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arXiv 0902.0454math.FA
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经典Banach空间中线性算子的范数优化问题

Norm optimization problem for linear operators in classical Banach spaces

Daniel Pellegrino, Eduardo V. Teixeira

摘要:

本文的主要结果表明,对于1 <p和1 <= q,从l_p到l_q的线性算子T达到其范数当且仅当T存在非弱零极大序列(当p = 1时,反例很容易构造).对于1 <p(且q不同于p),作为前面结果的一个推论,我们证明了对于从l_p到l_q的范数达到算子T,任何非弱零极大序列都有一个范数收敛的子序列(这个结果在p = q时是不成立的).我们还研究了线性集的范数实现和非范数实现运营商。

英文摘要:

The main result of the paper shows that, for 1<p and 1<=q, a linear operator T from l_p to l_q attains its norm if, and only if, there exists a not weakly null maximizing sequence for T (counterexamples can be easily constructed when p=1). For 1<p (and q different from p), as a consequence of the previous result we show that any not weakly null maximizing sequence for a norm attaining operator T from l_p to l_q has a norm-convergent subsequence (and this result is sharp in the sense that it is not valid if p=q). We also investigate lineability of the sets of norm-attaining and non-norm attaining operators.

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。

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