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Related papers: Tropical Hurwitz Numbers

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The paper establishes a formula for enumeration of curves of arbitrary genus in toric surfaces. It turns out that such curves can be counted by means of certain lattice paths in the Newton polygon. The formula was announced earlier in…

Algebraic Geometry · Mathematics 2007-05-23 Grigory Mikhalkin

In 1969, Fulton introduced classical Hurwitz spaces parametrizing simple d-sheeted coverings of the projective line in the algebro-geometric setting. He established the irreducibility of these spaces under the assumption that the…

Algebraic Geometry · Mathematics 2026-05-26 Karl Christ , Xiang He , Ilya Tyomkin

We enumerate complex curves on toric surfaces of any given degree and genus, having a single cusp and nodes as their singularities, and matching appropriately many point constraints. The solution is obtained via tropical enumerative…

Algebraic Geometry · Mathematics 2021-08-31 Yaniv Ganor , Eugenii Shustin

We investigate the problem of counting tropical genus g curves in g-dimensional tropical abelian varieties. For g = 2, 3, we prove that the tropical count matches the count provided by G\"ottsche, Bryan-Leung, and Lange-Sernesi in the…

Algebraic Geometry · Mathematics 2016-06-14 Lars Halvard Halle , Simon Rose

We study tropical line arrangements associated to a three-regular graph $G$ that we refer to as \emph{tropical graph curves}. Roughly speaking, the tropical graph curve associated to $G$, whose genus is $g$, is an arrangement of $2g-2$…

Algebraic Geometry · Mathematics 2026-01-14 Madhusudan Manjunath

The canonical covering maps from Hurwitz varieties to configuration varieties are important in algebraic geometry. The scheme-theoretic fiber above a rational point is commonly connected, in which case it is the spectrum of a Hurwitz number…

Number Theory · Mathematics 2016-08-31 David P. Roberts

We study the real counterpart of double Hurwitz numbers, called real double Hurwitz numbers here. We establish a lower bound for these numbers with respect to their dependence on the distribution of branch points. We use it to prove, under…

Algebraic Geometry · Mathematics 2019-10-14 Johannes Rau

In this paper we find an explicit formula for the number of topologically different ramified coverings $C\to\CP^1$ (C is a compact Riemann surface of genus g) with only one complicated branching point in terms of Hodge integrals over the…

Algebraic Geometry · Mathematics 2009-10-31 Torsten Ekedahl , Sergei Lando , Michael Shapiro , Alek Vainshtein

In this work we study, in greater detail than before, J.H. Conway's topographs for integral binary quadratic forms. These are trees in the plane with regions labeled by integers following a simple pattern. Each topograph can display the…

Number Theory · Mathematics 2025-07-25 Cormac O'Sullivan

Hurwitz numbers count branched covers of the Riemann sphere with specified ramification data, or equivalently, transitive permutation factorizations in the symmetric group with specified cycle types. Monotone Hurwitz numbers count a…

Combinatorics · Mathematics 2019-08-15 I. P. Goulden , Mathieu Guay-Paquet , Jonathan Novak

Hurwitz numbers count branched covers of the Riemann sphere with specified ramification, or equivalently, transitive permutation factorizations in the symmetric group with specified cycle types. Monotone Hurwitz numbers count a restricted…

Combinatorics · Mathematics 2012-10-15 I. P. Goulden , Mathieu Guay-Paquet , Jonathan Novak

The classical Hurwitz numbers which count coverings of a complex curve have an analog when the curve is endowed with a theta characteristic. These "spin Hurwitz numbers", recently studied by Eskin, Okounkov and Pandharipande, are…

Symplectic Geometry · Mathematics 2012-12-12 Junho Lee , Thomas H. Parker

We recover plane curves from their branch points under projection onto a line. Our focus lies on cubics and quartics. These have 6 and 12 branch points respectively. The plane Hurwitz numbers 40 and 120 count the orbits of solutions. We…

Single Hurwitz numbers enumerate branched covers of the Riemann sphere with specified genus, prescribed ramification over infinity, and simple branching elsewhere. They exhibit a remarkably rich structure. In particular, they arise as…

Geometric Topology · Mathematics 2018-11-14 Norman Do , Maksim Karev

In general, Hurwitz numbers count branched covers of the Riemann sphere with prescribed ramification data, or equivalently, factorisations in the symmetric group with prescribed cycle structure data. In this paper, we initiate the study of…

Geometric Topology · Mathematics 2015-11-10 Norman Do , Maksim Karev

In this article, we study the tropical counterpart of the enumeration of rational curves in $\mathbb{CP}^2$ with first order tangency. We use the tropical analogue of the WDVV technique to compute rational tropical plane curves of degree…

Algebraic Geometry · Mathematics 2025-01-29 Anantadulal Paul , Aditya Subramaniam

Recently a new family of enumerative invariants called leaky Hurwitz numbers was introduced by Cavalieri-Markwig-Ranganathan in the context of logarithmic intersection theory. They admit an interpretation via tropical covers where the…

Algebraic Geometry · Mathematics 2026-03-09 Marvin Anas Hahn , Reinier Kramer

Hurwitz numbers with completed cycles are standard Hurwitz numbers with simple branch points replaced by completed cycles. In fact, simple branch points correspond to completed $2$-cycles. Okounkov and Pandharipande have established the…

Combinatorics · Mathematics 2023-11-14 Ricky X. F. Chen , Zhen-Ran Wang

Let $\mathcal{H}$ be a Hurwitz space that parametrises holomorphic maps to $\mathbb{P}^1$. Abramovich, Corti and Vistoli, building on work of Harris and Mumford, describe a compactification $\overline{\mathcal{H}}$ with a natural boundary…

Geometric Topology · Mathematics 2025-07-31 Darragh Glynn

We introduce a tropical geometric framework that allows us to define $\psi$ classes for moduli spaces of tropical curves of arbitrary genus. We prove correspondence theorems between algebraic and tropical $\psi$ classes for some…

Algebraic Geometry · Mathematics 2023-03-22 Renzo Cavalieri , Andreas Gross , Hannah Markwig