Korepin V. E., Slavnov N. A.
The Riemann-Hilbert problem  associated with the quantum Nonlinear 
Schrodinger equation 
(51K, LaTeX)

ABSTRACT.  We consider the dynamical correlation functions 
of the quantum Nonlinear Schrodinger equation.  In a previous paper  
we found that the dynamical correlation functions can be described by 
the vacuum expectation value of an operator-valued Fredholm 
determinant.  In this paper we show that a Riemann--Hilbert problem 
can be associated with this Fredholm determinant.  This 
Riemann--Hilbert problem formulation permits us to  write down 
completely integrable equations for the Fredholm determinant and to 
perform  an asymptotic analysis for the correlation function.