Bounds in Cohen’s idempotent theorem

Suppose that G is a finite Abelian group and write W(G) for the set of cosets of subgroups of G. We show that if f:G→Z satisfies the estimate ∥f∥A(G)≤M with respect to the Fourier algebra norm, then there is some z:W(G)→Z such that f=∑W∈W(G)z(W)1W and ∥z∥ℓ1(W(G))=exp(M4+o(1)).

Bibliografiska uppgifter
Huvudupphovsman: Sanders, T
Materialtyp: Journal article
Publicerad: Springer Verlag 2020
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author Sanders, T
author_facet Sanders, T
author_sort Sanders, T
collection OXFORD
description Suppose that G is a finite Abelian group and write W(G) for the set of cosets of subgroups of G. We show that if f:G→Z satisfies the estimate ∥f∥A(G)≤M with respect to the Fourier algebra norm, then there is some z:W(G)→Z such that f=∑W∈W(G)z(W)1W and ∥z∥ℓ1(W(G))=exp(M4+o(1)).
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spelling oxford-uuid:99e1bf6c-9b38-478d-aefb-2cef4d0d55c92022-03-27T00:17:30ZBounds in Cohen’s idempotent theoremJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:99e1bf6c-9b38-478d-aefb-2cef4d0d55c9Symplectic ElementsSpringer Verlag2020Sanders, TSuppose that G is a finite Abelian group and write W(G) for the set of cosets of subgroups of G. We show that if f:G→Z satisfies the estimate ∥f∥A(G)≤M with respect to the Fourier algebra norm, then there is some z:W(G)→Z such that f=∑W∈W(G)z(W)1W and ∥z∥ℓ1(W(G))=exp(M4+o(1)).
spellingShingle Sanders, T
Bounds in Cohen’s idempotent theorem
title Bounds in Cohen’s idempotent theorem
title_full Bounds in Cohen’s idempotent theorem
title_fullStr Bounds in Cohen’s idempotent theorem
title_full_unstemmed Bounds in Cohen’s idempotent theorem
title_short Bounds in Cohen’s idempotent theorem
title_sort bounds in cohen s idempotent theorem
work_keys_str_mv AT sanderst boundsincohensidempotenttheorem