Is computing with the finite Fourier transform pure or applied mathematics?

Computing with the Finite Fourier Transform Is Mathematics!

In November of 1979, there appeared a paper in the Bulletin of the AMS by L. Auslander and R. Tolimieri with the delightful title of “Is Computing with the Finite Fourier Transform Pure or Applied Mathematics?” The question was of course rhetorical and one of the main goals of the paper was to show that the finite Fourier transform, and the family of efficient algorithms used to compute it, the...

Computing with the Finite Fourier Transform Is

How Applied Mathematics Became Pure

This paper traces the evolution of thinking on how mathematics relates to the world— from the ancients, through the beginnings of mathematized science in Galileo and Newton, to the rise of pure mathematics in the nineteenth century. The goal is to better understand the role of mathematics in contemporary science. My goal here is to explore the relationship between pure and applied mathematics a...

Compatible with the Finite Fourier Transform

Let Z/n denote the integers mod n and let % denote the finite Fourier transform on L\Z/n). We let ©2$), » F operate on ©2L2(Z/n) and show that ©2L2(Z/n) can be given a graded algebra structure (with no zero divisors) such that f(/g) ■" ^U)^(g). We do this by establishing a natural isomorphism with the algebra of theta functions with period i. In addition, we find all algebra structures on 02L2(...

Finite Fourier Transform, Circulant Matrices, and the Fast Fourier Transform

Suppose we have a function s(t) that measures the sound level at time t of an analog audio signal. We assume that s(t) is piecewise-continuous and of finite duration: s(t) = 0 when t is outside some interval a ≤ t ≤ b. Make a change of variable x = (t− a)/(b− a) and set f(x) = s(t). Then 0 ≤ x ≤ 1 when a ≤ t ≤ b, and f(x) is a piecewise continuous function of x. We convert f(x) into a digital s...