ELA, Volume 15, pp. 274-284, October 2006, abstract.
Irreducible Toeplitz and Hankel Matrices
Karl-Heinz Forster and Bella Nagy
An infinite matrix is called irreducible if its directed
graph is strongly connected. It is proved that an infinite
Toeplitz matrix is irreducible if and only if almost
every finite leading submatrix is irreducible. An infinite
Hankel matrix may be irreducible even if all its finite
leading submatrices are reducible. Irreducibility results
are also obtained in the finite cases.