Some results on invariant subspaces /

We investigate the structure of operators which are norm

Bibliographic Details
Main Author: Lauric, Vasile, 1966-
Format: Thesis Book
Language:English
Published: [Place of publication not identified] : [publisher not identified] ; 1997.
Subjects:
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Description
Summary:We investigate the structure of operators which are norm
limits of nilpotent operators. In particular, we try to find
some properties which an approximating sequence must have.
We also study a special class of Toeplitz operators and show
that each operator in the class does not commute with any
nonzero compact operator, but a-commutes with some nonzero c
ompact operator. We make a study of the status of the
invariant subspace problem for hyponormal operators. Most
results providing nontrivial invariant subspaces for such
operators involve the geometry of the spectrum. In
particular, we give properties which the spectrum of a
hyponormal operator with no nontrivial invariant subspaces
must have, and we show that certain of these operators have
nontrivial invariant subspaces.
Item Description:Vita.
"Major Subject: Mathematics".
Physical Description:v, 60 leaves ; 28 cm.
Issued also on microfiche from University Microfilms Inc.
Bibliography:Includes bibliographical references: pages 54-59.