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Absolutes of almost realcompactifications

Published online by Cambridge University Press:  09 April 2009

Mohan L. Tikoo
Affiliation:
Department of Mathematics, Southeast Missouri State University, Cape Girardeau, Missouri 63701, U.S.A.
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Abstract

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Given Hausdorff spaces X and Y and a perfect irreducible and θ-continuous map f from X onto Y, technique that carries open (ultra) filters on X to open (ultra) filters on Y back and forth in a natural way is introduced. It is proved that if f is a perfect irreducible and θ-continuous map from X onto Y, then X is almost realcompact if and only if Y is almost realcompact. Several commutativity relations between the ‘absolutes of almost realcompactifications’ and the ‘almost realcompactifications of absólutes’ of a space X are discussed.

Type
Research Article
Copyright
Copyright © Australian Mathematical Society 1986

References

[1]Banaschewski, B., ‘Extensions of topological spaces’, Canad. Math. Bull. 7 (1964), 122.CrossRefGoogle Scholar
[2]Banaschewski, B., ‘Projective covers in categories of topological spaces and topological algebras’, Proceedings of the Kanpur Topological Conference, pp. 6391 (Czechoslovak Academy of Sciences, Academia, Prague 1971).Google Scholar
[3]Dickman, R. F. Jr, Porter, J. R. and Rubin, L. R., ‘Completely regular absolutes and projective objects’, Pacific J. Math. 94 (1981), 277295.CrossRefGoogle Scholar
[4]Fomin, S., ‘Extensions of topological spaces’, Ann. of Math. 44 (1943), 471480.CrossRefGoogle Scholar
[5]Frolík, Z., ‘On almost realcompact spaces’, Bull. Acad. Polon. Sci. Sér. Sci. Math. Phys. Astronom. 49 (1961), 247250.Google Scholar
[6]Frolík, Z., ‘A generalization of realcompact spaces’, Czech. Math. J. 13 (1963), 127138.CrossRefGoogle Scholar
[7]Frolík, Z. and Liu, C. T., ‘An embedding characterization of almost realcompact spaces’, Proc. Amer. Math. Soc. 32 (1972), 294298.CrossRefGoogle Scholar
[8]Iliadis, S. and Fomin, S., ‘The method of centered systems in the theory of topological spaces’, Uspehi Mat. Nauk 21 (1966), 4776. (English translation: Russian Math. Surveys 21 (1966), 37–62.)Google Scholar
[9]Katěov, M., ‘Über H-abgeschlossene und bikompacte Räume’, Časopis Pěst. Math. Fys. 69 (1940), 3649.Google Scholar
[10]Katěov, M., ‘On the equivalence of certain types of extensions of topological spaces’, Časopis Pěst. Mat. Fys. 72 (1947), 101106.CrossRefGoogle Scholar
[11]Liu, C. T., ‘The α-closure αX of a topological space X’, Proc. Amer. Math. Soc. 23 (1969), 605607.Google Scholar
[12]Liu, C. T. and Strecker, G. E., ‘Concerning almost realcompactifications’, Czech. Math. J. 22 (1977), 181190.CrossRefGoogle Scholar
[13]Mioduschewski, J. and Rudolf, L., ‘H-closed and externally disconnected Hausdorff spaces’, Dissertationes Math. 66 (1969), 155.Google Scholar
[14]Ponomarev, V. I., ‘On spaces co-absolute with metric spaces’, Russian Math. Surveys 21 (1966), 87114.CrossRefGoogle Scholar
[15]Porter, J. and Votaw, C., ‘H-closed extensions I’, General Topology and Appl. 3 (1973), 211224.CrossRefGoogle Scholar
[16]Porter, J. and Votaw, C., ‘H-closed extensions II’, Trans. Amer. Math. Soc. 202 (1975), 193209.Google Scholar
[17]Porter, J., Votaw, V., and Woods, R. G., ‘H-closed extensions of absolutes’ to appear.Google Scholar
[18]Jack, R. Porter and Woods, R. Grant, ‘Minimal extremally disconnected Hausdorff spaces’, General Topology and Appl. 8 (1978), 926.Google Scholar
[19]Jack, R. Porter and Woods, R. Grant, ‘Extensions of Hausdorff spaces’, Pacific J. Math. 103 (1982), 111134.Google Scholar
[20]Strauss, D. P., ‘Extremally disconnected spaces’, Proc. Amer. Math. Soc. 18 (1976), 305309.CrossRefGoogle Scholar
[21]Willard, S., General Topology (Addison Wesley, Reading and London, 1968).Google Scholar
[22]Woods, R. Grant, ‘A Tychonoff almost real compactification’, Proc. Amer. Math. Soc. 43 (1974), 200208.CrossRefGoogle Scholar
[23]Woods, R. Grant, ‘A survey of absolutes of topological spaces’, Topological Structures II, pp. 323362 (Math. Centre Tracts 116, Amsterdam, 1979).Google Scholar