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1 vote
0 answers
18 views

How sensitive are maximum-size matchings to edge deletion in random graphs?

My question concerns the sensitivity of maximum-size matchings (and more generally maximum-size $k$-cycle collections) to deletion of an edge in the graph. Given a graph $G$, let a $k$-cycle be a ...
user1326274's user avatar
1 vote
0 answers
58 views

Distribution of $k$-matchings in a random graph

Take the Erdos-Renyi random graph $G(n,p)$, i.e. the random graph with $n$ vertices and where each possible edge has an independent probability of $p$ of being present. Recall that a $k$-matching is a ...
Harry Vinall-Smeeth's user avatar
4 votes
1 answer
225 views

How many connected components in this random graph?

I was reading this blog post about minimum-weight matchings on two-color point sets in the unit square and it got me thinking. Suppose you have 3 colors (Red, Blue, Green), and randomly drop $N$ ...
Craig's user avatar
  • 3,536
2 votes
1 answer
249 views

Threshold function for the existence of a perfect matching in $G(n,p)$ (from the book of Frieze and Karonski)

I'm reading Introduction to Random Graphs by Frieze and Karonski. Theorem 6.2 determines the threshold for the appearance of a perfect matching in $\mathbf{G}_{n,p}$: Let $\omega=\omega(n)$, $c>0$...
35T41's user avatar
  • 3,407
0 votes
1 answer
71 views

Vertex expander bounded away from zero

Show that for a family of ε-vertex expanders the expansion parameter $h(G_j )$ stays bounded away from 0. Conversely, let $G_1$, $G_2$, . . . be a sequence of k-regular graphs whose number of vertices ...
james black's user avatar
  • 1,913
0 votes
1 answer
67 views

Vertex expander bounded

Let $G_1$, $G_2$, . . . be a family of ε-vertex expanders on $n_1$, $n_2$, . . . vertices. Show that there is a constant c such that eventually the diameter of $G_j$ is bounded from above by c · log($...
james black's user avatar
  • 1,913
2 votes
1 answer
524 views

Perfect matching in a random bipartite graph with edge probability 1/2

I am trying to prove that, when given a bipartite graph $G=(X \cup Y, E)$ with $|X|=|Y|=n$ and edge probability $\frac{1}{2}$, as $n\rightarrow \infty$ the probability of the graph having a perfect ...
user avatar
2 votes
1 answer
356 views

Perfect matching in random bipartite graph - with fixed probability

as a follow up from this question : Suppose that we have a simpler problem, where the probability $p$ is fixed. Of course we could use the above result to proove that almost every graph in the model ...
Thomas Lesgourgues's user avatar