collaborators

7 papers

math.CO2026

Geometric structures of -fans associated with rank cluster-cyclic exchange matrices

Ryota Akagi, Zhichao Chen

In this paper, we investigate the geometric structures of -fans associated with rank real cluster-cyclic exchange matrices. In this class, a simple recursion for tropical si…

math.RT2026

Real -, -structures and sign-coherence of cluster algebras

Ryota Akagi, Zhichao Chen

We generalize the theory of integer -, -matrices in cluster algebras to the real case. By a skew-symmetrizing method, we can reduce the problem of skew-symmetrizable patterns…

math.RT2026

Fractal phenomenon in - and -vectors of the Markov quiver

Ryota Akagi, Zhichao Chen

We study the - and -patterns associated with rank skew-symmetrizable matrices of -invariant type, including the Markov quiver. Motivated by the self-contained simple m…

math.RT2026

Relation between generalized and ordinary cluster algebras

Ryota Akagi, Tomoki Nakanishi

Recently, Ramos and Whiting showed that any generalized cluster algebra of geometric type is isomorphic to a quotient of a subalgebra of a certain cluster algebra. Based on their i…

math.CO2025

Some coefficients of rank 2 cluster scattering diagrams

Ryota Akagi

The purpose of this paper is to translate the expression of rank 2 cluster scattering diagrams via dilogarithm elements into via formal power series. As a corollary, we prove some…

math.CO2025

Sign-coherence and tropical sign pattern for rank real cluster-cyclic exchange matrices

Ryota Akagi, Zhichao Chen

The sign-coherence about -vectors was conjectured by Fomin-Zelevinsky and solved completely by Gross-Hacking-Keel-Kontsevich for integer skew-symmetrizable case. We prove this c…