Forward and Inverse Problems for Hyperbolic, Elliptic and Mixed Type Equations

Forward and Inverse Problems for Hyperbolic, Elliptic and Mixed Type Equations PDF Author: Alexander G. Megrabov
Publisher: Walter de Gruyter
ISBN: 3110944987
Category : Mathematics
Languages : en
Pages : 244

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Book Description
Inverse problems are an important and rapidly developing direction in mathematics, mathematical physics, differential equations, and various applied technologies (geophysics, optic, tomography, remote sensing, radar-location, etc.). In this monograph direct and inverse problems for partial differential equations are considered. The type of equations focused are hyperbolic, elliptic, and mixed (elliptic-hyperbolic). The direct problems arise as generalizations of problems of scattering plane elastic or acoustic waves from inhomogeneous layer (or from half-space). The inverse problems are those of determination of medium parameters by giving the forms of incident and reflected waves or the vibrations of certain points of the medium. The method of research of all inverse problems is spectral-analytical, consisting in reducing the considered inverse problems to the known inverse problems for the Sturm-Liouville equation or the string equation. Besides the book considers discrete inverse problems. In these problems an arbitrary set of point sources (emissive sources, oscillators, point masses) is determined.

Forward and Inverse Problems for Hyperbolic, Elliptic and Mixed Type Equations

Forward and Inverse Problems for Hyperbolic, Elliptic and Mixed Type Equations PDF Author: Alexander G. Megrabov
Publisher: Walter de Gruyter
ISBN: 3110944987
Category : Mathematics
Languages : en
Pages : 244

Get Book Here

Book Description
Inverse problems are an important and rapidly developing direction in mathematics, mathematical physics, differential equations, and various applied technologies (geophysics, optic, tomography, remote sensing, radar-location, etc.). In this monograph direct and inverse problems for partial differential equations are considered. The type of equations focused are hyperbolic, elliptic, and mixed (elliptic-hyperbolic). The direct problems arise as generalizations of problems of scattering plane elastic or acoustic waves from inhomogeneous layer (or from half-space). The inverse problems are those of determination of medium parameters by giving the forms of incident and reflected waves or the vibrations of certain points of the medium. The method of research of all inverse problems is spectral-analytical, consisting in reducing the considered inverse problems to the known inverse problems for the Sturm-Liouville equation or the string equation. Besides the book considers discrete inverse problems. In these problems an arbitrary set of point sources (emissive sources, oscillators, point masses) is determined.

Forward and Inverse Problems for Hyperbolic, Elliptic, and Mixed Type Equations

Forward and Inverse Problems for Hyperbolic, Elliptic, and Mixed Type Equations PDF Author: A. G. Megrabov
Publisher: V.S.P. International Science
ISBN: 9789067643795
Category : Science
Languages : en
Pages : 230

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Book Description
Inverse problems are an important and rapidly developing direction in mathematics, mathematical physics, differential equations, and various applied technologies (geophysics, optic, tomography, remote sensing, radar-location, etc.). In this monographdirect and inverse problems for partial differential equations are considered. The type of equations focusedare hyperbolic, elliptic, and mixed (elliptic-hyperbolic). The direct problems arise as generalizations of problems of scattering plane elastic or acoustic waves from inhomogeneous layer (or from half-space). The inverse problems are those of determination ofmedium parameters by giving the forms of incident and reflected waves or the vibrations of certain points of the medium. The method of researchof all inverse problems is spectral-analytical, consisting in reducing the considered inverse problems to the known inverse problems for the Sturm-Liouville equation or the string equation. Besides the book considers discrete inverse problems. In these problems an arbitrary set of point sources (emissive sources, oscillators, point masses) is determined.

