2026/03/02 by Zongyao Feng, Lumin Geng, Chao-Zhong Wu · 1 voice
Physics and Astronomy · #nlin.SI
paper · pdf · doi:10.1007/s11005-026-02104-5
arxiv published 2026/03/02 · arxiv updated 2026/06/22
A KP-mKP hierarchy was introduced recently via pseudo-differential operators containing two derivations. In this paper, for the KP-mKP hierarchy we derive a class of (differential) Fay identities and construct a series of additional symmetries. Moreover, the additional symmetries are represented as certain linear actions on the tau functions of the hierarchy, with the help of the Adler-Shiota-van Moerbeke formula. As an application, we reprove the Virasoro constraints to the tau functions of the Burgers-KdV hierarchy, and such results are generalized to its higher order extensions regarded as reductions of the KP-mKP hierarchy.