A Note on the Pettis Integral and the Bourgain Property

  • Lim, Jong Sul (Department of Mathematics Education Chungbuk National University) ;
  • Eun, Gwang Sik (Department of Mathematics Education Chungbuk National University) ;
  • Yoon, Ju Han (Department of Mathematics Education Chungbuk National University)
  • Received : 1992.05.26
  • Published : 1992.07.31

Abstract

In 1986, R. Huff [3] showed that a Dunford integrable function is Pettis integrable if and only if T : $X^*{\rightarrow}L_1(\mu)$ is weakly compact operator and {$T(K(F,\varepsilon))|F{\subset}X$, F : finite and ${\varepsilon}$ > 0} = {0}. In this paper, we introduce the notion of Bourgain property of real valued functions formulated by J. Bourgain [2]. We show that the class of pettis integrable functions is linear space and if lis bounded function with Bourgain property, then T : $X^{**}{\rightarrow}L_1(\mu)$ by $T(x^{**})=x^{**}f$ is $weak^*$ - to - weak linear operator. Also, if operator T : $L_1(\mu){\rightarrow}X^*$ with Bourgain property, then we show that f is Pettis representable.

Keywords