The Dirichlet Problem for Elliptic-Hyperbolic Equations of Keldysh Type

The Dirichlet Problem for Elliptic-Hyperbolic Equations of Keldysh Type PDF Author: Thomas H. Otway
Publisher: Springer
ISBN: 3642244157
Category : Mathematics
Languages : en
Pages : 219

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Book Description
Partial differential equations of mixed elliptic-hyperbolic type arise in diverse areas of physics and geometry, including fluid and plasma dynamics, optics, cosmology, traffic engineering, projective geometry, geometric variational theory, and the theory of isometric embeddings. And yet even the linear theory of these equations is at a very early stage. This text examines various Dirichlet problems which can be formulated for equations of Keldysh type, one of the two main classes of linear elliptic-hyperbolic equations. Open boundary conditions (in which data are prescribed on only part of the boundary) and closed boundary conditions (in which data are prescribed on the entire boundary) are both considered. Emphasis is on the formulation of boundary conditions for which solutions can be shown to exist in an appropriate function space. Specific applications to plasma physics, optics, and analysis on projective spaces are discussed. (From the preface)

Elliptic, Hyperbolic And Mixed Complex Equations With Parabolic Degeneracy: Including Tricomi-bers And Tricomi-frankl-rassias Problems

Elliptic, Hyperbolic And Mixed Complex Equations With Parabolic Degeneracy: Including Tricomi-bers And Tricomi-frankl-rassias Problems PDF Author: Guo Chun Wen
Publisher: World Scientific
ISBN: 981447228X
Category : Mathematics
Languages : en
Pages : 453

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Book Description
In the recent half-century, many mathematicians have investigated various problems on several equations of mixed type and obtained interesting results, with important applications to gas dynamics. However, the Tricomi problem of general mixed type equations of second order with parabolic degeneracy has not been completely solved, particularly the Tricomi and Frankl problems for general Chaplygin equation in multiply connected domains posed by L Bers, and the existence, regularity of solutions of the above problems for mixed equations with non-smooth degenerate curve in several domains posed by J M Rassias.The method revealed in this book is unlike any other, in which the hyperbolic number and hyperbolic complex function in hyperbolic domains, and the complex number and complex function in elliptic domains are used. The corresponding problems for first order complex equations with singular coefficients are first discussed, and then the problems for second order complex equations are considered, where we pose the new partial derivative notations and complex analytic methods such that the forms of the above first order complex equations in hyperbolic and elliptic domains are wholly identical. In the meantime, the estimates of solutions for the above problems are obtained, hence many open problems including the above Tricomi- Bers and Tricomi-Frankl-Rassias problems can be solved.

Direct Methods of Solving Multidimensional Inverse Hyperbolic Problems

Direct Methods of Solving Multidimensional Inverse Hyperbolic Problems PDF Author: S. I. Kabanikhin
Publisher: Walter de Gruyter
ISBN: 9789067644167
Category : Mathematics
Languages : en
Pages : 196

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Book Description
The authors consider dynamic types of inverse problems in which the additional information is given by the trace of the direct problem on a (usually time-like) surface of the domain. They discuss theoretical and numerical background of the finite-difference scheme inversion, the linearization method, the method of Gel'fand-Levitan-Krein, the boundary control method, and the projection methodand prove theorems of convergence, conditional stability, and other properties of the mentioned methods.

Nonclassical and Inverse Problems for Pseudoparabolic Equations

Nonclassical and Inverse Problems for Pseudoparabolic Equations PDF Author: A. Asanov
Publisher: Walter de Gruyter GmbH & Co KG
ISBN: 3110900149
Category : Mathematics
Languages : en
Pages : 156

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Book Description
The Inverse and Ill-Posed Problems Series is a series of monographs publishing postgraduate level information on inverse and ill-posed problems for an international readership of professional scientists and researchers. The series aims to publish works which involve both theory and applications in, e.g., physics, medicine, geophysics, acoustics, electrodynamics, tomography, and ecology.

