29 Sep
2006
29 Sep
'06
3:50 p.m.
I also posted my question to the domino forum (see jamespropp.org/about-domino) and got (1) a solution by Hugh Thomas and (2) a reference to the literature: H. Wielandt: Unzerlegbare, nicht negative Matrizen, (Engl.: Irreducible non-negative matrices) Math. Z. 52 (1950) 642-648. The optimal (or pessimal, depending on your point of view) matrices look like [0 + 0 0] [0 0 + 0] [0 0 0 +] [+ + 0 0] (as Dan Asimov observed). Thanks to all who responded (on- or off-line)! Jim Propp