Directed complete poset models of T1 spaces

2016 ◽  
Vol 164 (1) ◽  
pp. 125-134 ◽  
Author(s):  
DONGSHENG ZHAO ◽  
XIAOYONG XI
Keyword(s):  
Topological Space ◽  
Positive Answer ◽  
Scott Topology ◽  
Maximal Points

AbstractA poset model of a topological space X is a poset P such that the subspace Max(P) of the Scott space ΣP is homeomorphic to X, where Max(P) is the set of all maximal points of P. Every T1 space has a (bounded complete algebraic) poset model. It was, however, not known whether every T1 space has a directed complete poset model and whether every sober T1 space has a directed complete poset model whose Scott topology is sober. In this paper we give a positive answer to each of these two problems. For each T1 space X, we shall construct a directed complete poset E that is a model of X, and prove that X is sober if and only if the Scott space Σ E is sober. One useful by-product is a method for constructing more directed complete posets whose Scott topology is not sober.

scholarly journals Dcpo models of T1 spaces

10.29007/prcv ◽  
2018 ◽  
Author(s):  
Zhao Dongsheng ◽  
Xi Xiaoyong
Keyword(s):  
Topological Space ◽  
Positive Answer ◽  
Scott Topology ◽  
Maximal Points

A poset model of a topological space X is a poset P such that the subspace Max(P) of the Scott space ΣP consisting of all maximal points of P is homeomorphic to X. Every T<sub>1</sub> space has a (bounded complete algebraic) poset model. It is, however, not known whether every T<sub>1</sub> space has a dcpo model and whether every sober T<sub>1</sub> space has a dcpo model whose Scott topology is sober. In this paper we give a positive answer to these two problems. For each T<sub>1</sub> space X we shall construct a dcpo A that is a model of X, and prove that X is sober if and only if the Scott topology of A is sober. One useful by-product is a method that can be used to construct more non-sober dcpos.

Lattice-valued Scott topology on dcpos

2015 ◽  
Vol 27 (4) ◽  
pp. 516-529
Author(s):  
WEI YAO
Keyword(s):  
Topological Space ◽  
Continuous Semigroup ◽  
Scott Topology ◽  
Completely Distributive ◽  
Sober Space ◽  
Truth Value

This paper studies the fuzzy Scott topology on dcpos with a *-continuous semigroup (L, *) as the truth value table. It is shown that the fuzzy Scott topological space on a continuous dcpo is an ιL-sober space. The fuzzy Scott topology is completely distributive iff L is completely distributive and the underlying dcpo is continuous. For (L, *) being an integral quantale, semantics of L-possibility of computations is studied by means of a duality.

Spaces of maximal points

1997 ◽  
Vol 7 (5) ◽  
pp. 543-555 ◽  
Author(s):  
JIMMIE LAWSON
Keyword(s):  
Metric Spaces ◽  
Scott Topology ◽  
Maximal Points

This paper shows that it is precisely the complete metrizable separable metric spaces that can be realized as the set of maximal points of an ω-continuous dcpo, where the set of maximal points is topologized with the relative Scott topology.

scholarly journals Scott convergence and fuzzy Scott topology on L-posets

2017 ◽  
Vol 15 (1) ◽  
pp. 815-827 ◽  
Author(s):  
Hongping Liu ◽  
Ling Chen
Keyword(s):  
Topological Space ◽  
Scott Topology ◽  
Convergence Structure

Abstract We firstly generalize the fuzzy way-below relation on an L-poset, and consider its continuity by means of this relation. After that, we introduce a kind of stratified L-generalized convergence structure on an L-poset. In terms of that, L-fuzzy Scott topology and fuzzy Scott topology are considered, and the properties of fuzzy Scott topology are discussed in detail. At last, we investigate the Scott convergence of stratified L-filters on an L-poset, and show that an L-poset is continuous if and only if the Scott convergence on it coincides with the convergence with respect to the corresponding topological space.

scholarly journals A new convergence inducing the SI-topology

Filomat ◽  
2018 ◽  
Vol 32 (17) ◽  
pp. 6017-6029 ◽  
Author(s):  
Hadrian Andradi ◽  
Chong Shen ◽  
Weng Ho ◽  
Dongsheng Zhao
Keyword(s):  
Topological Space ◽  
Domain Theory ◽  
Scott Topology ◽  
Convergence Structure ◽  
Equivalent Conditions

In their attempt to develop domain theory in situ T0 spaces, Zhao and Ho introduced a new topology defined by irreducible sets of a resident topological space, called the SI-topology. Notably, the SI-topology of the Alexandroff topology of posets is exactly the Scott topology, and so the SI-topology can be seen as a generalisation of the Scott topology in the context of general T0 spaces. It is well known that the convergence structure that induces the Scott topology is the Scott-convergence - also known as lim-inf convergence by some authors. Till now, it is not known which convergence structure induces the SI-topology of a given T0 space. In this paper, we fill in this gap in the literature by providing a convergence structure, called the SI-convergence structure, that induces the SI-topology. Additionally, we introduce the notion of I-continuity that is closely related to the SI-convergence structure, but distinct from the existing notion of SI-continuity (introduced by Zhao and Ho earlier). For SI-continuity, we obtain here some equivalent conditions for it. Finally, we give some examples of non-Alexandroff SI-continuous spaces.

