학술논문

A module-theoretic approach to matroids
Document Type
Working Paper
Source
Journal of Pure and Applied Algebra 224.2 (2020) 894-916
Subject
Mathematics - Algebraic Geometry
Mathematics - Combinatorics
05B35, 14T05, 12K10
Language
Abstract
Speyer recognized that matroids encode the same data as a special class of tropical linear spaces and Shaw interpreted tropically certain basic matroid constructions; additionally, Frenk developed the perspective of tropical linear spaces as modules over an idempotent semifield. All together, this provides bridges between the combinatorics of matroids, the algebra of idempotent modules, and the geometry of tropical linear spaces. The goal of this paper is to strengthen and expand these bridges by systematically developing the idempotent module theory of matroids. Applications include a geometric interpretation of strong matroid maps and the factorization theorem; a generalized notion of strong matroid maps, via an embedding of the category of matroids into a category of module homomorphisms; a monotonicity property for the stable sum and stable intersection of tropical linear spaces; a novel perspective of fundamental transversal matroids; and a tropical analogue of reduced row echelon form.
Comment: 22 pages; v3 minor corrections/clarifications; to appear in JPAA