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Related papers: Torelli theorem for graphs and tropical curves

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We give a necessary and sufficient graph-theoretic characterization of toric ideals of graphs that are unimodular. As a direct consequence, we provide the structure of unimodular graphs by proving that the incidence matrix of a graph $G$ is…

Commutative Algebra · Mathematics 2025-10-15 Christos Tatakis

This work re-examines a classical construction of a 2-connected (simple) graph where every intermediate graph is 2-connected before detailing an analogous construction for 3-connected graphs which requires a graph equivalence relation…

Combinatorics · Mathematics 2015-12-01 Jonathan McLaughlin

We give a sufficient condition on totally disconnected topological graphs such that their associated topological graph algebras are purely infinite.

Operator Algebras · Mathematics 2017-03-31 Hui Li

We show that the Fourier transform on the Jacobian of a curve interchanges "$\delta$ functions" at the curve and the theta divisor. The Torelli theorem is an immediate consequence.

Algebraic Geometry · Mathematics 2007-05-23 Alexander Beilinson , Alexander Polishchuk

The deck of a graph $X$, $D(X)$, is defined as the multiset of all vertex-deleted subgraphs of $X$. Two graphs are said to be hypomorphic, if they have the same deck. Kelly-Ulam conjecture states that any two hypomorphic graphs on at least…

General Mathematics · Mathematics 2018-01-01 Adel Tadayyonfar , Ali Reza Ashrafi

We show that two smooth projective curves C_1 and C_2 of genus g which have isomorphic symmetric products are isomorphic unless g=2. This extends a theorem of Martens.

Algebraic Geometry · Mathematics 2021-09-28 Najmuddin Fakhruddin

A framework to handle tree decompositions of the components of a Borel graph in a Borel fashion is introduced, along the lines of Tserunyan's Stallings Theorem for equivalence relations arXiv:1805.09506. This setting leads to a notion of…

Logic · Mathematics 2023-08-28 Héctor Jardón-Sánchez

If a graph can be drawn on the torus so that every two independent edges cross an even number of times, then the graph can be embedded on the torus.

Discrete Mathematics · Computer Science 2021-04-14 Radoslav Fulek , Michael J. Pelsmajer , Marcus Schaefer

We give a short proof that every finite graph (or matroid) has a tree-decomposition that displays all maximal tangles. This theorem for graphs is a central result of the graph minors project of Robertson and Seymour and the extension to…

Combinatorics · Mathematics 2016-06-01 Johannes Carmesin

We consider three classes of geodesic embeddings of graphs on Euclidean flat tori: (1) A toroidal graph embedding $\Gamma$ is positive equilibrium if it is possible to place positive weights on the edges, such that the weighted edge vectors…

Metric Geometry · Mathematics 2022-02-08 Jeff Erickson , Patrick Lin

Perfect graphs form one of the distinguished classes of finite simple graphs. In 2006, Chudnovsky, Robertson, Seymour and Thomas proved that a graph is perfect if and only if it has no odd holes and no odd antiholes as induced subgraphs,…

Commutative Algebra · Mathematics 2023-07-14 Hidefumi Ohsugi , Kazuki Shibata , Akiyoshi Tsuchiya

We present a canonical way to decompose finite graphs into highly connected local parts. The decomposition depends only on an integer parameter whose choice sets the intended degree of locality. The global structure of the graph, as…

Combinatorics · Mathematics 2025-07-01 Reinhard Diestel , Raphael W. Jacobs , Paul Knappe , Jan Kurkofka

Torelli's theorem is proven by the study of the convolution product of the intersection cohomology sheaf of the thetadivisor.

Algebraic Geometry · Mathematics 2007-05-23 Rainer Weissauer

We define pure graphs, invertible graphs, and the notion of complementation of bicoloured graphs. The study of pure graphs is motivated by two conjectures about the transition systems of eulerian graphs and by the Cycle Double Cover…

Combinatorics · Mathematics 2007-05-23 François Genest

We generalise structure tree theory, which is based on removing finitely many edges, to removing finitely many vertices. This gives a significant generalization of Tutte's tree decomposition of 2-connected graphs into 3-connected blocks.…

Group Theory · Mathematics 2015-01-05 M. J. Dunwoody , B. Krön

Robertson and Seymour proved two fundamental theorems about tangles in graphs: the tree-of-tangles theorem, which says that every graph has a tree-decomposition such that distinguishable tangles live in different nodes of the tree, and the…

Combinatorics · Mathematics 2025-01-08 Sandra Albrechtsen

We compute the automorphism groups of the Torelli complex and the complex of separating curves for all but finitely many compact orientable surfaces. As an application, we show that the abstract commensurators of the Torelli group and the…

Group Theory · Mathematics 2015-02-02 Yoshikata Kida

We prove an analogue of Clifford's inequality for tropical curves. Next we focus on the hyperelliptic case and we characterize divisors attaining equality. Finally we speculate whether inequality in tropical Clifford's Theorem does imply…

Algebraic Geometry · Mathematics 2010-02-23 Laura Facchini

Duality of curves is one of the important aspects of the ``classical'' algebraic geometry. In this paper, using this foundation, the duality of tropical polynomials is constructed to introduce the duality of Non-Archimedean curves. Using…

Algebraic Geometry · Mathematics 2007-05-23 Zur Izhakian

Tropicalization is a procedure for associating a polyhedral complex in Euclidean space to a subvariety of an algebraic torus. We study the question of which graphs arise from tropicalizing algebraic curves. By using Baker's specialization…

Algebraic Geometry · Mathematics 2011-08-23 Eric Katz