English
Related papers

Related papers: Hurwitz numbers and BKP hierarchy

200 papers

We compute the number of (weak) equivalence classes of branched covers from a surface of genus g to the sphere, with 3 branching points, degree 2k, and local degrees over the branching points of the form (2,...,2), (2h+1,1,2,...,2),…

Geometric Topology · Mathematics 2018-09-06 Carlo Petronio

We continue our computation, using a combinatorial method based on Gronthendieck's dessins d'enfant, of the number of (weak) equivalence classes of surface branched covers matching certain specific branch data. In this note we concentrate…

Geometric Topology · Mathematics 2018-07-31 Carlo Petronio

This manuscript recounts some of the author's contributions to algebraic and enumerative combinatorics. We have focused on two types of generalizations of bipartite maps, which are bipartite graphs embedded on surfaces. Maps are known to…

Combinatorics · Mathematics 2023-02-14 Valentin Bonzom

In this paper, we prove that the generalized Br\'ezin-Gross-Witten tau-function is a hypergeometric solution of the BKP hierarchy with simple weight generating function. We claim that it describes a spin version of the strictly monotone…

Mathematical Physics · Physics 2022-12-13 Alexander Alexandrov

Partition functions often become \tau-functions of integrable hierarchies, if they are considered dependent on infinite sets of parameters called time variables. The Hurwitz partition functions Z = \sum_R…

High Energy Physics - Theory · Physics 2015-05-27 A. Alexandrov , A. Mironov , A. Morozov , S. Natanzon

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

Mathematical Physics · Physics 2016-11-01 J. Harnad

Parametric families in the centre ${\bf Z}({\bf C}[S_n])$ of the group algebra of the symmetric group are obtained by identifying the indeterminates in the generating function for Macdonald polynomials as commuting Jucys-Murphy elements.…

Mathematical Physics · Physics 2017-01-30 J. Harnad

The basis elements spanning the Sato Grassmannian element corresponding to the KP $\tau$-function that serves as generating function for rationally weighted Hurwitz numbers are shown to be Meijer $G$-functions. Using their Mellin-Barnes…

Mathematical Physics · Physics 2021-11-30 J. Harnad

We introduce and investigate a family of tau-functions of the 2D Toda hierarchy, which is a natural generalization of the hypergeometric family associated with Hurwitz numbers. For this family we prove a skew Schur function expansion…

Mathematical Physics · Physics 2025-11-06 Alexander Alexandrov

There is now a renewed interest to the Hurwitz tau-function, counting the isomorphism classes of Belyi pairs, arising in the study of equilateral triangulations and Grothiendicks's dessins d'enfant. It is distinguished by belonging to a…

High Energy Physics - Theory · Physics 2014-11-25 A. Alexandrov , A. Mironov , A. Morozov , S. Natanzon

We study a $b$-deformation of monotone Hurwitz numbers, obtained by deforming Schur functions into Jack symmetric functions. We give an evolution equation for this model and derive from it Virasoro constraints, thereby proving a conjecture…

Combinatorics · Mathematics 2023-12-18 Valentin Bonzom , Guillaume Chapuy , Maciej Dołęga

Hurwitz numbers enumerate branched morphisms between Riemann surfaces. For a fixed elliptic target, Hurwitz numbers are intimately related to mirror symmetry following work of Dijkgraaf. In recent work of Chapuy and Dolega a new variant of…

Combinatorics · Mathematics 2024-10-28 Marvin Anas Hahn , Hannah Markwig

Double Hurwitz numbers enumerate branched covers of $\mathbb{CP}^1$ with prescribed ramification over two points and simple ramification elsewhere. In contrast to the single case, their underlying geometry is not well understood. In…

Algebraic Geometry · Mathematics 2023-07-07 Gaëtan Borot , Norman Do , Maksim Karev , Danilo Lewański , Ellena Moskovsky

In this paper, we aim to provide an accessible survey to various formulae for calculating single Hurwitz numbers. Single Hurwitz numbers count certain classes of meromorphic functions on complex algebraic curves and have a rich geometric…

Algebraic Geometry · Mathematics 2020-02-25 Jared Ongaro

This is an overview of recent results on the use of 2D Toda $\tau$-functions as generating functions for multiparametric families of weighted Hurwitz numbers. The Bose-Fermi equivalence composed with the characteristic map provides an…

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

We study spin Hurwitz numbers, which count ramified covers of the Riemann sphere with a sign coming from a theta characteristic. These numbers are known to be related to Gromov-Witten theory of K\"ahler surfaces and to representation theory…

Mathematical Physics · Physics 2024-06-19 Alessandro Giacchetto , Reinier Kramer , Danilo Lewański

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

Branched covers of the complex projective line ramified over $0,1$ and $\infty$ (Grothendieck's {\em dessins d'enfant}) of fixed genus and degree are effectively enumerated. More precisely, branched covers of a given ramification profile…

Combinatorics · Mathematics 2014-03-25 Peter Zograf

Hurwitz numbers are the Laurent coefficients of an elliptic function $\wp(u)$ of cyclotomic type, and they are natural generalization of the Bernoulli numbers. This paper gives new generalization of Bernoulli and Hurwitz numbers for higher…

Number Theory · Mathematics 2007-05-23 Yoshihiro Ônishi

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