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Question

Math 6420 • PDE

Fall 2018 • Question 10

Consider integral \[ I(s)=\int _C \frac {e^{s z^2}}{z^2-1}\,dz, \] \(C\) is the vertical line \(\operatorname {Re} z=3\), from \(z=3-i\infty \) to \(z=3+i\infty \), with large (real) parameter \(s\). Find the three-term asymtotic expansion (approximation with three non-zero terms) of this integral as \(s\to +\infty \).

Raw LaTeX

Consider integral
\[
  I(s)=\int_C \frac{e^{s z^2}}{z^2-1}\,dz,
\]
\(C\) is the vertical line \(\operatorname{Re} z=3\), from \(z=3-i\infty\) to
\(z=3+i\infty\), with large (real) parameter \(s\). Find the three-term asymtotic expansion
(approximation with three non-zero terms) of this integral as \(s\to+\infty\).