Work

Congruence spectra and geometric reconstruction of $\boldsymbol{T}$-algebras

Year: 2026
Type: preprint
Abstract: We develop a geometric theory of congruence spectra for semirings. We define the congruence spectrum for a semiring as the set of prime congruences on it, equip it with the Zariski topology, and construct a structure sheaf. For a class of semirings including $\boldsymbol{B}$-algebras, we establish quasi-compactness of their congruence spectra. We then prove reconstruction results for congruence spectra of quotients $K/\boldsymbol{E}(V)$, where $V$ is a subset of Euclidean space, $K$ is a tropical Laurent polynomial semiring, a tropical Laurent polynomial function semiring, or a tropical rational function semifield, and $\boldsymbol{E}(V)$ is the congruence of pairs of elements of $K$ that agree on $V$. The global sections of the structure sheaf recover $K/\boldsymbol{E}(V)$, and the corresponding algebraic and geometric categories are contravariantly equivalent. For finite unions of $\boldsymbol{R}$-rational polyhedral sets $V$, we completely classify the prime congruences on $K / \boldsymbol{E}(V)$. As an application, we study rational function semifields of tropical curves with parallel rays. We show that their congruence spectra recover the underlying curves together with the parallelism of rays and their intrinsic metrics.
Author: Song, JuAe
Language: English
Open Access status: green
OpenAlex ID: W7214301649
Cites: 4
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Related to: 10