arXivDaily arXiv每日学术速递 周一至周五更新
arXiv math/0601509math.FAmath.OA
收藏

Fourier代数中的算子Segal代数

Operator Segal Algebras in Fourier Algebras

Brian E. Forrest, Nico Spronk, Peter J. Wood

摘要:

设G是一个局部紧群,A(G)是它的Fourier代数,L1(G)是G上的Haar可积函数空间.研究了A(G)中的Segal代数SA(G)=A(G)\cap L1(G).它有一个算子空间结构,使它成为完全压缩的巴拿赫代数.计算了SA(G)的对偶空间.我们用它来证明限制算子u|->u| H:SA(G)->A(H),对某些非开闭子群H,是满射完全量映射.证明了若N是非紧闭子群,则平均算子tau_N:SA(G)->L1(G/N),tau_N u(sN)= \int_N u(sn)dn是满射完全商映射.这将算子空间的观点放在SA(G)是“局部A(G)而全局L1”的哲学上。利用算子空间的结构,我们还证明了当G是紧的时,SA(G)是算子顺从的,并且SA(G)总是算子弱顺从的.为了得到后一个事实,我们使用E。超Tauberian巴拿赫代数的Samei理论。

英文摘要:

Let G be a locally compact group, A(G) its Fourier algebra and L1(G) the space of Haar integrable functions on G. We study the Segal algebra SA(G)=A(G)\cap L1(G) in A(G). It admits an operator space structure which makes it a completely contractive Banach algebra. We compute the dual space of SA(G). We use it show that restriction operator u|->u|H:SA(G)->A(H), for some non-open closed subgroups H, is a surjective complete qutient map. We also show that if N is a non-compact closed subgroup, then the averaging operator tau_N:SA(G)->L1(G/N), tau_N u(sN)=\int_N u(sn)dn is a surjective complete quotient map. This puts an operator space perspective on the philosophy that SA(G) is ``locally A(G) while globally L1''. Also, using the operator space structure we can show that SA(G) is operator amenable exactly when when G is compact; and we can show that it is always operator weakly amenable. To obtain the latter fact, we use E. Samei's theory of hyper-Tauberian Banach algebras.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