Applied Asymptotic Analysis
Applied Asymptotic Analysis, volume 75 of the Graduate Studies in Mathematics series published by the American Mathematical Society, is a textbook
intended for graduate students or advanced undergraduate students. It was originally developed as a text for the course Math 557, Methods of Applied Mathematics II: Asymptotic Analysis, which is part of the "core" of the Applied and Interdisciplinary Mathematics (AIM) graduate program at the University of Michigan.
Update Log
Here is a current list of corrections to the text.
Chapter 2
- Section 2.1 (Review of basic methods), page 51. The index \(k\) of the product in equation (2.5) should start at \(k=1\) instead of \(k=0\). [JW]
- Section 2.3 (Elementary generalizations of Watson's Lemma), page 58. Line 7 should read instead "Taking \(\sigma=2\), we then have the result". [SB]
Chapter 3
- Section 3.4 (Contributions from interior maxima), page 69. The first term in the numerator of the last displayed equation should be \(5R'''(t_{\mathrm{max}})^2\) instead of \(5R'''(t_\mathrm{max})\). [SB]
- Section 3.5 (Summary of Generic Leading-order Behavior), page 72. Halfway down the page, in the displayed formula following the text "From (3.15) we thus have", the denominator of the summand should have \(\lambda^n\) instead of \(\lambda^{-n}\). [YZ]
Chapter 5
- Section 5.3.1 (Putting the exponent in normal form by a change of variables), page 157. In the first displayed equation there should be a factor of \(\mu_0(t(s))\) in the integrand. [YZ]
- Section 5.5.1 (Partial differential equations for linear dispersive waves), page 167. In Exercise 5.12, "coefficients \(A_\pm(k)\)" should be replaced with "Fourier transforms of \(f\) and \(g\)". [YZ]
- Section 5.7 (Multidimensional Integrals), pages 184-185. A factor of \(2\pi\) has been accidentally omitted from all of the exponents on these two pages. Also, the second displayed equation on page 185 should have a factor of \(2\pi\) in the denominator of the right-hand side. Note also that to obtain the limiting result at the bottom of page 185 a more subtle convergence argument than one based on dominated convergence is probably required. [YZ]
Chapter 6
- Section 6.3.2 (Existence of true solutions described by the formal asymptotic series. The Stokes phenomenon), pages 230-231. The starting values of the double sum indices \(j\) and \(k\) in the expression for \(G_N(z)\) given on page 230 should be zero instead of one. On line 5 of page 231, rather than "the dominant term..." it is better to complete the sentence by saying "the upper bound for \(e^{2\phi_0(z)}G_N(z)\) dominates all other terms on the right-hand side of (6.29)." [YZ]
- Section 6.3.2 (Existence of true solutions described by the formal asymptotic series. The Stokes phenomenon), pages 233-237. Some corrections are in order here related to the hypotheses required for the Contraction Mapping Principle to apply. I suggest the following concrete modifications. On page 233:
- In the statement of Theorem 6.2, replace "bounded" with "closed" on line 2 and replace the parenthetical remark with "(e.g. \(X=B\) or, for some \(g\in B\) and \(M\ge 0\), \(X=\{f\in B\;\text{such that}\;\|f-g\|\le M\}\))".
- In the final paragraph on this page, replace "bounded" with "closed" on line 3 and "open" with "closed" on line 4. On line 4 the given open interval should be written as a closed interval. Finally on line 6 the two inequalities should be written with \(\le\) rather than with \(<\).
- Section 6.3.3 (Another approach to the existence of true solutions and the Stokes phenomenon. Borel summation), page 247. In equation (6.53) and in the subsequent displayed equation, \(n(n+1)\) should be replaced by \(n(n-1)\). [YZ]
- Section 6.3.3 (Another approach to the existence of true solutions and the Stokes phenomenon. Borel summation), page 248. In the last paragraph the convergence condition \(|t|<80/121\) should read instead \(|t|<320/621\).
- Section 6.3.3 (Another approach to the existence of true solutions and the Stokes phenomenon. Borel summation), page 251. The sectors of the complex \(z\)-plane in which the final two displayed asymptotic expansions are valid should be swapped. [YZ]
Chapter 7
- Section 7.1.2 (Solving for \(y_n(x)\). Variation of parameters), page 259. Near the bottom of the page, there are in fact three wavelengths: the two given as well as \(2\pi/k\). [YZ]
- Section 7.2.2 (The special case of an asymptotic power series for \(f(x;\lambda)\)), page 274. Exercise 7.7 is not correctly formulated and should be omitted. Reference to this exercise in the footnotes at the bottom of page 280 should also be omitted. [YZ]
Chapter 10
- Section 10.1.1 (Modulated wavetrains with dispersion and nonlinear effects. The cubic nonlinear Schrödinger equation), Exercise 10.2, page 406. In part (b), the resonant wavenumbers should be \(k=0\) and \(k=\pm 1/\sqrt{10}\). [JB]
- Section 10.2.2 (Derivation of the cubic nonlinear Schrödinger equation), page 432. The expression for the coefficient of the nonlinear term in equation (10.60) is incorrect as written; the equation following (10.60) should instead read \[\beta:=-\frac{1}{4m\omega[V''(0)]^2}\left(m^2\omega^4V^{(IV)}(0)+4V''(0)[V'''(0)]^2\sin^2(\delta)\right).\] The text below is then correspondingly corrected to read "Thus, we see that whether we are in the stable or unstable case depends only on the sign of \(V^{(IV)}(0)\) and the size of \(m^2\omega^4V^{(IV)}(0)\) relative to \(4V''(0)[V'''(0)]^2\sin^2(\delta)\)." [N]
- Section 10.3.2 (Derivation of the Korteweg-de Vries equation), pages 446-447. A term has been omitted from equation (10.89). Equation (10.89) should instead read as \[\frac{\partial N}{\partial T}+G+\frac{\epsilon}{2}\left[\left(\frac{\partial N}{\partial X}\right)^2-\frac{\partial^3N}{\partial X^2\partial T}\right]=O(\epsilon^2)\] Making this correction, one finds that the final term on the left-hand side of each of equations (10.90) and (10.91) should be doubled. Thus, the final two equations in this section should read, respectively \[2\frac{\partial^2N}{\partial\xi\partial\tau}+\frac{1}{3}\frac{\partial^4N}{\partial\xi^4}+3\frac{\partial N}{\partial\xi}\frac{\partial^2N}{\partial\xi^2}=O(\epsilon^2)\] and \[\frac{\partial F}{\partial\tau}+\frac{3}{2}F\frac{\partial F}{\partial\xi}+\frac{1}{6}\frac{\partial^3 F}{\partial\xi^3}=0.\] Of course the factor of \(3/2\) could easily be absorbed by simply rescaling \(F\).
Thanks
- [JB] Thanks to Jordan Bell (University of Toronto).
- [JW] Thanks to Jun-Chieh Wang (University of Michigan).
- [SB] Thanks to Sergey Belov (Rice University).
- [N] Thanks to Nathan (Bath University, UK).
- [YZ] Thanks to Yuchong Zhang (University of Michigan).