Ditkin set

In mathematics, a Ditkin set, introduced by (Ditkin 1939), is a closed subset of the circle such that a function f vanishing on the set can be approximated by functions φnf with φ vanishing in a neighborhood of the set.

The brackets have to come after the name "Ditkin" and before the year "1939".

References

This article is issued from Wikipedia - version of the Sunday, September 02, 2012. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.