On e-spaces and rings of real valued e-continuous functions

S. Afrooz

Iran, Islamic Republic of

Khorramshahr University of Marine Science and Technology

Faculty of Marine Engineering

F. Azarpanah

https://orcid.org/0000-0002-0788-2195

Iran, Islamic Republic of

Shahid Chamran University of Ahvaz image/svg+xml

Department of Mathematics

N. Hasan Hajee

Iran, Islamic Republic of

Shahid Chamran University of Ahvaz image/svg+xml

Department of Mathematics

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Accepted: 2023-01-10

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Published: 2023-10-02

DOI: https://doi.org/10.4995/agt.2023.17743
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Keywords:

e-space, e-continuous function, real maximal ideal, quasicomponent, zero-dimensional space

Supporting agencies:

This research was not funded

Abstract:

Whenever the closure of an open set is also open, it is called e-open and if a space have a base consisting of e-open sets, it is called e-space. In this paper we first introduce and study e-spaces and e-continuous functions (we call a function f from a space X to a space Y an e-continuous at x ∈ X if for each open set V containing f(x) there is an e-open set containing x with f ( U ) ⊆ V ). We observe that the quasicomponent of each point in a space X is determined by e-continuous functions on X and it is characterized as the largest set containing the point on which every e-continuous function on X is constant. Next, we study the rings Ce( X ) of all real valued e-continuous functions on a space X. It turns out that Ce( X ) coincides with the ring of real valued clopen continuous functions on X which is a C(Y) for a zero-dimensional space Y whose elements are the quasicomponents of X. Using this fact we characterize the real maximal ideals of Ce( X ) and also give a natural representation of its maximal ideals. Finally we have shown that Ce( X ) determines the topology of X if and only if it is a zero-dimensional space.

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References:

S. Afrooz, F. Azarpanah and M. Etebar, On rings of real valued clopen continuous functions, Appl. Gen. Topol. 19, no. 2 (2018), 203-216. https://doi.org/10.4995/agt.2018.7667

Z. Arjmandnezhad, F. Azarpanah, A. A. Hesari and A. R. Salehi, Characterizations of maximal $z^circ$-ideals of C(X) and real maximal ideals of q(X), Quaest. Math. 45 (2022), 1575-1587. https://doi.org/10.2989/16073606.2021.1966544

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