Carleman Estimates and Applications to Inverse Problems for Hyperbolic Systems

Carleman Estimates and Applications to Inverse Problems for Hyperbolic Systems PDF Author: Mourad Bellassoued
Publisher: Springer
ISBN: 4431566007
Category : Mathematics
Languages : en
Pages : 267

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Book Description
This book is a self-contained account of the method based on Carleman estimates for inverse problems of determining spatially varying functions of differential equations of the hyperbolic type by non-overdetermining data of solutions. The formulation is different from that of Dirichlet-to-Neumann maps and can often prove the global uniqueness and Lipschitz stability even with a single measurement. These types of inverse problems include coefficient inverse problems of determining physical parameters in inhomogeneous media that appear in many applications related to electromagnetism, elasticity, and related phenomena. Although the methodology was created in 1981 by Bukhgeim and Klibanov, its comprehensive development has been accomplished only recently. In spite of the wide applicability of the method, there are few monographs focusing on combined accounts of Carleman estimates and applications to inverse problems. The aim in this book is to fill that gap. The basic tool is Carleman estimates, the theory of which has been established within a very general framework, so that the method using Carleman estimates for inverse problems is misunderstood as being very difficult. The main purpose of the book is to provide an accessible approach to the methodology. To accomplish that goal, the authors include a direct derivation of Carleman estimates, the derivation being based essentially on elementary calculus working flexibly for various equations. Because the inverse problem depends heavily on respective equations, too general and abstract an approach may not be balanced. Thus a direct and concrete means was chosen not only because it is friendly to readers but also is much more relevant. By practical necessity, there is surely a wide range of inverse problems and the method delineated here can solve them. The intention is for readers to learn that method and then apply it to solving new inverse problems.

Inverse Problems in Partial Differential Equations

Inverse Problems in Partial Differential Equations PDF Author: David L. Colton
Publisher: Soc for Industrial & Applied Math
ISBN:
Category : Mathematics
Languages : en
Pages : 232

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Book Description


Hyperbolic Partial Differential Equations

Hyperbolic Partial Differential Equations PDF Author: Peter D. Lax
Publisher: American Mathematical Soc.
ISBN: 0821835769
Category : Mathematics
Languages : en
Pages : 234

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Book Description
The theory of hyperbolic equations is a large subject, and its applications are many: fluid dynamics and aerodynamics, the theory of elasticity, optics, electromagnetic waves, direct and inverse scattering, and the general theory of relativity. This book is an introduction to most facets of the theory and is an ideal text for a second-year graduate course on the subject. The first part deals with the basic theory: the relation of hyperbolicity to the finite propagation of signals, the concept and role of characteristic surfaces and rays, energy, and energy inequalities. The structure of solutions of equations with constant coefficients is explored with the help of the Fourier and Radon transforms. The existence of solutions of equations with variable coefficients with prescribed initial values is proved using energy inequalities. The propagation of singularities is studied with the help of progressing waves. The second part describes finite difference approximations of hyperbolic equations, presents a streamlined version of the Lax-Phillips scattering theory, and covers basic concepts and results for hyperbolic systems of conservation laws, an active research area today. Four brief appendices sketch topics that are important or amusing, such as Huygens' principle and a theory of mixed initial and boundary value problems. A fifth appendix by Cathleen Morawetz describes a nonstandard energy identity and its uses. -- Back cover.

Hyperbolic Partial Differential Equations and Wave Phenomena

Hyperbolic Partial Differential Equations and Wave Phenomena PDF Author: Mitsuru Ikawa
Publisher: American Mathematical Soc.
ISBN: 9780821810217
Category : Mathematics
Languages : en
Pages : 218

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Book Description
The familiar wave equation is the most fundamental hyperbolic partial differential equation. Other hyperbolic equations, both linear and nonlinear, exhibit many wave-like phenomena. The primary theme of this book is the mathematical investigation of such wave phenomena. The exposition begins with derivations of some wave equations, including waves in an elastic body, such as those observed in connection with earthquakes. Certain existence results are proved early on, allowing the later analysis to concentrate on properties of solutions. The existence of solutions is established using methods from functional analysis. Many of the properties are developed using methods of asymptotic solutions. The last chapter contains an analysis of the decay of the local energy of solutions. This analysis shows, in particular, that in a connected exterior domain, disturbances gradually drift into the distance and the effect of a disturbance in a bounded domain becomes small after sufficient time passes. The book is geared toward a wide audience interested in PDEs. Prerequisite to the text are some real analysis and elementary functional analysis. It would be suitable for use as a text in PDEs or mathematical physics at the advanced undergraduate and graduate level.