1.

Record Nr.

UNIPARTHENOPE000011345

Autore

Davis, Martin <1928- >

Titolo

Computability & unsolvability

Pubbl/distr/stampa

New York [etc.] : McGraw-Hill, 1958

Descrizione fisica

XXV, 210 p. ; 21 cm

Disciplina

517.5

Collocazione

517.5/102

Lingua di pubblicazione

Inglese

Formato

Materiale a stampa

Livello bibliografico

Monografia

2.

Record Nr.

UNINA9910146292203321

Autore

Neuberger J. W (John W.), <1934->

Titolo

Sobolev gradients and differential equations / / J. W. Neuberger

Pubbl/distr/stampa

Berlin, Germany ; ; New York, New York : , : Springer, , [1997]

©1997

ISBN

3-540-69594-X

Edizione

[1st ed. 1997.]

Descrizione fisica

1 online resource (VIII, 152 p.)

Collana

Lecture Notes in Mathematics, , 0075-8434 ; ; 1670

Classificazione

65N30

35A15

Disciplina

515/.353

Soggetti

Differential equations - Numerical solutions

Sobolev gradients

Lingua di pubblicazione

Inglese

Formato

Materiale a stampa

Livello bibliografico

Monografia

Note generali

Bibliographic Level Mode of Issuance: Monograph

Nota di bibliografia

Includes bibliographical references (pages [145]-149) and index.

Nota di contenuto

Several gradients -- Comparison of two gradients -- Continuous steepest descent in Hilbert space: Linear case -- Continuous steepest descent in Hilbert space: Nonlinear case -- Orthogonal projections, Adjoints and Laplacians -- Introducing boundary conditions --



Newton's method in the context of Sobolev gradients -- Finite difference setting: the inner product case -- Sobolev gradients for weak solutions: Function space case -- Sobolev gradients in non-inner product spaces: Introduction -- The superconductivity equations of Ginzburg-Landau -- Minimal surfaces -- Flow problems and non-inner product Sobolev spaces -- Foliations as a guide to boundary conditions -- Some related iterative methods for differential equations -- A related analytic iteration method -- Steepest descent for conservation equations -- A sample computer code with notes.

Sommario/riassunto

A Sobolev gradient of a real-valued functional is a gradient of that functional taken relative to the underlying Sobolev norm. This book shows how descent methods using such gradients allow a unified treatment of a wide variety of problems in differential equations. Equal emphasis is placed on numerical and theoretical matters. Several concrete applications are made to illustrate the method. These applications include (1) Ginzburg-Landau functionals of superconductivity, (2) problems of transonic flow in which type depends locally on nonlinearities, and (3) minimal surface problems. Sobolev gradient constructions rely on a study of orthogonal projections onto graphs of closed densely defined linear transformations from one Hilbert space to another. These developments use work of Weyl, von Neumann and Beurling.