resilience of graphs question

157 Views Asked by At

The following is a definition of the resilience of a graph w.r.t to a property $\mathcal{P}$

(Local resilience) A property $\mathcal{P}$ is said to be monotone if the property is preserved under edge addition. Given a monotone increasing property $\mathcal{P}$. The local resilience of a graph $G$ with respect to $\mathcal{P}$ is the minimum number $r$ such that by deleting at each vertex of $G$ at most $r$ edges one can obtain a graph not having $\mathcal{P}$.

In a paper i'm reading they say the following two statements 1. and 2. are equal in regards to resilience.

  1. What is the local resilience of the hypercube with respect to containing a perfect matching?
  2. In other words, what is the minimum degree of a subgraph of the hypercube containing an edge from every perfect matching?

My question is why? Surely you need the smallest maximum degree of a subgraph of the hypercube containing an edge from every perfect matching? As you will need to delete at most this many edges from each vertex to remove any perfect matching?