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Related papers: The tropical galaxy of a Laman graph

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We prove that the proper amalgam of matroids $M_1$ and $M_2$ along their common restriction $N$ exists if and only if the tropical fibre product of Bergman fans ${B(M_1) \times_{B(N)} B(M_2)}$ is positive. We introduce tropical…

Algebraic Geometry · Mathematics 2024-04-30 Dmitry Mineev

In 2015, Cartwright et al. showed that any $3$-regular metric graph arises as the skeleton of a tropical plane curve with nodes allowed. They introduced the tropical crossing number of a metric graph as the minimum number of nodes required…

Combinatorics · Mathematics 2025-08-21 Noah Cape , Ralph Morrison

Let $G$ be a graph and $\gamma (G)$ denote the domination number of $G$, i.e. the cardinality of a smallest set of vertices $S$ such that every vertex of $G$ is either in $S$ or adjacent to a vertex in $S$. Matheson and Tarjan conjectured…

Combinatorics · Mathematics 2019-03-07 Michael D. Plummer , Dong Ye , Xiaoya Zha

We study the locus of tropical hyperelliptic curves inside the moduli space of tropical curves of genus g. We define a harmonic morphism of metric graphs and prove that a metric graph is hyperelliptic if and only if it admits a harmonic…

Combinatorics · Mathematics 2011-10-04 Melody Chan

We study whether a given tropical curve $\Gamma$ in $\mathbb{R}^n$ can be realized as the tropicalization of an algebraic curve whose non-archimedean skeleton is faithfully represented by $\Gamma$. We give an affirmative answer to this…

Algebraic Geometry · Mathematics 2017-02-17 Man-Wai Cheung , Lorenzo Fantini , Jennifer Park , Martin Ulirsch

Given a tropical linear space $L \subseteq \mathbb{T}^n$ and a matrix $A \in \mathbb{T}^{m \times n}$, the image $AL$ of $L$ under $A$ is typically not a tropical linear space. We introduce a tropical linear space $\mathrm{tropim}_A(L)$,…

Algebraic Geometry · Mathematics 2018-08-08 Joshua Mundinger

We study a notion of tropical linear series on metric graphs that combines two essential properties of tropicalizations of linear series on algebraic curves: the Baker-Norine rank and the independence rank. Our main results relate the local…

Algebraic Geometry · Mathematics 2025-09-05 Chih-Wei Chang , Matthew Dupraz , Hernan Iriarte , David Jensen , Dagan Karp , Sam Payne , Jidong Wang

We determine the maximum number of edges of an $n$-vertex graph $G$ with the property that none of its $r$-cliques intersects a fixed set $M\subset V(G)$. For $(r-1)|M|\ge n$, the $(r-1)$-partite Turan graph turns out to be the unique…

Combinatorics · Mathematics 2017-07-31 Peter Allen , Julia Böttcher , Jan Hladký , Diana Piguet

A set of vertices $S$ resolves a graph $G$ if every vertex is uniquely determined by its vector of distances to the vertices in $S$. The metric dimension of $G$ is the minimum cardinality of a resolving set of $G$. Let $\{G_1, G_2, \ldots,…

Combinatorics · Mathematics 2015-12-24 Rinovia Simanjuntak , Saladin Uttunggadewa , Suhadi Wido Saputro

The linear arboricity of a graph $G$, denoted by $\text{la}(G)$, is the minimum number of edge-disjoint linear forests (i.e. forests in which every connected component is a path) in $G$ whose union covers all the edges of $G$. A famous…

Combinatorics · Mathematics 2018-09-14 Asaf Ferber , Jacob Fox , Vishesh Jain

We study tropically planar graphs, which are the graphs that appear in smooth tropical plane curves. We develop necessary conditions for graphs to be tropically planar, and compute the number of tropically planar graphs up to genus $7$. We…

Algebraic Geometry · Mathematics 2020-02-06 Desmond Coles , Neelav Dutta , Sifan Jiang , Ralph Morrison , Andrew Scharf

The edge domination number $\gamma_e(G)$ of a graph $G$ is the minimum size of a maximal matching in $G$. It is well known that this parameter is computationally very hard, and several approximation algorithms and heuristics have been…

Combinatorics · Mathematics 2019-05-30 Julien Baste , Maximilian Fürst , Michael A. Henning , Elena Mohr , Dieter Rautenbach

A tropical curve \Gamma is a metric graph with possibly unbounded edges, and tropical rational functions are continuous piecewise linear functions with integer slopes. We define the complete linear system |D| of a divisor D on a tropical…

Algebraic Geometry · Mathematics 2016-08-22 Christian Haase , Gregg Musiker , Josephine Yu

For a graph $G$, a subset $S$ of $V(G)$ is a {\it hop dominating set} of $G$ if every vertex not in $S$ has a $2$-step neighbor in $S$. The {\it hop domination number}, $\gamma_h(G)$, of $G$ is the minimum cardinality of a hop dominating…

Combinatorics · Mathematics 2025-03-07 Shinya Fujita , Boram Park

We study the tropicalization of intersections of plane curves, under the assumption that they have the same tropicalization. We show that the set of tropical divisors that arise in this manner is a pure dimensional balanced polyhedral…

Algebraic Geometry · Mathematics 2019-05-02 Yoav Len , Matthew Satriano

This thesis delves into the geometry of abstract tropical curves, exploring their complete linear system and associated tropical submodules. We establish a lower bound on the dimension of tropical submodules in terms of the Baker-Norine…

Algebraic Geometry · Mathematics 2025-06-27 Matthew Dupraz

We revisit the concept of minimal rigidity as applied to soft repulsive, frictionless sphere packings in two-dimensions with the introduction of the jamming graph. Minimal rigidity is a purely combinatorial property encoded via Laman's…

Soft Condensed Matter · Physics 2015-06-16 Jorge H. Lopez , L. Cao , J. M. Schwarz

We undertake a combinatorial study of the piecewise linear map g : R^{2m+2n} --> R^{mn} which assigns to the four vectors a, A in R^m and b, B in R^n the m by n matrix given by g_{ij} = min (a_i + b_j, A_i+B_j). This map arises naturally in…

Combinatorics · Mathematics 2007-05-23 Federico Ardila

For a connected smooth projective curve $X$ of genus $g$, global sections of any line bundle $L$ with $\deg(L) \geq 2g+ 1$ give an embedding of the curve into projective space. We consider an analogous statement for a Berkovich skeleton in…

Algebraic Geometry · Mathematics 2017-04-07 Shu Kawaguchi , Kazuhiko Yamaki

Let $G$ be a finite group and let $N$ be a normal subgroup of $G$. We attach to $N$ two graphs ${\Gamma}_G(N)$ and ${\Gamma}^{\ast}_G(N)$ related to the conjugacy classes of $G$ contained in $N$ and to the set of primes dividing the sizes…

Group Theory · Mathematics 2024-02-12 Antonio Beltrán , María José Felipe , Carmen Melchor