ON THE S_{\lambda}(X) AND {\lambda}-ZERO DIMENSIONAL SPACES

Document Type : Research Note

Authors

1 Department of Science, Petroleum University of Technology, P.O. Box 6318714317, Ahvaz, Iran.

2 Department of Science, Ahvaz Islamic Azad University, P.O. Box 6134937333, Ahvaz, Iran.

Abstract

Let $S_\lambda(X)=\{f\in C(X) : |X\setminus Z(f)|<\lambda\}$, such that $\lambda$ is a regular cardinal
number with $\lambda\leq |X|$.
It is generalization of $C_F (X)=S_{\aleph_0}(X)$ and
$SC_F(X)=S_{\aleph_1}(X)$. Using
this concept we extend some of the basic results concerning the socle
to $S_\lambda(X)$. It is shown that
if $X$ is a $\lambda$-pseudo discrete space, then $C_{K,\lambda}(X)\subseteq S_{\lambda}(X)$.
$S_{\lambda}$-completely regular spaces are investigated.
Consequently, $X$ is a $S_{\aleph_1}$-completely regular space if and only if $X$ is $\aleph_1$-zero dimensional space.
$S_{\lambda}P$-spaces are introduced and studied.

Keywords


1. F. Azarpanah, Algebraic properties of some compact spaces, Real Anal. Exchange, 21 (1999), 105–112 .
2. F. Azarpanah, Intersection of essential ideals in C(X), Proc. Amer. Math. Soc., 125(7) (1997), 2149–2154 .
3. F. Azarpanah and O. A. S. Karamzadeh, Algebraic characterization of some disconnected spaces, Italian. J. Pure Appl. Math. 12 (2002), 155–168.
4. F. Azarpanah, O. A. S. Karamzadeh and S. Rahmati, C(X) VS. C(X) modulo its socle, Coll. Math. 3 (2008), 315–336.
5. F. Azarpanah, O. A. S. Karamzadeh, Z. Keshtkar and A. R. Olfati, On maximal ideals of Cc(X) and the uniformity of its localizations, Rocky Mt. J. Math., 48(2) (2018), 1–9.
6. P. Bhattacharjee, M.L. Knox, W. McGovern, The classical ring of quotient of Cc(X), App. Gen.Topol., 15 (2014), 147–154.
7. L. Byun and S. Watson, Local invertibility in subrings of C(X), Bull. Aust. Math. Soc., 46 (1992), 449–458.
8. L. Byun and S. Watson, Prime and maximal ideals in subrings of C(X), Topology Appl., 40(1) (1991), 45–62.
9. J. M. Dominguez, J. Gomez and M.A. Mulero, Intermediate algebras between
C(X) and C(X) as rings of fractions of C(X), Topology Appl., 77 (1997), 115–130.
10. T. Dube, Contracting the Socle in Rings of Continuous Functions, Rend. Semin. Mat. Univ. Padova, 123 (2010), 37–53.
11. R. Engelking, General Topology, Berlin, Germany, Heldermann Verlag (1989).
12. A. A. Estaji and O. A. S. Karamzadeh, On C(X) modulo its socle, Comm. Algebra, 31 (2003), 1561–1571.
13. M. Ghadermazi, O. A. S. Karamzadeh and M. Namdari, On the functionally countable subalgebra of C(X), Rend. Sem. Mat. Univ. Padova, 129 (2013), 47–69.
14. M. Ghadermazi, O. A. S. Karamzadeh and M. Namdari, C(X) versus its functionally countable subalgebra, Bull. Iran. Math. Soc., 245 (2019), 173–187.
15. S. G. Ghasemzadeh, O. A. S. Karamzadeh and M. Namdari, The super socle of the ring of continuous functions, Math. Slovaca, 67 (2017), 1001–1010.
16. L. Gillman and M. Jerison, Rings of continuous functions, Springer-Verlag, 1976.
17. H. Hewitt, Rings of real-valued continuous functions I, Trans. Amer. Math. Soc., 64 (1948), 54–99.
18. O. A. S. Karamzadeh, M. Namdari and S. Soltanpour, On the locally functionally countable subalgebra of C(X), App. Gen. Topology, 16 (2015), 183–207.
19. O. A. S. Karamzadeh and M. Rostami, On the intrinsic topology and some related ideals of C(X), Proc. Amer. Math. Soc., 93 (1985), 179–184.
20. S. Mehran and M. Namdari, The -super socle of the ring of continuous functions, Categories Gen. Algebraic Struct. Appl., 6 (2017), 37–50.
21. S. Mehran, M. Namdari and S. Soltanpour, On the essentiality and primeness of - super socle of C(X), Appl. Gen. Topol., 19 (2018), 261–268.
22. M. Namdari and M. A. Siavoshi, A generalization of compact spaces, JP J. Geom. Topol., 11(3) (2011), 259–270.
23. L. Redlin and S. Watson, Maximal ideals in subalgebras of C(X), Proc. Amer. Math. Soc., 100 (1987), 763–766.
24. L. Redlin and S. Watson, Structure spaces for rings of continuous functions with applications to realcompactifications, Fundamenta Mathematicae, 152 (1997), 151–163.
25. S. Soltanpour, On the locally socle of C(X) whose local cozeroset is cocountable (cofinite), Hacet. J. Math. Stat., 48(5) (2019), 1430–1436.