COMPACT COMPOSITION OPERATORS ON THE BLOCH SPACE

被引:487
作者
MADIGAN, K [1 ]
MATHESON, A [1 ]
机构
[1] LAMAR UNIV,DEPT MATH,BEAUMONT,TX 77710
关键词
COMPOSITION OPERATOR; COMPACT OPERATOR; BLOCH SPACE; CUSP;
D O I
10.2307/2154848
中图分类号
O1 [数学];
学科分类号
0701 ; 070101 ;
摘要
Necessary and sufficient conditions are given for a composition operator C(phi)f = o phi to be compact on the Bloch space B and on the little Bloch space B-0. Weakly compact composition operators on B-0 are shown to be compact. If phi is an element of B-0 is a conformal mapping of the unit disk D into itself whose image phi(D) approaches the unit circle T only in a finite number of nontangential cusps, then C-phi is compact on B-0 On the other hand if there is a point of T boolean AND phi(D) at which phi(D) does not have a cusp, then C-phi is not compact.
引用
收藏
页码:2679 / 2687
页数:9
相关论文
共 9 条
  • [1] Ahlfors L. V., 1973, CONFORMAL INVARIANTS
  • [2] ANDERSON JM, 1974, J REINE ANGEW MATH, V270, P12
  • [3] DIESTEL J, 1984, SEQUENCES SERIES BAN
  • [4] GARNETT J, 1986, U ARKANSAS LECTURE N, V8
  • [5] POMMERENKE C, 1992, BOUNDARY BEHAVIOUR C
  • [6] ROCHBERG R, 1982, MICH MATH J, V29, P229
  • [7] Rochberg R., 1985, OPERATORS FUNCTION T, P225
  • [8] Shapiro J. H., 1993, COMPOSITION OPERATOR
  • [9] SHAPIRO JH, IN PRESS J FUNCT ANA