Relating Different Definitions of Linear Series on Tropical Curves
Eric Burkholder
TL;DR
This work unifies two tropical theories of linear series by proving that strongly recursive tropical linear series of rank $r$ always yield combinatorial limit linear series of rank $r$, while providing counterexamples to the converse for $r\ge 3$. It develops a robust local-array framework that links global submodule structure to local permutation-arrays, employs slope-structure notions, and analyzes Baker–Norine rank properties via slope limits. Extensions include relaxing locality conditions, establishing structured TLS equivalence with CLLS, and exploring realizability of permutation arrays as local arrays under both frameworks. The results illuminate when tropical linear series can be realized combinatorially and offer a fertile ground for further questions on higher-rank realizability and the full TLS vs. CLLS equivalence spectrum.
Abstract
We compare strongly recursive tropical linear series as defined by Farkas, Jensen, and Payne with combinatorial limit linear series as defined by Amini and Gierczak. We show that strongly recursive tropical linear series of rank $r$ are combinatorial limit linear series of rank $r$ and construct a counterexample to the converse. We also present several extensions of our main result, including a simplification of the definition of combinatorial limit linear series and an investigation of their relationship with tropical linear series in the sense of Chang et al. Finally, we address the realizability of permutation arrays as local arrays of linear series on tropical curves. Finally, discuss the realizability of permutation arrays as local arrays of linear series on tropical curves.
