---
title: "Ditkin set"
chunk: 1/1
source: "https://en.wikipedia.org/wiki/Ditkin_set"
category: "reference"
tags: "science, encyclopedia"
date_saved: "2026-05-05T12:04:47.032885+00:00"
instance: "kb-cron"
---

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.


== References ==
Ditkin, V. (1939), "On the structure of ideals in certain normed rings", Uchenye Zapiski Moskov. Gos. Univ. Matematika, 30: 83–130, MR 0002012