English
Related papers

Related papers: Torelli theorem for graphs and tropical curves

200 papers

The Ramsey's theorem says that a graph with sufficiently many vertices contains a clique or stable set with many vertices. Now we attach some parameter to every vertex, such as degree. Consider the case a graph with sufficiently many…

Combinatorics · Mathematics 2023-07-18 Jin Sun

We prove a tropical analogue of Cartan's second main theorem for holomorphic curves intersecting hyperplanes in general position--a setting that was not fully resolved by previous tropical Nevanlinna theory. Two versions are obtained. The…

Algebraic Geometry · Mathematics 2026-05-25 Yuting Wang , Tingbin Cao

We prove a Kunneth theorem for the Vietoris-Rips homology and cohomology of a semi-uniform space. We then interpret this result for graphs, where we show that the Kunneth theorem holds for graphs with respect to the strong graph product. We…

Algebraic Topology · Mathematics 2022-09-28 Antonio Rieser , Alejandra Trujillo

In his article [J. Comb. Theory Ser. B 16 (1974), 168-174], Tutte called two graphs $T$-equivalent (i.e., codichromatic) if they have the same Tutte polynomial and showed that graphs $G$ and $G'$ are $T$-equivalent if $G'$ is obtained from…

Combinatorics · Mathematics 2025-01-22 Fengming Dong , Meiqiao Zhang

A path cover is a decomposition of the edges of a graph into edge-disjoint simple paths. Gallai conjectured that every connected $n$-vertex graph has a path cover with at most $\lceil n/2 \rceil$ paths. We prove Gallai's conjecture for…

Combinatorics · Mathematics 2017-06-14 Philipp Kindermann , Lena Schlipf , André Schulz

Roussel and Rubio proved a lemma which is essential in the proof of the Strong Perfect Graph Theorem. We give a new short proof of the main case of this lemma. In this note, we also give a short proof of Hayward's decomposition theorem for…

Combinatorics · Mathematics 2020-12-01 Nicolas Trotignon , Kristina Vušković

The following numerical control over the topological equivalence is proved: two complex polynomials in $n\not= 3$ variables and with isolated singularities are topologically equivalent if one deforms into the other by a continuous family of…

Algebraic Geometry · Mathematics 2007-05-23 Arnaud Bodin , Mihai Tibar

Whitney's 2-Isomorphism Theorem characterises when two graphs have isomorphic cycle matroids. We present an analogue of this theorem for graphs embedded in surfaces by characterising when two graphs in surface have isomorphic…

Combinatorics · Mathematics 2019-10-11 Iain Moffatt , Jaeseong Oh

We discuss, following Mikhalkin, Brugall\'e, and many others, the counting of curves on toric surfaces with prescribed genus, Newton polygon, and intersection pattern with the toric boundary divisor, both at assigned and unassigned points.…

Algebraic Geometry · Mathematics 2025-11-27 Thomas Dedieu

We introduce the notion of resultant of two planar curves in the tropical geometry framework. We prove that the tropicalization of the algebraic resultant can be used to compute the stable intersection of two tropical plane curves. It is…

Algebraic Geometry · Mathematics 2009-11-01 Luis Felipe Tabera

We prove a tropical analogue of the theorem of Hurwitz: a leafless metric graph of genus $g \ge 2$ has at most $12$ automorphisms when $g = 2$; $2^g g!$ automorphisms when $g \ge 3$. These inequalities are optimal; for each genus, we give…

Combinatorics · Mathematics 2021-10-13 Yusuke Nakamura , JuAe Song

One of the characterizing features of tropicalizations of curves in an algebraic torus is that they are balanced. Tevelev and Vogiannou introduced a spherical tropicalization map for spherical homogeneous spaces $G/H$, where $G$ is a…

Algebraic Geometry · Mathematics 2025-05-09 Desmond Coles

In this paper, we establish a derived Torelli Theorem for twisted abelian varieties. Starting from this, we explore the relation between derived isogenies and classical isogenies. We show that two abelian varieties of dimension $\geq 2$ are…

Algebraic Geometry · Mathematics 2025-12-25 Zhiyuan Li , Ziwei Lu , Zhichao Tang

We study a modified notion of Ollivier's coarse Ricci curvature on graphs introduced by Lin, Lu, and Yau in [11]. We establish a rigidity theorem for complete graphs that shows a connected finite simple graph is complete if and only if the…

Combinatorics · Mathematics 2020-11-25 Vincent Bonini , Conor Carroll , Uyen Dinh , Sydney Dye , Joshua Frederick , Erin Pearse

We characterize the graphs $G$ for which their toric ideals $I_G$ are complete intersections. In particular we prove that for a connected graph $G$ such that $I_G$ is complete intersection all of its blocks are bipartite except of at most…

Commutative Algebra · Mathematics 2011-10-06 Christos Tatakis , Apostolos Thoma

An arrangement of finitely many tropical hyperplanes in the tropical torus leads to a notion of `type' data for points, with the underlying unlabeled arrangement giving rise to `coarse type'. It is shown that the decomposition of the…

Combinatorics · Mathematics 2013-01-21 Anton Dochtermann , Michael Joswig , Raman Sanyal

We extend the duality between acyclic orientations and totally cyclic orientations on planar graphs to dualities on graphs on orientable surfaces by introducing boundary acyclic orientations and totally bi-walkable orientations. In…

Combinatorics · Mathematics 2021-09-10 Woo-Seok Jung , Jaeseong Oh

In this paper, second installment in a series of three, we give a correspondence theorem to relate the count of genus $g$ curves in a fixed linear system in an abelian surface to a tropical count. To do this, we relate the linear system…

Algebraic Geometry · Mathematics 2022-02-22 Thomas Blomme

We study characteristics which might distinguish two-graphs by introducing different numerical measures on the collection of graphs on $n$ vertices. Two conjectures are stated, one using these numerical measures and the other using the deck…

Combinatorics · Mathematics 2008-10-20 David M. Duncan , Thomas R. Hoffman , James P. Solazzo

In an earlier paper the first two authors have shown that self-complementary graphs can always be oriented in such a way that the union of the oriented version and its isomorphically oriented complement gives a transitive tournament. We…

Combinatorics · Mathematics 2018-06-05 Attila Sali , Gábor Simonyi , Gábor Tardos