English
Related papers

Related papers: Generalized Br\'ezin-Gross-Witten tau-function as …

200 papers

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

Sato theory provides a correspondence between solutions to the KP hierarchy and points in an infinite dimensional Grassmannian. In this correspondence, flows generated infinitesimally by powers of the ``shift'' operator give time dependence…

Mathematical Physics · Physics 2009-11-11 Michael Gekhtman , Alex Kasman

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

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 present a review of the spin Hurwitz numbers, which count the ramified coverings with spin structures. They are related to peculiar $Q$ Schur functions, which are actually related to characters of the Sergeev group. This allows one to…

Mathematical Physics · Physics 2021-10-15 A. D. Mironov , A. Yu Morozov , S. M. Natanzon , A. Yu Orlov

Using the matrix-resolvent method and a formula of the second-named author on the $n$-point function for a KP tau-function, we show that the tau-function of an arbitrary solution to the Toda lattice hierarchy is a KP tau-function. We then…

Exactly Solvable and Integrable Systems · Physics 2025-08-12 Di Yang , Jian Zhou

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 generalize the determinant representation of the KP $\tau$ functions to the case of the 2D Toda $\tau$ functions. The generating functions for the weighted Hurwitz numbers are a parametric family of 2D Toda $\tau$ functions; for which we…

Mathematical Physics · Physics 2023-01-18 Xiang-Mao Ding , Xiang Li

For a tau-function of the KP or BKP hierarchy, we introduce the notion of lifting operator and derive an equation connecting the corresponding fermionic two-point function and fermionic one-point function through the lifting operator. This…

Mathematical Physics · Physics 2025-02-14 Shuai Guo , Ce Ji , Chenglang Yang

We extend the old formalism of cut-and-join operators in the theory of Hurwitz $\tau$-functions to description of a wide family of KP-integrable {\it skew} Hurwitz $\tau$-functions, which include, in particular, the newly discovered…

High Energy Physics - Theory · Physics 2023-03-03 A. Mironov , V. Mishnyakov , A. Morozov , A. Popolitov , Wei-Zhong Zhao

We consider special series in ratios of the Schur functions which are defined by integers $\textsc{f}\ge 0$ and $\textsc{e} \le 2$, and also by the set of $3k$ parameters $n_i,q_i,t_i,\,i=1,..., k$. These series may be presented in form of…

Exactly Solvable and Integrable Systems · Physics 2015-01-30 S. M. Natanzon , A. Yu. Orlov

Double Hurwitz numbers enumerating weighted $n$-sheeted branched coverings of the Riemann sphere or, equivalently, weighted paths in the Cayley graph of $S_n$ generated by transpositions are determined by an associated weight generating…

Mathematical Physics · Physics 2018-06-26 Mathieu Guay-Paquet , J. Harnad

This paper is concerned with the construction of the polynomial tau-functions of the symplectic KP (SKP), orthogonal KP (OKP) hierarchies and universal character hierarchy of B-type (BUC hierarchy), which are proved as zero modes of certain…

Exactly Solvable and Integrable Systems · Physics 2023-05-17 Denghui Li , Zhaowen Yan

We investigate the Brezin-Gross-Witten model, a tau-function of the KdV hierarchy, and its natural one-parameter deformation, the generalized Brezin-Gross-Witten tau-function. In particular, we derive the Virasoro constraints, which…

Mathematical Physics · Physics 2021-07-19 Alexander Alexandrov

In this paper we introduce a new family of the KP tau-functions. This family can be described by a deformation of the generalized Kontsevich matrix model. We prove that the simplest representative of this family describes a generating…

Mathematical Physics · Physics 2021-01-12 Alexander Alexandrov

We show that any polynomial tau-function of the s-component KP and the BKP hierarchies can be interpreted as a zero mode of an appropriate combinatorial generating function. As an application, we obtain explicit formulas for all polynomial…

Representation Theory · Mathematics 2021-02-24 Victor G. Kac , Natasha Rozhkovskaya , Johan van de Leur

In this paper, we study combinatorial and asymptotic properties of some interesting rational numbers called the Br\'ezin--Gross--Witten (BGW) numbers, which can be represented as the intersection numbers of psi and Theta classes on the…

Mathematical Physics · Physics 2025-07-21 Jindong Guo , Paul Norbury , Di Yang , Don Zagier

Okounkov's generating function of the double Hurwitz numbers of the Riemann sphere is a hypergeometric tau function of the 2D Toda hierarchy in the sense of Orlov and Scherbin. This tau function turns into a tau function of the lattice KP…

Mathematical Physics · Physics 2022-03-16 Kanehisa Takasaki

The addition formulae for KP $\tau$-functions, when evaluated at lattice points in the KP flow group orbits in the infinite dimensional Sato-Segal-Wilson Grassmannian, give infinite parametric families of solutions to discretizations of the…

Mathematical Physics · Physics 2023-02-24 S. Arthamonov , J. Harnad , J. Hurtubise

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