Crystallization of deformed Virasoro algebra, Ding-Iohara-Miki algebra and 5D AGT correspondence
Yusuke Ohkubo, Hidetoshi Awata, Hiroki Fujino
TL;DR
The paper analyzes the $q \to 0$ crystallization of the deformed Virasoro algebra and the level-$N$ representation of the Ding-Iohara-Miki algebra, linking these limits to Hall-Littlewood functions and enabling explicit AGT-related results. By constructing a free-field realization with bosons and identifying PBW-type vectors with Hall-Littlewood functions, the authors show the disappearance of singular vectors and derive a crystallized Nekrasov partition function that equals the norm of the crystallized Whittaker vector. For $N=1$ and $N=2$, they demonstrate that the crystallized PBW-type vectors form bases, develop generalized Hall-Littlewood functions and integral forms, and obtain explicit 4-point correlation functions consistent with a crystallized 5D AGT picture. The work provides a tractable, zero-temperature–like instantiation of AGT where Nekrasov factors reduce to Hall-Littlewood–based expressions, offering a foundation for extending crystallization to higher $N$ and other scaling limits with potential physical and mathematical insights.
Abstract
In this paper, we consider the $q \rightarrow 0$ limit of the deformed Virasoro algebra and that of the level 1, 2 representation of Ding-Iohara-Miki algebra. Moreover, 5D AGT correspondence at this limit is discussed. This specialization corresponds to the limit from Macdonalds functions to Hall-Littlewood functions. Using the theory of Hall-Littlewood functions, some problems are solved. For example, the simplest case of 5D AGT conjectures is proven at this limit, and we obtain a formula for the 4-point correlation function of a certain operator.
