KdV solves BKP.

Alexandrov, Alexander · Proc Natl Acad Sci U S A · 2021

Where this comes from

Abstract

In this note, we prove that any τ-function of the Korteweg-de Vries (KdV) hierarchy also solves the type B Kadomtsev-Petviashvili (BKP) hierarchy after a simple rescaling of times.