This is a continuation of the papers [4] of Bleher and Fokin and [5] of
Bleher and Liechty, in which the large n asymptotics is obtained for the
partition function Zn​ of the six-vertex model with domain wall boundary
conditions in the disordered and ferroelectric phases, respectively. In the
present paper we obtain the large n asymptotics of Zn​ on the critical line
between these two phases.Comment: 22 pages, 6 figures, to appear in the Journal of Statistical Physic