A HYPONORMAL TOEPLITZ COMPLETION PROBLEM

We give a brief survey of subnormality and hyponormality of Toeplitz operators on the vector-valued Hardy space of the unit circle. We also solve the following subnormal Toeplitz completion problem: Complete the unspecified rational Toeplitz operators (i.e., the unknown entries are rational Toeplitz operators) of the partial block Toeplitz matrix $$ G: = \left[ \begin{array}{ccc} {{T_{\overline {{\omega _1}} }}}&? \\ ? &{{T_{\overline {{\omega _2}} }}} \end{array} \right]({\omega _1}\,and\,{\omega _2}\,\text{are finite Blaschke products)} $$