scholarly journals Maximal point spaces of posets with relative lower topology

Filomat ◽  
2021 ◽  
Vol 35 (8) ◽  
pp. 2645-2661
Author(s):  
Chong Shen ◽  
Xiaoyong Xi ◽  
Dongsheng Zhao
Keyword(s):  
Topological Space ◽  
Domain Theory ◽  
New Models ◽  
Different Types ◽  
Maximal Point ◽  
Order Structures ◽  
Maximal Points

In domain theory, by a poset model of a T1 topological space X we usually mean a poset P such that the subspace Max(P) of the Scott space of P consisting of all maximal points is homeomorphic to X. The poset models of T1 spaces have been extensively studied by many authors. In this paper we investigate another type of poset models: lower topology models. The lower topology ?(P) on a poset P is one of the fundamental intrinsic topologies on the poset, which is generated by the sets of the form P\?x, x ? P. A lower topology poset model (poset LT-model) of a topological space X is a poset P such that the space Max?(P) of maximal points of P equipped with the relative lower topology is homeomorphic to X. The studies of such new models reveal more links between general T1 spaces and order structures. The main results proved in this paper include (i) a T1 space is compact if and only if it has a bounded complete algebraic dcpo LT-model; (ii) a T1 space is second-countable if and only if it has an ?-algebraic poset LT-model; (iii) every T1 space has an algebraic dcpo LT-model; (iv) the category of all T1 space is equivalent to a category of bounded complete posets. We will also prove some new results on the lower topology of different types of posets.

Homomorphisms on Function Algebras

1994 ◽  
Vol 46 (4) ◽  
pp. 734-745 ◽  
Author(s):  
M. I. Garrido ◽  
J. Gómez Gil ◽  
J. A. Jaramillo
Keyword(s):  
Banach Space ◽  
Topological Space ◽  
Wide Class ◽  
Rational Functions ◽  
Positive Answer ◽  
Algebra Homomorphism ◽  
Function Algebras ◽  
Real Analytic Functions ◽  
Real Analytic ◽  
Separable Spaces

AbstractLet A be an algebra of continuous real functions on a topological space X. We study when every nonzero algebra homomorphism φ: A → R is given by evaluation at some point of X. In the case that A is the algebra of rational functions (or real-analytic functions, or Cm-functions) on a Banach space, we provide a positive answer for a wide class of spaces, including separable spaces and super-reflexive spaces (with nonmeasurable cardinal).

scholarly journals RegularL-fuzzy topological spaces and their topological modifications

2000 ◽  
Vol 23 (10) ◽  
pp. 687-695 ◽  
Author(s):  
T. Kubiak ◽  
M. A. de Prada Vicente
Keyword(s):  
Topological Space ◽  
The Other ◽  
Regular Space ◽  
Continuous Lattice ◽  
Topological Spaces ◽  
Scott Topology ◽  
Fuzzy Topological Spaces

ForLa continuous lattice with its Scott topology, the functorιLmakes every regularL-topological space into a regular space and so does the functorωLthe other way around. This has previously been known to hold in the restrictive class of the so-called weakly induced spaces. The concepts ofH-Lindelöfness (á la Hutton compactness) is introduced and characterized in terms of certain filters. RegularH-Lindelöf spaces are shown to be normal.

Mars: was There an Ancient Eden?

1997 ◽  
Vol 161 ◽  
pp. 203-218 ◽  
Author(s):  
Tobias C. Owen
Keyword(s):  
Positive Answer ◽  
Biogenic Elements ◽  
Habitable Zones ◽  
The Face ◽  
The Origin Of Life ◽  
Early Mars ◽  
Favorable Conditions ◽  
Open Question ◽  
Rocky Planets ◽  
Impact Erosion

AbstractThe clear evidence of water erosion on the surface of Mars suggests an early climate much more clement than the present one. Using a model for the origin of inner planet atmospheres by icy planetesimal impact, it is possible to reconstruct the original volatile inventory on Mars, starting from the thin atmosphere we observe today. Evidence for cometary impact can be found in the present abundances and isotope ratios of gases in the atmosphere and in SNC meteorites. If we invoke impact erosion to account for the present excess of129Xe, we predict an early inventory equivalent to at least 7.5 bars of CO2. This reservoir of volatiles is adequate to produce a substantial greenhouse effect, provided there is some small addition of SO2(volcanoes) or reduced gases (cometary impact). Thus it seems likely that conditions on early Mars were suitable for the origin of life – biogenic elements and liquid water were present at favorable conditions of pressure and temperature. Whether life began on Mars remains an open question, receiving hints of a positive answer from recent work on one of the Martian meteorites. The implications for habitable zones around other stars include the need to have rocky planets with sufficient mass to preserve atmospheres in the face of intensive early bombardment.

ON SOME TYPES OF FUZZY ROUGH $\widehat{p}g$-KERNAL SETS IN FUZZY ROUGH TOPOLOGICAL SPACE

2020 ◽  
Vol 9 (3) ◽  
pp. 1421-1431
Author(s):  
S. Padmapriya ◽  
V. Naveena
Keyword(s):  
Topological Space
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