Intersection vectors over tilings with applications to gentle algebras and cluster algebras

Abstract

It is proved that a multiset of permissible arcs over a tiling is uniquely determined by its intersection vector under a mild condition. This generalizes a classical result over marked surfaces with triangulations. We apply this result to study $\tau$-tilting theory of gentle algebras and denominator conjecture in cluster algebras. In the case of gentle algebras, it is proved that different $\tau$-rigid $A$-modules over a gentle algebra $A$ have different dimension vectors if and only if $A$ has no even oriented cycle with full relations. For cluster algebras, the denominator conjecture has been established for cluster algebras of type $\mathbb{ABC}$.

The proof of Lemma 2.8 (Lemma 2.3 in v1) is improved. Any comments are welcome!