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Weakly least integer closed groups

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Abstract

An archimedean lattice-ordered groupA with distinguished weak unit has the canonical Yosida representation as an ℓ-group of extended real-valued functions on a certain compact Hausdorff spaceY A. Such an ℓ-groupA is calledleast integer closed, orLIC (resp.,weakly least integer closed, orwLIC) if, in the representation,aA implies [a] ∈A (resp., there isa′A witha′=[a] on a dense set inY A), where [r] ≡ the least integer greater than or equal tor. Earlier, we have studiedLIC groups, with an emphasis on their a-extensions. Here, we turn towLIC groups: we give an intrinsic (though awk-ward) characterization in terms of existence of certain countable suprema. This results also in an intrinsic characterization ofLIC, previously lacking. Also,wLIC is a hull class (whichLIC is not), and the hullwlA is “somewhere near” the projectable hullpA. The best comparison comes from a (somewhat novel) factoringpA=loc(wpA), wherewpA is the “weakly projectable” hull (defined here), andlocB is the “local monoreflection”; then,wpAwlAloc(wpA), andpAloc(wlA), while with a strong unit, all these coincide. Numerous examples and special cases are examined.

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References

  1. M. Anderson, P. F. Conrad,The hulls of C(X), Rocky Mountain J. Math.,12 (1982), 7–22.

    MATH  MathSciNet  Google Scholar 

  2. M. Anderson, T. Feil,Lattice-Ordered Groups, Reidel, Dordrecht, (1989).

    MATH  Google Scholar 

  3. E. Aron, A. W. Hager,Convex vector lattices and ℓ-algebras, Top. Appl.,12 (1981), 1–10.

    Article  MATH  MathSciNet  Google Scholar 

  4. R. N. Ball, A. W. Hager,Epicompletion of archimedean ℓ-groups and vector lattices with weak unit, J. Austral. Math. Soc.,48 (1990), 25–56.

    MATH  MathSciNet  Google Scholar 

  5. R. N. Ball, A. W. Hager,Archimedean-kernel-distinguishing extensions of archimedean lattice-ordered groups with weak unit, Indian J. Math.,29 (1987), 351–368.

    MATH  MathSciNet  Google Scholar 

  6. R. N. Ball, A. W. Hager,Applications of spaces with filters to archimedean ℓ-groups with unit, Ordered Algebraic Structures, edited by J. Martinez, Kluwer, Dordrecht, (1989), 99–112.

    Google Scholar 

  7. R. N. Ball, A. W. Hager, A. J. Macula,An α-disconnected space has no proper monic preimage, Top. Appl.37 (1990), 141–151.

    Article  MATH  MathSciNet  Google Scholar 

  8. R. N. Ball, A. W. Hager, C. Neville,The quasi-F k cover of a compact Hausdorff space and the k-ideal completion of an archimedean ℓ-group, Dekker Notes, 123 (1990), edited by R.M. Shortt. 7–50.

  9. A. Bigard, K. Keimel, S. Wolfenstein,Groupes et Anneaux Réticulés, Lecture Notes in Math., 608, Springer-Verlag, Berlin 1997.

    Google Scholar 

  10. G. Birkhoff,Lattice Theory, (Third Edition), Amer. Math. Soc., Providence 1967.

    MATH  Google Scholar 

  11. P. F. Conrad,The essential closure of an archimedean lattice-ordered group, Duke Math. J.,38 (1971), 151–160.

    Article  MATH  MathSciNet  Google Scholar 

  12. P. F. Conrad,The hulls of representable ℓ-groups and f-rings, J. Austral. Math. Soc.,16 (1972), 385–415.

    MathSciNet  Google Scholar 

  13. M. Darnel,Theory of Lattice-Ordered Groups, Pure and Appl. Math.,187, Marcel Dekker, New York, 1995.

    MATH  Google Scholar 

  14. F. Dashiell, A. W. Hager, M. Henriksen,Order-Cauchy completions of rings and vector lattices of continuous functions, Canad. J. Math.,32 (1980), 657–685.

    MATH  MathSciNet  Google Scholar 

  15. L. Fuchs,Partially Ordered Algebraic Systems, Addison-Wesley, Reading, 1963.

    MATH  Google Scholar 

  16. L. Gillman, M. Jerison,Rings of Continuous Functions, Grad. Texts in Math.,43, Springer-Verlag, Berlin, 1976.

    MATH  Google Scholar 

  17. A. Gleason,Projective topological spaces, Illinois J. Math.,2 (1958), 482–489.

    MATH  MathSciNet  Google Scholar 

  18. A. W. Hager,Minimal covers of topological spaces, Papers on General Topology, etc., Ann. N.Y. Acad. Sciences,552 (1989), 44–59.

