XXZ SCALAR PRODUCTS, MIWA VARIABLES AND DISCRETE KP

We revisit the quantum/classical integrable model correspondence in the context of inhomogeneous finite length XXZ spin- ½ chains with periodic boundary conditions and show that the Bethe scalar product of an arbitrary state and a Bethe eigenstate is a discrete KP τ-function. The continuous Miwa variables of discrete KP are the rapidities of the arbitrary state.