Partial Differential Equations V: Asymptotic Methods for Partial Differential Equations (Encyclopaedia of Mathematical Sciences) (v. 5) pdf epub fb2

Partial Differential Equations V: Asymptotic Methods for Partial Differential Equations (Encyclopaedia of Mathematical Sciences) (v. 5) by - pdf epub fb2

Partial Differential Equations V: Asymptotic Methods for Partial Differential Equations (Encyclopaedia of Mathematical Sciences) (v. 5) Author: -
Title: Partial Differential Equations V: Asymptotic Methods for Partial Differential Equations (Encyclopaedia of Mathematical Sciences) (v. 5)
ISBN: 3540533710
ISBN13: 978-3540615118
Other Formats: rtf azw docx txt
Pages: 247 pages
Publisher: Springer; 1999 edition (December 18, 2001)
Language: English
Category: Science & Math
Size PDF version: 1692 kb
Size EPUB version: 1813 kb
Subcategory: Mathematics




In this paper we shall discuss the construction of formal short-wave asymp­ totic solutions of problems of mathematical physics. The topic is very broad. It can somewhat conveniently be divided into three parts: 1. Finding the short-wave asymptotics of a rather narrow class of problems, which admit a solution in an explicit form, via formulas that represent this solution. 2. Finding formal asymptotic solutions of equations that describe wave processes by basing them on some ansatz or other. We explain what 2 means. Giving an ansatz is knowing how to give a formula for the desired asymptotic solution in the form of a series or some expression containing a series, where the analytic nature of the terms of these series is indicated up to functions and coefficients that are undetermined at the first stage of consideration. The second stage is to determine these functions and coefficients using a direct substitution of the ansatz in the equation, the boundary conditions and the initial conditions. Sometimes it is necessary to use different ansiitze in different domains, and in the overlapping parts of these domains the formal asymptotic solutions must be asymptotically equivalent (the method of matched asymptotic expansions). The basis for success in the search for formal asymptotic solutions is a suitable choice of ansiitze. The study of the asymptotics of explicit solutions of special model problems allows us to "surmise" what the correct ansiitze are for the general solution.