A Generalization of the Method of Steepest Descent,

Abstract

The authors consider the asymptotic expansion as lambda approaches infinity of contour integrals with integrand H(lambda w(z)) g(z), H(t) being an entire function of t. When H is the exponential function, the asymptotic expansion of such an integral can be obtained by the method of steepest descent. The generalization of that method has two major new features. Firstly, the zeros of w(z) are critical points of the integrand. Secondly, there exist points from which no path of descent can be drawn; i.e., there exist curves which are boundaries between two hills of H(lambda w(z)). These features lead to new types of expansions for which the Mellin transform technique of Handelsman and Lew is ideally suited. The authors develop the general method and treat specific examples in detail. (Author)

Document Details

Document Type
Technical Report
Publication Date
Sep 01, 1971
Accession Number
AD0732324

Entities

People

  • Norman Bleistein
  • Richard A. Handelsman

Organizations

  • Denver Research Institute

Tags

DTIC Thesaurus Topics

  • Asymptotic Series
  • Boundaries
  • Contour Integrals
  • Convolution Integrals
  • Cooperation
  • Exponential Functions
  • Functions (Mathematics)
  • Illinois
  • Integrals
  • Inverse Problems
  • Mathematical Analysis
  • Mathematics

Readers

  • Analytical Mechanics
  • Calculus or Mathematical Analysis