reals…

Data Structures and Algorithms · Computer Science 2020-07-23 Mingyu Xiao , Hiroshi Nagamochi

A graph $G$ is called a pairwise compatibility graph (PCG) if there exists an edge-weighted tree $T$ and two non-negative real numbers $d_{min}$ and $d_{max}$ such that each leaf $l_u$ of $T$ corresponds to a vertex $u \in V$ and there is…

Discrete Mathematics · Computer Science 2012-02-22 Tiziana Calamoneri , Dario Frascaria , Blerina Sinaimeri

A graph $G$ is a pairwise compatibility graph (PCG) if there exists an edge-weighted tree and an interval $I$, such that each leaf of the tree is a vertex of the graph, and there is an edge $\{ x, y \}$ in $G$ if and only if the weight of…

Combinatorics · Mathematics 2024-10-09 Tiziana Calamoneri , Manuel Lafond , Angelo Monti , Blerina Sinaimeri

Pairwise compatibility graphs (PCGs) with non-negative integer edge weights recently have been used to describe rare evolutionary events and scenarios with horizontal gene transfer. Here we consider the case that vertices are separated by…

Combinatorics · Mathematics 2020-05-26 Yangjing Long , Peter F. Stadler

A graph $G$ is called a pairwise compatibility graph (PCG, for short) if it admits a tuple $(T,w, d_{\min},d_{\max})$ of a tree $T$ whose leaf set is equal to the vertex set of $G$, a non-negative edge weight $w$, and two non-negative reals…

Data Structures and Algorithms · Computer Science 2020-07-23 Mingyu Xiao , Hiroshi Nagamochi

Pairwise Compatibility Graphs (PCGs) form a tree-metric graph class that originated in phylogeny and has since attracted sustained interest in graph theory. Several natural generalizations have been proposed in order to overcome the…

Combinatorics · Mathematics 2026-04-23 Sheikh Azizul Hakim , Md. Shamsuzzoha Bayzid

A graph G is a multi-interval PCG if there exist an edge weighted tree T with non-negative real values and disjoint intervals of the non-negative real half-line such that each node of G is uniquely associated to a leaf of T and there is an…

Discrete Mathematics · Computer Science 2026-04-08 Tiziana Calamoneri , Angelo Monti , Fabrizio Petroni

\noindent A paired coalition in a graph $G=(V,E)$ consists of two disjoint sets of vertices $V_1$ and $V_2$, neither of which is a paired dominating set but whose union $V_1 \cup V_2$ is a paired dominating set. A paired coalition partition…

Combinatorics · Mathematics 2024-08-15 Mohammad Reza Samadzadeh , Doost Ali Mojdeh , Reza Nadimi

Reconstruction of evolutionary relationships between species is an important topic in the field of computational biology. Pairwise compatibility graphs (PCGs) are used to model such relationships. A graph is a PCG if its edges can be…

Discrete Mathematics · Computer Science 2024-10-17 Seemab Hayat , Naveed Ahmed Azam

In this paper we consider Contact graphs of Paths on a Grid (CPG graphs), i.e. graphs for which there exists a family of interiorly disjoint paths on a grid in one-to-one correspondence with their vertex set such that two vertices are…

Computational Geometry · Computer Science 2018-09-07 Zakir Deniz , Esther Galby , Andrea Munaro , Bernard Ries

In this paper we continue the systematic study of Contact graphs of Paths on a Grid (CPG graphs) initiated in [Deniz et al., 2018]. A CPG graph is a graph for which there exists a collection of pairwise interiorly disjoint paths on a grid…

Computational Geometry · Computer Science 2020-01-28 Nicolas Champseix , Esther Galby , Andrea Munaro , Bernard Ries

Let $\mathcal{G}$ be the set of simple graphs (or multigraphs) $G$ such that for each $G \in \mathcal{G}$ there exists at least two non-empty disjoint proper subsets $V_{1},V_{2}\subseteq V(G)$ satisfying $V(G)\setminus(V_{1} \cup…

Combinatorics · Mathematics 2018-11-19 Cunxiang Duan , Ligong Wang , Xiangxiang Liu

A graph $G$ is a $B_0$-VPG graph if one can associate a path on a rectangular grid with each vertex such that two vertices are adjacent if and only if the corresponding paths intersect at at least one grid-point. A graph $G$ is a contact…

A graph $G$ is said to be the intersection of graphs $G_1,G_2,\ldots,G_k$ if $V(G)=V(G_1)=V(G_2)=\cdots=V(G_k)$ and $E(G)=E(G_1)\cap E(G_2)\cap\cdots\cap E(G_k)$. For a graph $G$, $\mathrm{dim}_{COG}(G)$ (resp. $\mathrm{dim}_{TH}(G)$)…

Discrete Mathematics · Computer Science 2020-01-06 Daphna Chacko , Mathew C. Francis

The families EPT (resp. EPG) Edge Intersection Graphs of Paths in a tree (resp. in a grid) are well studied graph classes. Recently we introduced the graph classes Edge-Intersecting and Non-Splitting Paths in a Tree ENPT, and in a Grid…

Discrete Mathematics · Computer Science 2023-06-22 Arman Boyacı , Tınaz Ekim , Mordechai Shalom , Shmuel Zaks

A walk $W$ in edge-colored graphs is called properly colored (PC) if every pair of consecutive edges in $W$ is of different color. We introduce and study five types of PC acyclicity in edge-colored graphs such that graphs of PC acyclicity…

Discrete Mathematics · Computer Science 2016-09-13 Gregory Gutin , Mark Jones , Bin Sheng , Magnus Wahlstrom , Anders Yeo

We introduce a new class of intersection graphs, the edge intersection graphs of paths on a triangular grid, called EPGt graphs. We show similarities and differences from this new class to the well-known class of EPG graphs. A turn of a…

Discrete Mathematics · Computer Science 2022-03-09 Vitor T. F. de Luca , María Pía Mazzoleni , Fabiano S. Oliveira , Tanilson D. Santos , Jayme L. Szwarcfiter
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