Random walks on G

Markov process with state graph G

Take a Markov chain with probability matrix Pu,v=1deg(u). πv=d(v)2|E|. \chk

Hitting and cover times

Hitting time hu,v: expected time to get to v from u. Commute time: Cu,v=hu,v+hv,u. hu,v<2|E| \why.

Cover time C(G) = maxv E[time to hit all nodes starting from v]. C(G)<4|V||E| \why.

Connection with resistive electric networks

Let every eE have resistance 1, thence get n/w N(G). Ru,v: effective resistance between u, v. Cu,v=2mRu,v \why.