向量值H^P空间上的Cesàro算子

设X为一复Banach空间,f:D→X为一个X-值解析函数,f(z)=sum from n≥0(a_nz^n),a_n∈X,设C(f)(z)=sum from n≥0((a_0+a_1+…+a_n)/(n+1)z^n)A(f)(z)=sum from n≥0(sum from k=n to ∞(a_k/(k+1))z^n本文证明了对于任意的1≤p<∞以及复Banach空间X,C为从H^p(X)到H^p(X)的有界线性算子;对于任意的1<p≤∞以及复Banach空间X,A为从(?)(X)到(?)(X)的有界线性算子.这些结果推广了A.G.Siskakis的结果.