Abstract

In their recent inspiring paper, Mironov and Morozov claim a surprisingly simple expansion formula for the Kontsevich-Witten tau-function in terms of the Schur Q-functions. Here we provide a similar description for the Brézin-Gross-Witten tau-function. Moreover, we identify both tau-functions of the KdV hierarchy, which describe intersection numbers on the moduli spaces of punctured Riemann surfaces, with the hypergeometric solutions of the BKP hierarchy.

Highlights

  • In this paper we consider1 a Schur Q-function expansion of the BGW tau-function

  • We provide a similar description for the Brézin-Gross-Witten tau-function. We identify both tau-functions of the KdV hierarchy, which describe intersection numbers on the moduli spaces of punctured Riemann surfaces, with the hypergeometric solutions of the BKP hierarchy

  • After the first version of this paper was posted on the arXiv, the author has proven [4] that any solution of the KdV hierarchy solves the BKP hierarchy, or symbolically

Read more

Summary

Intersection numbers and their generating functions

Denote by Mg,n the Deligne-Mumford compactification of the moduli space of all compact Riemann surfaces of genus g with n distinct marked points It is a non-singular complex orbifold of dimension 3g − 3 + n. An interesting family of such intersection numbers was recently considered by Norbury [31] He introduced Θ-classes, Θg,n ∈ H4g−4+2n(Mg,n), see [32, section 2] for the definition. We refer the reader to [31, 32] for a detailed description Both KW and BGW tau-functions can be described by matrix models. The BGW tau-function in the Miwa parametrization is given by the unitary matrix integral. It has another integral description [27], similar to the Kontsevich integral (2.12), see section 2.3 below. KdV integrability of the BGW model follows from this description

Heisenberg-Virasoro constraints and cut-and-join description
Generalized Brézin-Gross-Witten model
Q-Schur expansion of the KW and BGW tau-functions
BKP hierarchy
Symmetries of BKP
Hypergeometric solutions of BKP hierarchy
Result
Miller-Morita-Mumford classes

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.