摘要
ItisshowninthispaperthatahyponormalweightedshiftofnormoneisunitarilyequivalenttoaToeplitzoperatorifandonlyifitsweights{an}0∞satisfy1-丨an丨2=(1-丨a0丨2)n+1n≥0.Inparticular,thisanswerstheAbrahamse’sProblem2.Asaconse-quence,the(surprising)answer,obtainedfirstbyC.C.Coweninanexplicitform,toHalmos’Question5isrecaptured.
出版日期
1985年03月13日(中国期刊网平台首次上网日期,不代表论文的发表时间)