Gleason–Kahane–Żelazko theorem

theorem that a nonzero linear functional on a unital complex Banach algebra is multiplicative iff it maps each element of the Banach algebra to an element of its spectrum
Intangible theorem Q2226660
Press Enter · cited answer in seconds

Gleason–Kahane–Żelazko theorem

Summary

Gleason–Kahane–Żelazko theorem is a theorem[1].

Key Facts

  • Gleason–Kahane–Żelazko theorem's instance of is recorded as theorem[2].
  • Andrew Gleason is named after Gleason–Kahane–Żelazko theorem[3].
  • Jean-Pierre Kahane is named after Gleason–Kahane–Żelazko theorem[4].
  • Wiesław Żelazko is named after Gleason–Kahane–Żelazko theorem[5].
  • Gleason–Kahane–Żelazko theorem's defining formula is recorded as (\phi\ne0\land\forall a,b\in A\colon \phi(ab)=\phi(a)\phi(b))\iff(\forall a\in A\colon\phi(a)\in\sigma(a))[6].
  • Gleason–Kahane–Żelazko theorem's studied by is recorded as functional analysis[7].
  • Gleason–Kahane–Żelazko theorem's Google Knowledge Graph ID is recorded as /g/120scz93[8].
  • Gleason–Kahane–Żelazko theorem's maintained by WikiProject is recorded as WikiProject Mathematics[9].

📑 Cite this page

Use these citations when quoting this entity in research, articles, AI prompts, or wherever provenance matters. We aggregate Wikidata + Wikipedia + authoritative open-data sources; the stitched, scored, cross-referenced view is what 4ort.xyz contributes.

APA 4ort.xyz Knowledge Graph. (2026). Gleason–Kahane–Żelazko theorem. Retrieved May 3, 2026, from https://4ort.xyz/entity/gleason-kahane-elazko-theorem
MLA “Gleason–Kahane–Żelazko theorem.” 4ort.xyz Knowledge Graph, 4ort.xyz, 3 May. 2026, https://4ort.xyz/entity/gleason-kahane-elazko-theorem.
BibTeX @misc{4ortxyz_gleason-kahane-elazko-theorem_2026, author = {{4ort.xyz Knowledge Graph}}, title = {{Gleason–Kahane–Żelazko theorem}}, year = {2026}, url = {https://4ort.xyz/entity/gleason-kahane-elazko-theorem}, note = {Accessed: 2026-05-03}}
LLM prompt According to 4ort.xyz Knowledge Graph (aggregator of Wikidata, Wikipedia, and authoritative open-data sources): Gleason–Kahane–Żelazko theorem — https://4ort.xyz/entity/gleason-kahane-elazko-theorem (retrieved 2026-05-03)

Canonical URL: https://4ort.xyz/entity/gleason-kahane-elazko-theorem · Last refreshed: