arXiv subjects

Gurvan Mével

Publications and source records attributed to Gurvan Mével.

5 recordsLinked to original sources

arXiv2026

Non-existence of separating morphisms of low degree

A separating curve is a real curve whose real part disconnects its complex part. It also admits totally real morphisms to the projective line, and the separating gonality is the minimal possible degree for such morphisms. The separating gonality is bounded from below by the number of connected components of the real part of the curve. In this paper, we build on a strategy of Manzaroli to improve this lower bound for some curves embedded in the projective plane or in a Hirzebruch surface.

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arXiv2026

Refined invariants for Abelian surfaces: between polynomiality and modularity

Tropical refined invariants for toric surfaces, introduced Block and G{ö}ttsche, are obtained couting tropical curves with a Laurent polynomial multiplicity. Brugall{é} and Jaramillo-Puentes then exhibited a polynomial behavior of the coefficients of this Laurent polynomial, seen as function on the curve degree. The authors provided explicit formula for small genus, involving quasi-modular forms. Inspired by the toric setting, the first-named author defined refined invariants for abelian surfaces and extended the polynomiality result. In this paper, we further study this regularity for abelian surfaces, providing explicit formulas involving quasi-modular forms. This resonates with the small genus cases of the toric setting.

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arXiv2025

Asymptotic computations of tropical refined invariants in genus 0 and 1

Block and Göttsche introduced a Laurent polynomial multiplicity to count tropical curves. Itenberg and Mikhalkin then showed that this multiplicity leads to invariant counts called tropical refined invariants. Recently, Brugallé and Jaramillo-Puentes studied the polynomiality properties of the coefficients of these invariants and showed that for fixed genus g, the coefficients ultimately coincide with polynomials in the homology class of the curves we look at. We call the generating series of these polynomials asymptotic refined invariant. In genus 0, the asymptotic refined invariant has been computed by the second author in the h-transverse case. In this paper, we give a new proof of the formula for the asymptotic refined invariant for g = 0 using variations on the floor diagram algorithm. This technique allows also to compute the asymptotic refined invariant for g = 1. The result exhibits surprising regularity properties related to the generating series of partition numbers and quasi-modular forms.

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arXiv2024

Combinatorial Göttsche-Schroeter invariants in any genus

Göttsche-Schroeter invariants are a genus 0 extension of Block-Göttsche invariants. They interpolate between Welschinger invariants involving pairs of complex conjugated points and genus 0 descendant Gromov-Witten invariants. They can be computed by a floor diagram algorithm. In this paper, we show that this floor diagrams recipe actually leads to some invariants in any genus. This generalizes Göttsche-Schroter invariant in higher genus in a combinatorial way. We then prove some polynomiality result and establish a link with invariants defined by Shustin and Sinichkin. We provide many examples. In particular, we conjecture that these combinatorial invariants satisfy the Abramovich-Bertram formula.

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arXiv2023

Universal polynomials for tropical refined invariants in genus 0

In 2022, Brugall{é} and Jaramillo-Puentes showed that the coefficients of small codegree of the tropical refined invariant are polynomial in the Newton polygon. This raised the question of the existence of universal polynomials giving these coefficients, i.e. polynomials depending only on the genus and the codegree, and with variables the combinatorial data of the Newton polygon.In this paper we show that such universal polynomials exist for rational enumeration, and we give an explicit formula. The proof relies on the manipulation of floor diagrams.

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