Helena
Mascarenhas
(Instituto Superior Técnico, UTL and CEAF)
" Spectral
properties of variable coefficient Toeplitz matrices "
Abstract. Variable
Toeplitz matrices, a generalization of the finite sections of a
Toeplitz operator, have received increasing interest in recent years.
They also appear under different names: generalized locally Toeplitz
matrices, generalized convolutions or twisted Toeplitz matrices,
with applications to discretized PDE, probability theory and
statiscal mechanics. We will focus on sequences of variable-
coefficient Toeplitz matrices with symbol on a class of the Wiener
type. Using C*- algebras techniques, we will discuss the asymptotic
behaviour of singular values, condition numbers and pseudospectrum, as
well as the analogon of Fredolhm theory for sequences.
