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

For a finite group $G$, we introduce a generalization of norm relations inthe group algebra $\mathbb Q[G]$. We give necessary and sufficient criteria forthe existence of such relations and apply them to obtain relations between thearithmetic invariants of the subfields of a normal extension of algebraicnumber fields with Galois group $G$. On the algorithmic side this leads tosubfield based algorithms for computing rings of integers, $S$-unit groups andclass groups. For the $S$-unit group computation this yields a polynomial timereduction to the corresponding problem in subfields. We compute class groups oflarge number fields under GRH, and new unconditional values of class numbers ofcyclotomic fields.

Norm relations and computational problems in number fields