• Title/Summary/Keyword: sequence spaces

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ON COTYPE AND SUMMING PROPERTIES FOR BANACH SPACE OPERATORS

  • Song, Hi Ja
    • Korean Journal of Mathematics
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    • v.13 no.2
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    • pp.255-273
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    • 2005
  • We characterize Gaussian cotype X operators acting between Banach spaces, where X is a Banach sequence space. Further we give an extensive presentation of results on the connections between cotype and summing operators.

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ALGEBRAIC SPECTRAL SUBSPACES OF OPERATORS WITH FINITE ASCENT

  • Han, Hyuk
    • Journal of the Chungcheong Mathematical Society
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    • v.29 no.4
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    • pp.677-686
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    • 2016
  • Algebraic spectral subspaces were introduced by Johnson and Sinclair via a transnite sequence of spaces. Laursen simplified the definition of algebraic spectral subspace. Algebraic spectral subspaces are useful in automatic continuity theory of intertwining linear operators on Banach spaces. In this paper, we characterize algebraic spectral subspaces of operators with finite ascent. From this characterization we show that if T is a generalized scalar operator, then T has finite ascent.

WEAK AND STRONG CONVERGENCE THEOREMS FOR A SYSTEM OF MIXED EQUILIBRIUM PROBLEMS AND A NONEXPANSIVE MAPPING IN HILBERT SPACES

  • Plubtieng, Somyot;Sombut, Kamonrat
    • Bulletin of the Korean Mathematical Society
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    • v.50 no.2
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    • pp.375-388
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    • 2013
  • In this paper, we introduce an iterative sequence for finding solution of a system of mixed equilibrium problems and the set of fixed points of a nonexpansive mapping in Hilbert spaces. Then, the weak and strong convergence theorems are proved under some parameters controlling conditions. Moreover, we apply our result to fixed point problems, system of equilibrium problems, general system of variational inequalities, mixed equilibrium problem, equilibrium problem and variational inequality.

ON APPROXIMATION PROPERTIES OF BALAZS-SZABADOS OPERATORS AND THEIR KANTOROVICH EXTENSION

  • Agratini, Octavian
    • Journal of applied mathematics & informatics
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    • v.9 no.2
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    • pp.531-542
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    • 2002
  • In this paper we deal with a sequence of positive linear operators ${{R_n}}^{[$\beta$]}$ approximating functions on the unbounded interval [0, $\infty$] which were firstly used by K. balazs and J. Szabados. We give pointwise estimates in the framework of polynomial weighted function spaces. Also we establish a Voronovskaja type theorem in the same weighted spaces for ${{K_n}}^{[$\beta$]}$ operators, representing the integral generalization in Kantorovich sense of the ${{R_n}}^{[$\beta$]}$.

COMPACT MATRIX OPERATORS BETWEEN THE SPACES m(ϕ), n(ϕ) AND ℓp

  • Malkowsky, Eberhard;Mursaleen, Mohammad
    • Bulletin of the Korean Mathematical Society
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    • v.48 no.5
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    • pp.1093-1103
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    • 2011
  • We give the characterizations of the classes of matrix trans-formations ($m(\phi),{\ell}_p$), ($n(\phi),{\ell}_p$) ([5, Theorem 2]), (${\ell}_p,m(\phi)$) ([5, Theorem 1]) and (${\ell}_p,n(\phi)$) for $1{\leq}p{\leq}{\infty}$, establish estimates for the norms of the bounded linear operators defined by those matrix transformations and characterize the corresponding subclasses of compact matrix operators.

THE CONVERGENCE THEOREMS FOR COMMON FIXED POINTS OF UNIFORMLY L-LIPSCHITZIAN ASYMPTOTICALLY Φ-PSEUDOCONTRACTIVE MAPPINGS

  • Xue, Zhiqun
    • Bulletin of the Korean Mathematical Society
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    • v.47 no.2
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    • pp.295-305
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    • 2010
  • In this paper, we show that the modified Mann iteration with errors converges strongly to fixed point for uniformly L-Lipschitzian asymptotically $\Phi$-pseudocontractive mappings in real Banach spaces. Meanwhile, it is proved that the convergence of Mann and Ishikawa iterations is equivalent for uniformly L-Lipschitzian asymptotically $\Phi$-pseudocontractive mappings in real Banach spaces. Finally, we obtain the convergence theorems of Ishikawa iterative sequence and the modified Ishikawa iterative process with errors.

A Note on a Result of Yu. V. Prokhorov in General Banach Spaces

  • Dug Hun Hong
    • Communications for Statistical Applications and Methods
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    • v.4 no.1
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    • pp.255-258
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    • 1997
  • We prove a conjecture of Yu. V. Prokhorov in general Banach Spaces ; let ($X_n$, n$\geq$1} be a sequence of independent identically and symmetrically distributed Banach valued random variables, then the relation $\mid$$\mid$$S_n$$\mid$$\mid$/$b_n$ -> 1 a.s. cannot hold for any choice of constants $b_n$.

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FIXED POINT THEORY FOR PERMISSIBLE MAPS VIA INDEX THEORY

  • Balaj, Mircea;Cho, Yeol-Je;O'Regan, Donal
    • East Asian mathematical journal
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    • v.24 no.1
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    • pp.97-103
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    • 2008
  • New fixed point theorems for permissible maps between $Fr{\acute{e}}chet$ spaces are presented. The proof relies on index theory developed by Dzedzej and on viewing a $Fr{\acute{e}}chet$ space as the projective limit of a sequence of Banach spaces.

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