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Nice separation axioms

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Abstract

The epi-reflective hull B of an objectB in the category of locales is called anice separation axiom provided it enjoys certain properties which are natural generalizations of properties satisfied by the categories of completely regular locales and zero dimensional locales. Invariably, a family ofStone-like duality theorems ensues, distinguishing (for each large enough regular cardinal κ) the full subcategory of all κ-LindelöfB-objects. Some corollaries for topological spaces arise, as well as some open problems, upon “taking of spatial parts”.

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References

  1. H. Applegate and M. Tierney: ‘Iterated cotriples’,Spring. Lec. Notes Math. 137 (1970) 56–99.

    Google Scholar 

  2. B. Banaschewski and C. J. Mulvey: ‘Stone-Čech compactification of locales I’,Houston J. Math. 6 (1980) 301–312.

    Google Scholar 

  3. M. Barr and C. Wells:Toposes, Triples and Theories. Grundlehren Math. Wiss.278 (Springer-Verlag) (1985) esp. pp. 98–114.

  4. J. Beck: ‘Triples, algebras, and cohomology’, Ph.D Thesis, Columbia University (1967).

  5. H. Cook: ‘Continua which admit only the identity mapping onto non-degenerate subcontinua’,Fund. Math. 60 (1967) 241–249.

    Google Scholar 

  6. H. Herrlich: ‘Fortsetzbarkeit stetiger Abbildungen und Kompaktheitsgrad topologischer Räume’,Math. Zeitschr. 96 (1967) 228–255.

    Google Scholar 

  7. H. Herrlich: ‘On the concept of reflections in general topology’,Contributions to the Extension Theory of Topological Structures, Berlin Symposium. (Academic Press) (1969) 111–113.

  8. H. Herrlich and M. Hušek: ‘Galois connections categorically’,J. Pure Appl. Algebra 66 (1990) 165–180.

    Google Scholar 

  9. M. Hušek: ‘The Class of κ-compact spaces is simple’,Math. Zeitschr. 110 (1969) 123–126.

    Google Scholar 

  10. J. R. Isbell: ‘Atomless parts of spaces’,Math. Scand. 31 (1972) 5–32.

    Google Scholar 

  11. J. R. Isbell: ‘Epimorphisms and dominions’,Proc. Confer. Categorical Algebra (La Jolla, 1965). Springer, Berlin (1966) 232–246.

    Google Scholar 

  12. J. R. Isbell: ‘General functorial semantics’,Amer. J. Math. 94 (1972) 535–596.

    Google Scholar 

  13. P. B. Johnson: ‘κ-Lindelöf Locales and their spatial parts’,Cahiers Top. et Géom. Diff. XXXII-4 (1991) 297–313.

    Google Scholar 

  14. P. B. Johnson: ‘Functors of sub-descent type and dominion theory’ (submitted for publication inProc. AMS). 1992.

  15. P. T. Johnstone:Stone Spaces. Cambridge Studies in Advanced Math.3 (Cambridge University Press) 1982.

  16. F. E. J. Linton: ‘Applied functorial semantics, II’,Spring. Lec. Notes Math. 80 (1969) 53–74.

    Google Scholar 

  17. J. Madden: ‘κ-frames’,J. Pure Appl. Algebra 70 (1991) 107–127.

    Google Scholar 

  18. J. Madden and J. Vermeer: ‘Lindelöf locales and realcompactness’,Math. Proc. Camb. Phil. Soc. 99 (1986) 473–480.

    Google Scholar 

  19. G. Reynolds: ‘On the spectrum of a real representable ring’,Applications of Sheaves. Spring. Lec. Notes Math.753 (1979) 595–611.

    Google Scholar 

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This paper, consisting primarily of excerpts from the author's Ph.D. thesis, Wesleyan University, Middletown, Connecticut (1992), also represents, in part, the results of research engaged in at Charles University, Prague, during the 1992–1993 academic year, with the support of the United States Information Agency and the Fulbright Program.

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Johnson, P.B. Nice separation axioms. Appl Categor Struct 2, 205–218 (1994). https://doi.org/10.1007/BF00873300

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