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)).
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Materialtyp: | Journal article |
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Springer Verlag
2020
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_version_ | 1826286886392430592 |
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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)). |
first_indexed | 2024-03-07T01:50:23Z |
format | Journal article |
id | oxford-uuid:99e1bf6c-9b38-478d-aefb-2cef4d0d55c9 |
institution | University of Oxford |
last_indexed | 2024-03-07T01:50:23Z |
publishDate | 2020 |
publisher | Springer Verlag |
record_format | dspace |
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 |