Self-adjoint Toeplitz operators have purely absolutely continuous spectrum. For Toeplitz
operators
with piecewise continuous symbols, we suggest a further spectral
classification determined by propagation properties of the operator
, that is, by
the behavior of
for
.
It turns out that the spectrum is naturally partitioned into three disjoint
subsets:
thick,
thin and
mixed spectra. On the thick spectrum, the propagation
properties are modeled by the continuous part of the symbol, whereas on the thin
spectrum, the model operator is determined by the jumps of the symbol.
On the mixed spectrum, these two types of the asymptotic evolution of
coexist. This classification is justified in the framework of scattering theory. We prove
the existence of wave operators that relate the model operators with the Toeplitz
operator
.
The ranges of these wave operators are pairwise orthogonal, and their orthogonal
sum exhausts the whole space; i.e., the set of these wave operators is asymptotically
complete.