The number of arrows in the quiver of tilting modules over a path algebra of Dynkin type. (Q357451)

Let \(Q\) be a Dynkin quiver and let \(kQ\) be the path algebra of \(Q\), where \(k\) is an algebraically closed field. Happel and Unger defined a partial order on the set of basic tilting modules. The tilting quiver \(\overrightarrow{\mathcal K}(kQ)\) is the Hasse diagram of this partial order. The author gives formulas for the number of arrows in \(\overrightarrow{\mathcal K}(kQ)\) for any Dynkin quiver \(Q\).