  Let k be a perfect field and A a finite dimensional k-algebra of finite
global dimension (e.g. the path algebra of a finite quiver without oriented
cycles). Making use of the recent theory of noncommutative motives, we prove
that the value of every additive invariant at A only depends on the number of
simple modules. Examples of additive invariants include algebraic K-theory,
cyclic homology (and all its variants), topological Hochschild homology, etc.
Along the way we establish two results of general interest. The first one
concerns the compatibility between bilinear pairings and Galois actions on the
Grothendieck group of every proper dg category. The second one is a transfer
result in the setting of noncommutative motives.
