O'Farrell, Anthony G. (1990) A series of surprises. Irish Mathematics Teachers' Association Newsletter (73). pp. 28-33.

Download (75kB)

Abstract

Riemann’s theorem on conditionally–convergent series surprises a lot of people. Some people react to it by retreating to the view that only absolute convergence deserves to be taken seriously. I go the other way. What I take from it is that the ordinary notion of the convergence of a series is not so sacred, after all. That notion relates to one particular way of adding up a series, one of many. Depending on the circumstances, one of the other ways may be more appropriate or interesting. The idea that a series should add up in the usual way is just a prejudice. For instance, with the Fourier series of a continuous function, it is a fact that the series often fails to converge in the ordinary way, but we know that the Cesaro means always converge uniformly to the function.

Item Type:	Article
Keywords:	Riemann’s theorem on conditionally–convergent series; Euler.
Academic Unit:	Faculty of Science and Engineering > Mathematics and Statistics
Item ID:	1799
Depositing User:	Prof. Anthony O'Farrell
Date Deposited:	20 Jan 2010 16:38
Journal or Publication Title:	Irish Mathematics Teachers' Association Newsletter
Publisher:	Irish Mathematics Teachers' Association (IMTA)
Refereed:	No
URI:
Use Licence:	This item is available under a Creative Commons Attribution Non Commercial Share Alike Licence (CC BY-NC-SA). Details of this licence are available here

Repository Staff Only(login required)

Item control page

Downloads

Origin of downloads