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Related papers: Spectral curves for hypergeometric Hurwitz numbers

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We derive the spectral curves for $q$-part double Hurwitz numbers, $r$-spin simple Hurwitz numbers, and arbitrary combinations of these cases, from the analysis of the unstable (0,1)-geometry. We quantize this family of spectral curves and…

Algebraic Geometry · Mathematics 2024-06-26 Motohico Mulase , Sergey Shadrin , Loek Spitz

A multiparametric family of 2D Toda $\tau$-functions of hypergeometric type is shown to provide generating functions for composite, signed Hurwitz numbers that enumerate certain classes of branched coverings of the Riemann sphere and paths…

Mathematical Physics · Physics 2017-02-06 J. Harnad , A. Yu. Orlov

We discuss two elementary constructions for covers with fixed ramification in positive characteristic. As an application, we compute the number of certain classes of covers between projective lines branched at 4 points and obtain…

Algebraic Geometry · Mathematics 2013-05-24 Irene I. Bouw , Leonardo Zapponi

Classical 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. Monotone Hurwitz numbers restrict the…

Geometric Topology · Mathematics 2014-08-19 Norman Do , Alastair Dyer , Daniel V. Mathews

We rewrite the loop equations of the hermitian matrix model, in a way which allows to compute all the correlation functions, to all orders in the topological $1/N^2$ expansion, as residues on an hyperelliptical curve. Those residues, can be…

High Energy Physics - Theory · Physics 2008-11-26 B. Eynard

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

The Hurwitz space is a compactification of the space of rational functions of a given degree. We study the intersection of various strata of this space with its boundary. A study of the cohomology ring of the Hurwitz space then allows us to…

Algebraic Geometry · Mathematics 2007-05-23 Dimitri Zvonkine

We explain how the spectral curve can be extracted from the ${\cal W}$-representation of a matrix model. It emerges from the part of the ${\cal W}$-operator, which is linear in time-variables. A possibility of extracting the spectral curve…

High Energy Physics - Theory · Physics 2023-03-21 A. Mironov , A. Morozov

It has been noticed since around 2007 that certain enumeration problems can be solved when an analytic or algebraic curve is identified. This curve is the key to the problem. In these lectures, a few such examples are presented. One is a…

Quantum Algebra · Mathematics 2025-10-24 Motohico Mulase

We present the matrix models that are the generating functions for branched covers of the complex projective line ramified over $0$, $1$, and $\infty$ (Grotendieck's dessins d'enfants) of fixed genus, degree, and the ramification profile at…

Algebraic Geometry · Mathematics 2020-09-01 Jan Ambjørn , Leonid Chekhov

In this paper we revisit several recent results on monotone and strictly monotone Hurwitz numbers, providing new proofs. In particular, we use various versions of these numbers to discuss methods of derivation of quantum spectral curves…

Mathematical Physics · Physics 2017-08-22 A. Alexandrov , D. Lewanski , S. Shadrin

In this paper, we study a certain type of Hurwitz numbers which count branched covers over the Riemann sphere admitting several branch points with fixed ramification types, one branch point with a fixed number of preimages, and one branch…

Combinatorics · Mathematics 2025-05-19 Zhiyuan Wang , Chenglang Yang

We derive an efficient way to obtain generating functions of bipartite maps of arbitrary genus and boundary length using a spectral curve as initial data for the framework of topological recursion. Based on an earlier result of Chapuy and…

Mathematical Physics · Physics 2025-04-08 Johannes Branahl , Alexander Hock

The 2-matrix model has been introduced to study Ising model on random surfaces. Since then, the link between matrix models and combinatorics of discrete surfaces has strongly tightened. This manuscript aims to investigate these deep links…

High Energy Physics - Theory · Physics 2007-09-20 N. Orantin

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

Hurwitz theory provides a large variety of enumerative problems related to algebraic geometry, mathematical physics, and combinatorics. We give a general framework to approach the large genus asymptotics of Hurwitz theory using only…

Algebraic Geometry · Mathematics 2026-04-15 Davide Accadia , Danilo Lewański , Giulio Ruzza

Symplectic invariants introduced in math-ph/0702045 can be computed for an arbitrary spectral curve. For some examples of spectral curves, those invariants can solve loop equations of matrix integrals, and many problems of enumerative…

Mathematical Physics · Physics 2009-11-30 Bertrand Eynard , Nicolas Orantin

We study a class of scalar, linear, non-local Riemann-Hilbert problems (RHP) involving finite subgroups of PSL(2,C). We associate to such problems a (maybe infinite) root system and describe the relevance of the orbits of the Weyl group in…

Mathematical Physics · Physics 2017-04-03 Gaëtan Borot , Bertrand Eynard , Alexander Weiße

Given a smooth, projective curve $Y$, a point $y_0 \in Y$, a positive integer $n$, and a transitive subgroup $G$ of the symmetric group $S_{d}$ we study smooth, proper families, parameterized by algebraic varieties, of pointed degree $d$…

Algebraic Geometry · Mathematics 2025-10-21 Vassil Kanev

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