Tilting Quivers for Hereditary Algebras

Let A be a finite dimensional hereditary algebra over an algebraically closed field k. In this paper, we study the tilting quiver of A from the viewpoint of tau-tilting theory. First, we prove that there exists an isomorphism between the support tau-tilting quiver Q(s tau-tilt of A and the tilting quiver Q(tilt A over bar ) of the duplicated algebra A over bar . Then, we give a new method to calculate the number of arrows in the tilting quiver Q(tilt A) when A is representation-finite. Finally, we study the conjecture given by Happel and Unger, which claims that each connected component of Q(tilt A) contains only finitely many non-saturated vertices. We provide an example to show that this conjecture does not hold for some algebras whose quivers are wild with at least four vertices.