Author: Adele Zucchi
Publisher: American Mathematical Soc.
ISBN: 0821806262
Category : Mathematics
Languages : en
Pages : 66
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Book Description
In the present paper the author studies the analogue of the class [italic capital]C0 within a class of operators having a functional calculus based on the algebra of bounded holomorphic functions in a finitely connected domain with an analytic boundary. The latter class consists of the operators having the closure of the domain as a spectral set and having no normal direct summands with spectra contained in the boundary of the domain. (If the domain is the disk the preceding class reduces to the class of completely nonunitary contractions.) The basic properties known for the case of the disk, including the model theory, are established. The extension, even the mere construction of the functional calculus, is not routine, in part because it is unknown whether the analogue of Sz.-Nagy's dilation theorem is true in the author's multiply connected setting.
Author: Adele Zucchi
Publisher: American Mathematical Society(RI)
ISBN: 9781470401924
Category : MATHEMATICS
Languages : en
Pages : 66
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Book Description
This book is intended for research mathematicians.
Author: Adele Zucchi
Publisher:
ISBN:
Category :
Languages : en
Pages : 52
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Book Description
Author: Adele Zucci
Publisher:
ISBN:
Category :
Languages : en
Pages : 260
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Book Description
Author: Wenxian Shen
Publisher: American Mathematical Soc.
ISBN: 0821808672
Category : Mathematics
Languages : en
Pages : 111
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Book Description
This volume is devoted to the study of almost automorphic dynamics in differential equations. By making use of techniques from abstract topological dynamics, it is shown that almost automorphy, a notion which was introduced by S. Bochner in 1955, is essential and fundamental in the qualitative study of almost periodic differential equations.
Author: Peter W. Bates
Publisher: American Mathematical Soc.
ISBN: 0821808680
Category : Mathematics
Languages : en
Pages : 145
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Book Description
Extends the theory for normally hyperbolic invariant manifolds to infinite dimensional dynamical systems in a Banach space, thereby providing tools for the study of PDE's and other infinite dimensional equations of evolution. In the process, the authors establish the existence of center-unstable and center-stable manifolds in a neighborhood of the unperturbed compact manifold. No index. Annotation copyrighted by Book News, Inc., Portland, OR
Author: Michael A. Dritschel
Publisher: American Mathematical Soc.
ISBN: 0821806513
Category : Mathematics
Languages : en
Pages : 77
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Book Description
This memoir initiates a model theory-based study of the numerical radius norm. Guided by the abstract model theory of Jim Agler, the authors propose a decomposition for operators that is particularly useful in understanding their properties with respect to the numerical radius norm. Of the topics amenable to investigation with these tools, the following are presented: a complete description of the linear extreme points of the non-matrix (numerical radius) unit ball; several equivalent characterizations of matricial extremals in the unit ball, that is, those members which do not allow a nontrivial extension remaining in the unit ball; and applications to numerical ranges of matrices, including a complete parameterization of all matrices whose numerical ranges are closed disks.
Author: Karl Heinrich Hofmann
Publisher: American Mathematical Soc.
ISBN: 0821806416
Category : Mathematics
Languages : en
Pages : 189
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Book Description
In the structure theory of real Lie groups, there is still information lacking about the exponential function. Most notably, there are no general necessary and sufficient conditions for the exponential function to be surjective. It is surprising that for subsemigroups of Lie groups, the question of the surjectivity of the exponential function can be answered. Under nature reductions setting aside the "group part" of the problem, subsemigroups of Lie groups with surjective exponential function are completely classified and explicitly constructed in this memoir. There are fewer than one would think and the proofs are harder than one would expect, requiring some innovative twists. The main protagonists on the scene are SL(2, R) and its universal covering group, almost abelian solvable Lie groups (ie. vector groups extended by homotheties), and compact Lie groups. This text will also be of interest to those working in algebra and algebraic geometry.
Author: Ching-Chau Yu
Publisher: American Mathematical Soc.
ISBN: 0821807846
Category : Mathematics
Languages : en
Pages : 106
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Book Description
Explores the failure of analytic-hypoellipticity of two partial differential operators. The operators are sums of squares of real analytic vector fields and satisfy Hormander's condition. By reducing to an ordinary differential operator, the author shows the existence of non-linear eigenvalues, which is used to disprove analytic- hypoellipticity of the original operators. No index. Annotation copyrighted by Book News, Inc., Portland, OR
Author: Gregory L. Cherlin
Publisher: American Mathematical Soc.
ISBN: 9780821808368
Category : Mathematics
Languages : en
Pages : 188
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Book Description
In this book, Ramsey theoretic methods introduced by Lachlan are applied to classify the countable homogeneous directed graphs. This is an uncountable collection, and this book presents the first explicit classification result covering an uncountable family. The author's aim is to demonstrate the potential of Lachlan's method for systematic use.
