Title

Login

Join

Book's by Il Bong Jung

Covers

List

Unbounded Weighted Composition Operators in L2-Spaces

By: Piotr Budzyński,Zenon Jabłoński,Il Bong Jung,Jan Stochel

Write a review Read reviews Take a Quiz Solve Book Puzzle

Unbounded Weighted Composition Operators in L2-Spaces

By: Piotr Budzyński,Zenon Jabłoński,Il Bong Jung,Jan Stochel

This book establishes the foundations of the theory of bounded and unbounded weighted composition operators in L2-spaces. It develops the theory in full generality, meaning that the corresponding composition operators are not assumed to be well defined. A variety of seminormality properties of unbounded weighted composition operators are characterized. The first-ever criteria for subnormality of unbounded weighted composition operators are provided and the subtle interplay between the classical moment problem, graph theory and the injectivity problem for weighted composition operators is revealed. The relationships between weighted composition operators and the corresponding multiplication and composition operators are investigated. The optimality of the obtained results is illustrated by a variety of examples, including those of discrete and continuous types. The book is primarily aimed at researchers in single or multivariable operator theory.

Average ratings

N/A

5

0%

4

0%

3

0%

2

0%

1

0%

Solve jigsaw puzzle

Age

Page Count

189

Publisher

Springer

Published Date

ISBN 10

3319740393

ISBN 13

9783319740393

Weighted Shifts on Directed Trees

By: Zenon Jan Jablónski,Il Bong Jung,Jan Stochel

Write a review Read reviews Take a Quiz Solve Book Puzzle

Weighted Shifts on Directed Trees

By: Zenon Jan Jablónski,Il Bong Jung,Jan Stochel

A new class of (not necessarily bounded) operators related to (mainly infinite) directed trees is introduced and investigated. Operators in question are to be considered as a generalization of classical weighted shifts, on the one hand, and of weighted adjacency operators, on the other; they are called weighted shifts on directed trees. The basic properties of such operators, including closedness, adjoints, polar decomposition and moduli are studied. Circularity and the Fredholmness of weighted shifts on directed trees are discussed. The relationships between domains of a weighted shift on a directed tree and its adjoint are described. Hyponormality, cohyponormality, subnormality and complete hyperexpansivity of such operators are entirely characterized in terms of their weights. Related questions that arose during the study of the topic are solved as well.

Average ratings

N/A

5

0%

4

0%

3

0%

2

0%

1

0%

Solve jigsaw puzzle

Age

Page Count

122

Publisher

American Mathematical Soc.

Published Date

ISBN 10

0821868683

ISBN 13

9780821868683