Tsukasa Ishibashi

activity

20242026

collaborators

6 papers

math.GT2026

Adjoint Reidemeister torsion of 3-manifolds with torus boundary for semisimple algebraic groups

Tsukasa Ishibashi, Yuma Mizuno

Let $M$ be a compact oriented $3$ -manifold with boundary consisting of tori, and let $G$ be a semisimple algebraic group. We define the adjoint torsion function on the moduli stack…

math.GT2026

Fixed point theorem for cluster modular groups

Tsukasa Ishibashi

We prove that any finite subgroup $G \subset I^_{s}$ of the cluster modular group has fixed points in the cluster manifolds $\mathcal{A}_{\boldsymbol{s}}(\mathbb{R}_{>…

math.AG2025

Bounded $sp_{4}$ -laminations and their intersection coordinates

Tsukasa Ishibashi, Zhe Sun, Wataru Yuasa

We introduce rational bounded $sp_{4}$ -laminations on a marked surface $I^£$ as a proposed topological model for the rational tropical points $\mathcal{A}_{Sp_4,…

math.GT2025

Quantum duality maps, skein algebras and their ensemble compatibility

Tsukasa Ishibashi, Hiroaki Karuo

We generalize the quantum duality map $I_{A}$ of Allegretti--Kim [AK17] for punctured closed surfaces to general marked surfaces. When the marked surface has no…

math.GT2024

A characterization of pseudo-Anosov mapping classes via tropical cluster transformations

Tsukasa Ishibashi, Shunsuke Kano

We give a characterization of generic pseudo-Anosov mapping classes purely in terms of their expressions in the shear coordinates, thus giving an answer to a problem raised by Papa…

math.GT2024

Earthquake theorem for cluster algebras of finite type

Takeru Asaka, Tsukasa Ishibashi, Shunsuke Kano

We introduce a cluster algebraic generalization of Thurston's earthquake map for the cluster algebras of finite type, which we call the \emph{cluster earthquake map}. It is defined…