English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

The question of existence of outer automorphisms of a simple algebraic group$G$ arises naturally both when working with the Galois cohomology of $G$ and asan example of the algebro-geometric problem of determining which connectedcomponents of the automorphism group of $G$ have rational points. The existencequestion remains open only for four types of groups, and we settle one of theremaining cases, type $^3D_4$. The key to the proof is a Skolem-Noether theoremfor cubic etale subalgebras of Albert algebras which is of independentinterest. Necessary and sufficient conditions for a simply connected group ofouter type $A$ to admit outer automorphisms of order 2 are also given.

Outer automorphisms of algebraic groups and a Skolem-Noether theorem for Albert algebras