Operators That Commute with Slant Toeplitz Operators
1 Department of Applied Mathematics, National Sun Yat-Sen University, Kaohsiung, Taiwan
2 Department of Information Technology, Meiho Institute of Technology, Pington, Taiwan
Correspondence: Correspondence to be sent to: hom{at}mail.math.nsysu.edu.tw
Let
be a separable Hilbert space and
be an orthonormal basis in
. A bounded operator
is called the slant Toeplitz operator if
, where cn is the nth Fourier coefficient of a bounded Lebesgue measurable function
on the unit circle
. It has been shown [9], with some assumption on the smoothness and the zeros of
, that
is similar to either the constant multiple of a shift or to the constant multiple of the direct sum of a shift and a rank one unitary, with infinite multiplicity. These results, together with the theory of shifts (e.g., in [11]), allows us to identify all bounded operators on
commuting with such
.