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Related papers: Tropical covers of curves and their moduli spaces

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We study the relationship between tropical and classical Hurwitz moduli spaces. Following recent work of Abramovich, Caporaso and Payne, we outline a tropicalization for the moduli space of generalized Hurwitz covers of an arbitrary genus…

Algebraic Geometry · Mathematics 2017-01-20 Renzo Cavalieri , Hannah Markwig , Dhruv Ranganathan

Hurwitz numbers are a weighted count of degree d ramified covers of curves with specified ramification profiles at marked points on the codomain curve. Isomorphism classes of these covers can be included as a dense open set in a moduli…

Algebraic Geometry · Mathematics 2012-11-13 Brian Katz

We introduce the notion of tropical area of a tropical curve defined in an open subset of $\mathbb R^n$. We prove that the number of vertices of a tropical curve is bounded by the area of the curve. The approach is totally elementary yet…

Combinatorics · Mathematics 2020-11-24 Tony Yue Yu

We construct moduli spaces of rational covers of an arbitrary smooth tropical curve in R^r as tropical varieties. They are contained in the balanced fan parametrizing tropical stable maps of the appropriate degree to R^r. The weights of the…

Algebraic Geometry · Mathematics 2017-05-24 Andreas Gathmann , Hannah Markwig , Dennis Ochse

In this paper, we define tropical analogues of real Hurwitz numbers, i.e. numbers of covers of surfaces with compatible involutions satisfying prescribed ramification properties. We prove a correspondence theorem stating the equality of the…

Algebraic Geometry · Mathematics 2015-08-26 Hannah Markwig , Johannes Rau

This is a survey article written for the Jahresberichte der DMV. Tropical geometry can be viewed as an efficient combinatorial tool to study degenerations in algebraic geometry. Abstract tropical curves are essentially metric graphs, and…

Algebraic Geometry · Mathematics 2020-03-23 Hannah Markwig

Hurwitz numbers count genus g, degree d covers of the projective line with fixed branch locus. This equals the degree of a natural branch map defined on the Hurwitz space. In tropical geometry, algebraic curves are replaced by certain…

Algebraic Geometry · Mathematics 2010-07-19 Renzo Cavalieri , Paul Johnson , Hannah Markwig

We extract a system of numerical invariants from logarithmic intersection theory on pluricanonical double ramification cycles, and show that these invariants exhibit a number of properties that are enjoyed by double Hurwitz numbers. Among…

Algebraic Geometry · Mathematics 2025-05-12 Renzo Cavalieri , Hannah Markwig , Dhruv Ranganathan

In recent work, the authors derived a tropical interpretation of monotone and strictly monotone double Hurwitz numbers. In this paper, we apply the technique of tropical flows to this interpretation in order to provide a new proof of the…

Algebraic Geometry · Mathematics 2019-05-08 Marvin Anas Hahn , Danilo Lewanski

We use tropical and nonarchimedean geometry to study the moduli space of genus $0$ stable maps to $\mathbb{P}^1$ relative to two points. This space is exhibited as a tropical compactification in a toric variety. Moreover, the fan of this…

Algebraic Geometry · Mathematics 2017-06-06 Renzo Cavalieri , Hannah Markwig , Dhruv Ranganathan

Tropical geometry is a relatively recent field in mathematics created as a simplified model for certain problems in algebraic geometry. We introduce the definition of abstract and planar tropical curves as well as their properties,…

Algebraic Geometry · Mathematics 2019-01-15 Stanley Wang

We construct and study the tropical moduli space \(\mathcal{M}_3^{\mathrm{trop}}\) of degree-$3$ tropical rational maps \(\mathbb{T}\PP^1 \to \mathbb{T}\PP^1\) up to post-composition. Using a combinatorial description in terms of slope…

Algebraic Geometry · Mathematics 2026-05-18 Tony Shaska , Mohammad-Reza Siadat

Hurwitz numbers count covers of curves satisfying fixed ramification data. Via monodromy representation, this counting problem can be transformed to a problem of counting factorizations in the symmetric group. This and other beautiful…

Combinatorics · Mathematics 2023-12-07 Marvin Anas Hahn , Hannah Markwig

We study rational double Hurwitz cycles, i.e. loci of marked rational stable curves admitting a map to the projective line with assigned ramification profiles over two fixed branch points. Generalizing the phenomenon observed for double…

Algebraic Geometry · Mathematics 2013-05-21 Aaron Bertram , Renzo Cavalieri , Hannah Markwig

Tropical geometry is a piecewise linear "shadow" of algebraic geometry. It allows for the computation of several cohomological invariants of an algebraic variety. In particular, its application to enumerative algebraic geometry led to…

Algebraic Geometry · Mathematics 2012-06-12 Florian Block

We study properties of the tropical double Hurwitz loci defined by Bertram, Cavalieri and Markwig. We show that all such loci are connected in codimension one. If we mark preimages of simple ramification points, then for a generic choice of…

Algebraic Geometry · Mathematics 2015-12-02 Simon Hampe

We study the tropicalization of the moduli space of algebraic spin curves, exhibit its combinatorial stratification and prove that the strata are irreducible. We construct the moduli space of tropical spin curves, prove that it is…

Algebraic Geometry · Mathematics 2019-05-21 Lucia Caporaso , Margarida Melo , Marco Pacini

We construct immersions of trivalent abstract tropical curves in the Euclidean plane and embeddings of all abstract tropical curves in higher dimensional Euclidean space. Since not all curves have an embedding in the plane, we define the…

Combinatorics · Mathematics 2018-06-18 Dustin Cartwright , Andrew Dudzik , Madhusudan Manjunath , Yuan Yao

We give a rigorous definition of tropical fans (the "local building blocks for tropical varieties") and their morphisms. For such a morphism of tropical fans of the same dimension we show that the number of inverse images (counted with…

Algebraic Geometry · Mathematics 2014-01-14 Andreas Gathmann , Michael Kerber , Hannah Markwig

This article discusses a combinatorial extension of tropical intersection theory to spaces given by glueing quotients of partially open convex polyhedral cones by finitely many automorphisms. This extension is done in terms of linear…

Combinatorics · Mathematics 2025-01-10 Diego A. Robayo Bargans
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