Bipartite graphs and isolated vertices

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In summary, the speaker is looking for the threshold function p=p(n) for a random bipartite graph with 2n vertices, such that for p>p(n) there are no isolated vertices and for p<p(n) there is at least one isolated vertex. They mention that for normal non-bipartite graphs with n vertices, the probability is p(n)=log(n)/n, and they suspect that in this case the function is klog(n)/n. They are requesting help and asking for any thoughts on the matter.
  • #1
simba31415
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Homework Statement


Hello everyone,

I am trying to determine the the threshold function p=p(n) for a random bipartite graph (see http://en.wikipedia.org/wiki/Erdős–Rényi_model for a 'random graph': I am interested in the same idea, but for random bipartite graphs), such that for a random bipartite graph with 2n vertices (n in each vertex set), with edge probability p>p(n) we almost surely have no isolated vertex as [itex]n \to \infty[/itex] and with p<p(n) we almost surely have an isolated vertex.

I am aware that for normal non-bipartite graphs with n vertices, the probability is p(n)=log(n)/n: I suspect in this case the function is something like klog(n)/n: could anyone help me, please? Thankyou ever so much :)
 
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  • #2
Just thought i'd check again, nobody has any thoughts on this perhaps? :)
 
  • #3
Aaanyone? If not, I guess the mods should feel free to close this thread!
 

1. What is a bipartite graph?

A bipartite graph is a type of graph where the vertices can be divided into two disjoint sets such that no two vertices within the same set are connected by an edge. This means that all edges in a bipartite graph connect a vertex from one set to a vertex from the other set.

2. How do you identify isolated vertices in a bipartite graph?

An isolated vertex in a bipartite graph is a vertex that is not connected to any other vertices. It can be identified by checking if the degree of that vertex is 0, meaning it has no edges connected to it.

3. Can a bipartite graph have an odd cycle?

No, a bipartite graph cannot have an odd cycle. This is because in a bipartite graph, all edges connect vertices from different sets, so it is impossible to form a cycle with an odd number of vertices.

4. How many edges can a bipartite graph have?

The maximum number of edges in a bipartite graph with n vertices is n^2/4. This occurs when the two sets have an equal number of vertices.

5. What are some real-world applications of bipartite graphs?

Bipartite graphs can be used to model relationships between two different types of entities, such as actors and movies in a movie database, or users and products in an e-commerce website. They can also be used in matchmaking algorithms, where the goal is to match two sets of people based on their preferences or compatibility.

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