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Related papers: Combinatorics of pruned Hurwitz numbers

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Edge-contraction operations form an effective tool in various graph enumeration problems, such as counting Grothendieck's dessins d'enfants and simple and double Hurwitz numbers. These counting problems can be solved by a mechanism known as…

Algebraic Geometry · Mathematics 2019-08-16 Olivia Dumitrescu , Motohico Mulase

This is the first of two papers on the uniform asymptotics for real double Hurwitz numbers with triple ramification. Real double Hurwitz numbers with triple ramification count the number of real ramified coverings of the complex projective…

Algebraic Geometry · Mathematics 2026-02-05 Yanqiao Ding , Kui Li , Huan Liu , Dongfeng Yan

The main goal of the paper is to present a new approach via Hurwitz numbers to Kontsevich's combinatorial/matrix model for the intersection theory of the moduli space of curves. A secondary goal is to present an exposition of the circle of…

Algebraic Geometry · Mathematics 2007-05-23 Andrei Okounkov , Rahul Pandharipande

In this paper we study relations between intersection numbers on moduli spaces of curves and Hurwitz numbers. First, we prove two formulas expressing Hurwitz numbers of (generalized) polynomials via intersections on moduli spaces of curves.…

Algebraic Geometry · Mathematics 2010-10-04 Sergei Shadrin

We introduce a family of polynomials, which arise in three distinct ways: in the large $N$ expansion of a matrix integral, as a weighted enumeration of factorisations of permutations, and via the topological recursion. More explicitly, we…

Combinatorics · Mathematics 2025-07-02 Xavier Coulter , Norman Do , Ellena Moskovsky

Hurwitz numbers, which count certain covers of the projective line (or, equivalently, factorizations of permuations into transpositions), have been extensively studied for over a century. The Gromov-Witten potential F of a point, the…

Algebraic Geometry · Mathematics 2007-05-23 Ian Goulden , David Jackson , Ravi Vakil

As the real counterpart of double Hurwitz number, the real double Hurwitz number depends on the distribution of real branch points. We consider the problem of asymptotic growth of real and complex double Hurwitz numbers. We provide a lower…

Algebraic Geometry · Mathematics 2023-03-08 Yanqiao Ding

This article introduces mixed double Hurwitz numbers, which interpolate combinatorially between the classical double Hurwitz numbers studied by Okounkov and the monotone double Hurwitz numbers introduced recently by Goulden, Guay-Paquet and…

Combinatorics · Mathematics 2016-04-21 I. P. Goulden , Mathieu Guay-Paquet , Jonathan Novak

The construction of hypergeometric $2D$ Toda $\tau$-functions as generating functions for weighted Hurwitz numbers is extended to multispecies families. Both the enumerative geometrical significance of multispecies weighted Hurwitz numbers,…

Mathematical Physics · Physics 2018-06-26 J. Harnad

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 extend a holomorphic projection argument of our earlier work to prove a novel divisibility result for non-holomorphic congruences of Hurwitz class numbers. This result allows us to establish Ramanujan-type congruences for Hurwitz class…

Number Theory · Mathematics 2022-03-23 Olivia Beckwith , Martin Raum , Olav Richter

The main purpose of this survey is to provide an introduction, algebro-topological in nature, to Hirzebuch-type inequalities for plane curve arrangements in the complex projective plane. These inequalities gain more and more interest due to…

Combinatorics · Mathematics 2021-01-18 Piotr Pokora

The KP and 2D Toda tau-functions of hypergeometric type that serve as generating functions for weighted single and double Hurwitz numbers are related to the topological recursion programme. A graphical representation of such weighted…

Mathematical Physics · Physics 2021-03-04 A. Alexandrov , G. Chapuy , B. Eynard , J. Harnad

We consider weighted double Hurwitz numbers, with the weight given by arbitrary rational function times an exponent of the completed cycles. Both special singularities are arbitrary, with the lengths of cycles controlled by formal…

Mathematical Physics · Physics 2025-01-13 Boris Bychkov , Petr Dunin-Barkowski , Maxim Kazarian , Sergey Shadrin

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 propose a new, conjectural recursion solution for Hurwitz numbers at all genera. This conjecture is based on recent progress in solving type B topological string theory on the mirrors of toric Calabi-Yau manifolds, which we briefly…

Algebraic Geometry · Mathematics 2008-12-04 Vincent Bouchard , Marcos Marino

The main object of this paper is to investigate a new class of the generalized Hurwitz type poly-Bernoulli numbers and polynomials from which we derive some algorithms for evaluating the Hurwitz type poly-Bernoulli numbers and polynomials.…

Combinatorics · Mathematics 2023-10-05 Mohamed Amine Boutiche , Mohamed Mechacha , Mourad Rahmani

Multiparametric families of hypergeometric $\tau$-functions of KP or Toda type serve as generating functions for weighted Hurwitz numbers, providing weighted enumerations of branched covers of the Riemann sphere. A graphical interpretation…

Mathematical Physics · Physics 2019-07-02 A. Alexandrov , G. Chapuy , B. Eynard , J. Harnad

We prove that single $G$-weighted $\mathfrak{b}$-Hurwitz numbers with internal faces are computed by refined topological recursion on a rational spectral curve, for certain rational weights $G$. Consequently, the $\mathfrak{b}$-Hurwitz…

Combinatorics · Mathematics 2026-03-17 Nitin Kumar Chidambaram , Maciej Dołęga , Kento Osuga

We give a bijective proof of Hurwitz formula for the number of simple branched coverings of the sphere by itself. Our approach extends to double Hurwitz numbers and yields new properties for them. In particular we prove for double Hurwitz…

Combinatorics · Mathematics 2014-10-27 Enrica Duchi , Dominique Poulalhon , Gilles Schaeffer