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Related papers: Diagonal Solutions to the 2-Toda Hierarchy

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We use a double shifted power analog of free fermion fields to introduce current operators, Hamiltonians, and vertex operators which are deformed by two families of parameters and satisfy analogous formulas to the classical case. We show…

Representation Theory · Mathematics 2025-02-19 Daniel Bump , Andrew Hardt , Travis Scrimshaw

We consider the relation of the multi-component 2D Toda hierarchy with matrix orthogonal and biorthogonal polynomials. The multi-graded Hankel reduction of this hierarchy is considered and the corresponding generalized matrix orthogonal…

Exactly Solvable and Integrable Systems · Physics 2010-05-05 Carlos Alvarez-Fernandez , Ulises Fidalgo , Manuel Manas

In this paper we investigate a result of Ueno on the modularity of generating series associated to the zeta functions of binary Hermitian forms previously studied by Elstrodt et al. We improve his result by showing that the generating…

Number Theory · Mathematics 2020-02-25 Jorge Flórez , Cihan Karabulut , An Hoa Vu

In this paper, the authors investigate the case of discrete multiple orthogonal polynomials with two weights on the step line, which satisfy Pearson equations. The discrete multiple orthogonal polynomials in question are expressed in terms…

Classical Analysis and ODEs · Mathematics 2023-07-27 Itsaso Fernández-Irisarri , Manuel Mañas

The generating function of double Hurwitz numbers is known to become a tau function of the Toda hierarchy. The associated Lax and Orlov-Schulman operators turn out to satisfy a set of generalized string equations. These generalized string…

Mathematical Physics · Physics 2015-05-20 Kanehisa Takasaki

The partition function for unitary two matrix models is known to be a double KP tau-function, as well as providing solutions to the two dimensional Toda hierarchy. It is shown how it may also be viewed as a Borel sum regularization of…

Exactly Solvable and Integrable Systems · Physics 2023-08-02 J. Harnad , A. Yu. Orlov

This paper gives a new perspective on how to solve the second-order linear differential equation written in normal form. Extending the argument of the potential to a complex number leads to solving exactly the Schr\"odinger equation when…

Quantum Physics · Physics 2023-01-12 Jamal Benbourenane

The skew-harmonic numbers are the partial sums of the alternating harmonic series, i.e. the expansion of log(2). We evaluate in closed form various power series and numerical series with skew-harmonic numbers. This provides a simultaneous…

Number Theory · Mathematics 2017-01-18 Khristo N. Boyadzhiev

Polynomial-in-time algorithms for computing classical Hurwitz numbers were given in [4] based on the Pandharipande equation. The paritition function of double Hurwitz numbers was proved [21] to satisfy the 2-Toda hierarchy. In this paper,…

Mathematical Physics · Physics 2026-04-30 Xiang Li

Multivariate orthogonal polynomials in $D$ real dimensions are considered from the perspective of the Cholesky factorization of a moment matrix. The approach allows for the construction of corresponding multivariate orthogonal polynomials,…

Classical Analysis and ODEs · Mathematics 2016-08-17 Gerardo Ariznabarreta , Manuel Mañas

We solve direct and inverse problems for two-dimensional (quasi) canonical systems related to exponential polynomials of a specific but sufficiently general type. The approach to the inverse problem in this paper provides an interpretation…

Functional Analysis · Mathematics 2025-10-21 Masatoshi Suzuki

We review the integrable structure of the Dirichlet boundary problem in two dimensions. The solution to the Dirichlet boundary problem for simply-connected case is given through a quasiclassical tau-function, which satisfies the Hirota…

High Energy Physics - Theory · Physics 2007-05-23 A. Marshakov , A. Zabrodin

For a simple Lie algebra $\mathfrak{g}$ and an irreducible faithful representation $\pi$ of $\mathfrak{g}$, we introduce the Schur polynomials of $(\mathfrak{g},\pi)$-type. We then derive the Sato-Zhou type formula for tau functions of the…

Mathematical Physics · Physics 2025-08-29 Mattia Cafasso , Ann du Crest de Villeneuve , Di Yang

We consider the generating series of oriented and non-oriented hypermaps with controlled degrees of vertices, hyperedges and faces. It is well known that these series have natural expansions in terms of Schur and Zonal symmetric functions,…

Combinatorics · Mathematics 2025-11-11 Houcine Ben Dali

In this paper we construct explicit solutions and calculate the corresponding $\tau$-function to the system of Schlesinger equations describing isomonodromy deformations of $2\times 2$ matrix linear ordinary differential equation whose…

Mathematical Physics · Physics 2007-05-23 A. V. Kitaev , D. A. Korotkin

We reconsider the two related problems: distribution of the diagonal elements of a Hermitian n x n matrix of known eigenvalues (Schur) and determination of multiplicities of weights in a given irreducible representation of SU(n) (Kostka).…

Representation Theory · Mathematics 2020-01-23 Robert Coquereaux , Jean-Bernard Zuber

In this paper, we prove some rigidity theorems for the entire 2-convex solutions of 2-Hessian equation in Euclidean space. As an application, we obtain a Bernstein type theorem for global special Lagrangian graphs.

Analysis of PDEs · Mathematics 2018-11-20 Li Chen , Ni Xiang

A unified theory of orthogonal polynomials of a discrete variable is presented through the eigenvalue problem of hermitian matrices of finite or infinite dimensions. It can be considered as a matrix version of exactly solvable Schr\"odinger…

Classical Analysis and ODEs · Mathematics 2008-11-26 Satoru Odake , Ryu Sasaki

We consider an operator of Bernstein for symmetric functions, and give an explicit formula for its action on an arbitrary Schur function. This formula is given in a remarkably simple form when written in terms of some notation based on the…

Combinatorics · Mathematics 2009-02-26 S. R. Carrell , I. P. Goulden

Multiple orthogonality is considered in the realm of a Gauss--Borel factorization problem for a semi-infinite moment matrix. Perfect combinations of weights and a finite Borel measure are constructed in terms of M-Nikishin systems. These…

Classical Analysis and ODEs · Mathematics 2013-11-07 Carlos Álvarez-Fernández , Ulises Fidalgo Prieto , Manuel Mañas