Chromatic number of a graph embedded on torus

In summary, the chromatic number of a graph embedded on a torus is the minimum number of colors needed to color all of the vertices of the graph without any adjacent vertices having the same color. This number can be calculated using various algorithms that take into account the topology and connectivity of the torus. The chromatic number can change depending on the specific graph and its embedding, providing insights into its complexity and structure. It can also have practical applications in problem-solving. However, the maximum chromatic number on a torus cannot exceed the number of vertices in the graph.
  • #1
abdolah
2
0
if the graph G can be embedded on a torus can we say:

if

χ(G)≥r⇒Kr≺G.

Kr is a minor of G?(Kr is the complete graph with r vertices).
 
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  • #2
No, this is not necessarily true. A graph can be embedded on a torus and still not contain a minor of the complete graph with r vertices.
 

FAQ: Chromatic number of a graph embedded on torus

What is the chromatic number of a graph embedded on a torus?

The chromatic number of a graph embedded on a torus is the minimum number of colors needed to color all of the vertices of the graph in such a way that no two adjacent vertices have the same color.

How is the chromatic number of a graph embedded on a torus calculated?

The chromatic number of a graph embedded on a torus can be calculated using various algorithms, such as the Four Color Theorem or the Heawood Conjecture. These algorithms take into account the topology and connectivity of the torus to determine the minimum number of colors needed.

Can the chromatic number of a graph embedded on a torus change?

Yes, the chromatic number of a graph embedded on a torus can change depending on the specific graph and its embedding. For example, a graph with a higher degree of connectivity or more complex topology may require more colors than a simpler graph on the same torus.

What is the significance of the chromatic number of a graph embedded on a torus?

The chromatic number of a graph embedded on a torus can provide insights into the complexity and structure of the graph. It can also have practical applications, such as in scheduling and resource allocation problems.

Can the chromatic number of a graph embedded on a torus be greater than the number of vertices in the graph?

No, the chromatic number of a graph embedded on a torus cannot be greater than the number of vertices in the graph. This is because at least one color will always be used for each vertex, and the remaining colors will be used for adjacent vertices. Therefore, the maximum chromatic number on a torus is equal to the number of vertices in the graph.

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