Abstract
A DC-space (or space of dense constancies) is a Tychonoff space X such that for each f ∈ C(X) there is a family of open sets {U i : i ∈ I}, the union of which is dense in X, such that f, restricted to each U i , is constant. A number of characterizations of DC-spaces are given, which lead to an algebraic generalization of the concept, which, in turn, permits analysis of DC-spaces in the language of archimedean f-algebras. One is led naturally to the notion of an almost DC-space (in which the densely constant functions are dense), and it is shown that all metrizable spaces have this property.
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References
F.W. Anderson: Lattice-ordered rings of quotients. Canad. J. Math. 17 (1965), 434–448.
M. Anderson and T. Feil: Lattice-ordered groups. An introduction. Reidel Texts in the Math. Sciences. Kluwer, Dordrecht, 1988.
B. Banaschewski: Maximal rings of quotients of semi-simple commutative rings. Arch. Math. 16 (1965), 414–420.
A. Bella, A.W. Hager, J. Martinez, S. Woodward and H. Zhou: Specker spaces and their absolutes, I. Topology Appl. 72 (1996), 259–271.
A. Bigard, K. Keimel, S. Wolfenstein: Groupes etA nneaux Réticulés. LNM, Vol. 608. Springer-Verlag, Berlin-Heidelberg-New York, 1977.
R. Bleier: The orthocompletion of a lattice-ordered group. Indag. Math. 38 (1976), 1–7.
L. Gillman, M. Jerison: Rings of Continuous Functions. GTM Vol. 43. Springer-Verlag, Berlin-Heidelberg-New York, 1976.
A. Hager: Minimal covers of topological spaces. Ann. New York Acad. Sci.; Papers on general topology and related category theory and topological algebra Alg. Vol. 552 (1989), 44–59.
J. Lambek: Lectures on Rings and Modules. Blaisdell Publ. Co., Waltham, 1966.
J. Martinez: The maximal ring of quotients of an f-ring. Algebra Universalis 33 (1995), 355–369.
J. Martinez and S. Woodward: Specker spaces and their absolutes, II. Algebra Universalis 35 (1996), 333–341.
J. Porter, R.G. Woods: Extensions and Absolutes of Hausdorff Spaces. Springer-Verlag, Berlin-Heidelberg-New York, 1988.
Y. Utumi: On quotient rings. Osaka Math. J. 8 (1956), 1–18.
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Bella, A., Martinez, J. & Woodward, S.D. Algebras and Spaces of Dense Constancies. Czechoslovak Mathematical Journal 51, 449–461 (2001). https://doi.org/10.1023/A:1013767502518
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DOI: https://doi.org/10.1023/A:1013767502518