• 제목/요약/키워드: summable sequences in Banach spaces

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CHARACTERIZATION OF OPERATORS TAKING P-SUMMABLE SEQUENCES INTO SEQUENCES IN THE RANGE OF A VECTOR MEASURE

  • Song, Hi-Ja
    • East Asian mathematical journal
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    • 제24권2호
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    • pp.201-212
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    • 2008
  • We characterize operators between Banach spaces sending unconditionally weakly p-summable sequences into sequences that lie in the range of a vector measure of bounded variation. Further, we describe operators between Banach spaces taking unconditionally weakly p-summable sequences into sequences that lie in the range of a vector measure.

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SEQUENCES IN THE RANGE OF A VECTOR MEASURE

  • Song, Hi Ja
    • Korean Journal of Mathematics
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    • 제15권1호
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    • pp.13-26
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    • 2007
  • We prove that every strong null sequence in a Banach space X lies inside the range of a vector measure of bounded variation if and only if the condition $\mathcal{N}_1(X,{\ell}_1)={\Pi}_1(X,{\ell}_1)$ holds. We also prove that for $1{\leq}p<{\infty}$ every strong ${\ell}_p$ sequence in a Banach space X lies inside the range of an X-valued measure of bounded variation if and only if the identity operator of the dual Banach space $X^*$ is ($p^{\prime}$,1)-summing, where $p^{\prime}$ is the conjugate exponent of $p$. Finally we prove that a Banach space X has the property that any sequence lying in the range of an X-valued measure actually lies in the range of a vector measure of bounded variation if and only if the condition ${\Pi}_1(X,{\ell}_1)={\Pi}_2(X,{\ell}_1)$ holds.

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ON THE PROXIMAL POINT METHOD FOR AN INFINITE FAMILY OF EQUILIBRIUM PROBLEMS IN BANACH SPACES

  • Khatibzadeh, Hadi;Mohebbi, Vahid
    • 대한수학회보
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    • 제56권3호
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    • pp.757-777
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    • 2019
  • In this paper, we study the convergence analysis of the sequences generated by the proximal point method for an infinite family of pseudo-monotone equilibrium problems in Banach spaces. We first prove the weak convergence of the generated sequence to a common solution of the infinite family of equilibrium problems with summable errors. Then, we show the strong convergence of the generated sequence to a common equilibrium point by some various additional assumptions. We also consider two variants for which we establish the strong convergence without any additional assumption. For both of them, each iteration consists of a proximal step followed by a computationally inexpensive step which ensures the strong convergence of the generated sequence. Also, for this two variants we are able to characterize the strong limit of the sequence: for the first variant it is the solution lying closest to an arbitrarily selected point, and for the second one it is the solution of the problem which lies closest to the initial iterate. Finally, we give a concrete example where the main results can be applied.