Hyperexpansive completion problem via alternating sequences; an application to subnormality (Q2431165)

This paper provides a solution of the completion problem for completely hyperexpansive weighted shifts in terms of positivity of matrices attached to the sequence of the first \(m+1\) weights. Explicit solutions are given for sequences with at most six terms. Applications to the subnormal completion problem are given. These results are obtained by a new method using truncations of completely alternating sequences, for which an equivalent characterization is obtained.