    Article  MathSciNet  Google Scholar 

  19. A. W. Hager, C. Kimber,Some examples of hyperarchimedean lattice-ordered groups, Manuscript submitted for publication.

  20. A. W. Hager, C. Kimber, W. McGovern,Least integer closed groups, in Ordered Algebraic Structures (J. Martinez, Ed.), Kluwer, Dordrecht, 2002, 245–260.

    Google Scholar 

  21. A. W. Hager, J. Martinez,α-Projectable and laterally α-complete archimedean lattice-ordered groups, In S. Bernau (ed.), Proc. Conf. on Mem. of T. Retta, Temple U., PA/Addis Ababa, 1995, Ethiopian J. Sci.,19 (1996), 73–84.

    Google Scholar 

  22. A. W. Hager, J. Martinez,Hulls for various kinds of α-completeness in archimedean lattice-ordered groups, Order16 (1999), 89–103.

    Article  MATH  MathSciNet  Google Scholar 

  23. A. W. Hager, L. Robertson,Representing and ringifying a Riesz space, Symp. Math.,21 (1977), 411–431.

    MathSciNet  Google Scholar 

  24. A. W. Hager, L. Robertson,Extremal units in an archimedean Riesz space, Rend. Sem. Mat. Univ. Padova,59 (1978), 97–115.

    MATH  MathSciNet  Google Scholar 

  25. A. W. Hager, L. C. Robertson,On the embedding into a ring of an archimedean ℓ-group, Canad. J. Math.,31 (1979), 1–8.

    MATH  MathSciNet  Google Scholar 

  26. M. Henriksen, D. Johnson,On the structure of a class of archimedean lattice-ordered algebras, Fund. Math.,50 (1961), 73–94.

    MATH  MathSciNet  Google Scholar 

  27. M. Henriksen, J. Vermeer, R. G. Woods,Quasi-F covers of Tychonoff spaces, Trans. Amer. Math. Soc.,303(2) (1987), 779–803.

    Article  MATH  MathSciNet  Google Scholar 

  28. J. R. Isbell,Uniform spaces, Amer. Math. Soc., Providence 1964.

    MATH  Google Scholar 

  29. W. Luxemburg, A. Zaanen,Riesz Spaces I, North Holland, Amsterdam, 1971.

    MATH  Google Scholar 

  30. A. J. Macula,α-Dedekind complete archimedean vector lattices versus α-quasi-F spaces, Top. Appl.,44 (1992), 217–234.

    Article  MATH  MathSciNet  Google Scholar 

  31. J. Martinez,Polar functions I, The summand-inducing hull of an archimedean l-group with unit, in Ordered Algebraic Structures (J. Martinez, Ed.), Kluwer, Dordrecht, 2002, 275–299.

    Google Scholar 

  32. J. Martinez,Hull classes of archimedean lattice-ordered groups with unit, a survey, in Ordered Algebraic Structures (J. Martinez, Ed.), Kluwer, Dordrecht, 2002, 89–121.

    Google Scholar 

  33. J. MartinezPolar classes II: To appear.

  34. J. R. Porter, R. G. Woods,Extensions and Absolutes of Hausdorff Spaces, Springer-Verlag, Berlin, (1988).

    MATH  Google Scholar 

  35. J. Vermeer,The smallest basically disconnected preimage of a space, Top. Appl.,17 (1984), 217–232.

    Article  MathSciNet  Google Scholar 

  36. E. Weinberg,Higher Degrees of Distributivity in Lattices of Continuous Functions, Thesis, Purdue Univ., (1961).

  37. K. Yosida,On the representation of the vector lattice, Proc. Imp. Acad. Tokyo,18 (1942), 339–343.

    Article  MATH  MathSciNet  Google Scholar 

  38. A. C. Zaanen,Riesz Spaces II, North Holland, Amsterdam, (1983).

    MATH  Google Scholar 

  39. V. K. Zakharov, A. V. Koldunov,The sequential absolute and its characterizations, Soviet Math. Dokl.,22 (1980), 70–74.

    MATH  Google Scholar 

  40. V. K. Zakarov, A. V. Koldunov,Characterization of the σ-cover of a compact space, Math. Nachr.,107 (1982), 7–16.

    Article  MathSciNet  Google Scholar 

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Hager, A.W., Kimber, C.M. & McGovern, W.W. Weakly least integer closed groups. Rend. Circ. Mat. Palermo 52, 453–480 (2003). https://doi.org/10.1007/BF02872765

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