Week 1 - lecture 2


Date: 01/09/22

1.6. Reversibility and Time Reversals
1.7. Eulerian graphs
1.8. Harmonic functions
1.9. Gambler's Ruin

LECTURE presentation

Video lecture


1.  A  connected graph is a tree if it contains no cycles. Show that every finite tree with at least two vertices must have at least two leaves. (a leaf is a vertex of degree 1).
2.  A vertex coloring of a graph is called proper if every pair of  adjacent vertices are assigned different colors. Consider the following Markov chain on the set of proper 3 colorings of a finite tree T: At each step, a vertex w of T is selected uniformly at random, and is assigned randomly, uniformly  one of the colors that does not appear among the neighbors of w . Show that this chain is irreducible.
3.  Let P be a transition matrix on a finite set V. Suppose that \pi is a stationary distribution for P and \pi(z)>0. Show  that E_z(\tau^+_z )<\infty.




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