3 papers
math.AG2026
Computing Cox rings via the cone conjecture
Tomoki Oda, José Ignacio Yáñez, Juan Pablo Zúñiga
We initiate a program to study the Cox ring of Calabi-Yau varieties, employing the notion of Morrison-Kawamata dream spaces. In this setting, we establish an analogue of the Hu-Kee…
math.AG2026
Bianchi groups and automorphisms of rank-four surfaces
Kenji Hashimoto, Tomoki Oda
We relate the arithmetic of Bianchi groups to automorphism groups of Picard-rank-four surfaces. Let be an imaginary quadratic field with ring of integers , a…
math.AG2025
Geometry of tropical mutation surfaces with a single mutation
Tomoki Oda
Escobar, Harada, and Manon introduced polyptych lattices as a piecewise-linear extension of the lattice-polytope formalism of toric geometry. In this paper we study the first genui…