Unbounded Vectorial Cauchy Completion of Vector Metric Spaces

Unbounded Vectorial Cauchy Completion of Vector Metric Spaces

A sequence (??) in a Riesz space E is called uo-convergent (or unbounded orderconvergent) to ? ∈ ? if |?? − ?| ∧ ??→0 for all ? ∈ ?+ and unbounded order Cauchy(uo-Cauchy) if |?? − ??+?| is uo-convergent to 0. In the first part of this study wedefine ??,?-convergence (or unbounded vectorial convergence) in vector metric spaces,which is more general than usual metric spaces, and examine relations betweenunbounded order convergence, unbounded vectorial convergence, vectorial convergenceand order convergence. In the last part we construct the unbounded Cauchy completionof vector metric spaces by the motivation of the fact that every metric space has Cauchycompletion. In this way, we have obtained a more general completion of vector metricspaces.

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  • Nakano, H., “Ergodic theorems in semi-ordered linear spaces”, Ann. Math., 49: 538-556, (1948).
  • DeMarr, R., “Partially ordered linear spaces and locally convex linear topological spaces”, Illinois J. Math., 8: 601-606, (1964).
  • Kaplan, S., “On unbounded order convergence, Real Anal. Exchange”, 23(1): 175-184, (1998-99).
  • Gao, N. and Xanthos, F., “Unbounded order convergence and application to martingales without probability”, J. Math. Anal. Appl., 415(2): 931-947, (2014).
  • Gao, N., Troitsky, V.G. and Xanthos, F., “Uo-convergence and its applications to cesáro means in Banach lattices”, Israel Journal of Math., 220: 649-689, (2017).
  • Aliprantis, C.D. and Burkinshaw, O., Positive Operators, Springer, Dordrecht, (2006).
  • Luxemburg, W.A.J. and Zaanen, A.C., Riesz Space I, North-Holland, Amsterdam, The Netherland, (1971).
  • Çevik, C. and Altun, I., “Vector metric spaces and some properties”, Topol. Methods Nonlinear Anal., 34(2): 375-382, (2009).
  • Çevik, C., Altun, I., Şahin, H. and Özeken, Ç.C., “Some fixed point theorems for contractive mapping in ordered vector metric spaces”, J. Nonlinear Sci. Appl., 10 (4): 1424-1432, (2017).