Home Dominated Convergence and Stone-Weierstrass Theorem
Article
Licensed
Unlicensed Requires Authentication

Dominated Convergence and Stone-Weierstrass Theorem

  • J.-P. Jurzak
Published/Copyright: June 9, 2010

Abstract

Let C(X; ℝ) the algebra of continuous real valued functions defined on a locally compact space X. We consider linear subspaces 𝔸 ⊂ C(X; ℝ) having the following property: there is a sequence (Φj)j∈ℕ of positive functions in 𝔸 with limx→∞ Φj(x) = +∞ for every j ∈ ℕ, such that 𝔸 consists of functions ƒ ∈ C(X; ℝ) bounded above for the absolute value by an homothetic of some Φn (n depends on each ƒ). Dominated convergence of a sequence (gn)n≥1 in 𝔸 is an estimation of the form |gn(x) – g(x)| ≤ εn|h(x)| for all xX and all n ∈ ℕ where gn, g, h ∈ 𝔸 and εn → 0 as n → ∞. We extend the Stone-Weierstrass theorem to subalgebras or lattices 𝔹 ⊂ 𝔸 and we show that the dominated convergence for sequences is exactly the convergence of sequences when 𝔸 is endowed with a locally convex (DF)-space topology.

Received: 2003-04-01
Revised: 2004-09-10
Published Online: 2010-06-09
Published in Print: 2005-December

© Heldermann Verlag

Downloaded on 21.11.2025 from https://www.degruyterbrill.com/document/doi/10.1515/JAA.2005.207/html
Scroll to top button