Newton polytopes in cluster algebras and $τ$-tilting theory
Peigen Cao
TL;DR
The paper addresses whether Newton polytopes of $F$-polynomials determine key objects in cluster algebras and $\tau$-tilting theory. It develops the $F$-invariant and its module-analogue to connect polytope geometry with algebraic structure, using left Bongartz completion and reduction arguments. The main results show that cluster monomials in non-initial variables are uniquely determined by $P(F_u^{t_0})$ and that indecomposable $\tau$-rigid modules and left finite multi-semibricks are likewise determined by the Newton polytopes of their $F$-polynomials, i.e., by $P(F_M)$ or $\mathsf P(M)$. These findings link cluster algebras and $\tau$-tilting theory through Newton polytopes, offering a polyhedral lens on classification and mutation phenomena with potential implications for parametrization by polytopes in representation theory and categorification.
Abstract
We prove that the cluster monomials in non-initial cluster variables are uniquely determined by the Newton polytopes of their $F$-polynomials for skew-symmetrizable cluster algebras. Accordingly, we prove that the $τ$-rigid modules and the left finite multi-simibricks in $τ$-tilting theory are uniquely determined by their Newton polytopes of these modules.
