Skip to main content

All Questions

1 vote
0 answers
65 views

Why is the formula of edges$=$nodes$-$1 for modeling radiality very slow?

Suppose $G$ is a graph. $E(G)$ and $V(G)$ denote the sets of the edges and nodes (vertices) of $G$, respectively. I need a spanning subgraph of $G$ (let’s call the subgraph $g$). The subgraph must be ...
Mahdi Rouholamini's user avatar
2 votes
1 answer
121 views

Vertex minors of paths

(Vertex Minor) A graph H is a vertex minor of G if H can be obtained from G by a sequence of vertex deletions and local complementation (Local complementation) A local complementation $\tau_v$ is a ...
Dotman's user avatar
  • 326
0 votes
0 answers
44 views

Comparing networks using graph theory

I'm new to graph theory so forgive if I use unconventional terminology. Please ask if there's any confusion regarding the statements I make. I have a bunch of undirected, unweighted, simple graphs ...
Dotman's user avatar
  • 326
1 vote
0 answers
34 views

Expand acyclic graphs to acyclic graphs

I am learning about Kruskal Algorithm to find minimal spanning trees. To show that the spanning tree which is constructed with that Algorithm is minimal, I need to prove this statement: Let $G=(V,E)$ ...
Lord Vader's user avatar
3 votes
1 answer
333 views

Requirements for embedding a graph in n-dimensional euclidean space

Given a graph $G = (V, E)$, I want to embed it into a $n$-dimensional space $\mathbb{R}^n$, while respecting the following conditions: Let $x_i$ be the $n$-dimensional embedding of vertex $v_i$. If $...
Federico Taschin's user avatar
3 votes
1 answer
270 views

Graphs on Cylinders

I know that nonplanar graphs can be embedded without self-intersection into a $g$-holed torus, for sufficiently large $g$. In particular, I know that $K_5$ and $K_{3,3}$ can be embedded into the torus....
perpetuallyconfused's user avatar
0 votes
1 answer
65 views

Generalization of complete bipartite graphs [closed]

The concept of complete bipartite graphs can be generalized to define the complete multipartite graph $K_{r_1, r_2, ..., r_k}$. This graph consists of $k$ sets of vertices $A_1, A_2, ..., A_k$, with $...
Alvaro's user avatar
  • 3
1 vote
1 answer
269 views

number of closed-loop graphs in square lattice

Suppose I have a $N\times N$ square lattice. I want to know how many different closed-loop diagrams are there. The closed-loop diagrams can have no loop, one loop, two loops, etc. If two loops share ...
lol's user avatar
  • 185
1 vote
0 answers
70 views

Materials to read for Graph Theory.

I am interested in graph theory and currently finished learning the basic knowledge in graph theory. Before I continue on to study the following three branch of graph theory, namely Topological Graph ...
Nothing's user avatar
  • 1,718
7 votes
2 answers
261 views

Going with/against the orientation alternates along the Hamilton cycle?

Below you see an example of a bicubic graph consisting of faces with degree $4$ and $6$, which makes up the set of graphs of my interest and is a subset of the so called Barnette graphs. $\hskip1....
draks ...'s user avatar
  • 18.6k
1 vote
1 answer
101 views

Surjective homomorphism preserves planarity?

I was just wondering if for surjective homomorphism of G to H, where G is planar hold that H is planar as well. This is clearly false for non-surjective ones, but for surjective? How it is with ...
user avatar
1 vote
1 answer
6k views

what is the maximum number of faces with n vertex in planar graphs?

what is the maximum number of faces with n vertex in planar graphs? v=number of vertices f= number of faces for example if v=3 -> max(f)=2 v=4 -> max(f)=4 (a triangle with a point in inner face of ...
abdolah's user avatar
  • 137