Cauchy spaces

1970 ◽  
Vol 187 (3) ◽  
pp. 175-186 ◽  
Author(s):  
J. F. Ramaley ◽  
Oswald Wyler
Keyword(s):  
1987 ◽  
Vol 10 (2) ◽  
pp. 209-216
Author(s):  
D. C. Kent ◽  
Reino Vainio

A Cauchy structure and a preorder on the same set are said to be compatible if both arise from the same quasi-uniform convergence structure onX. Howover, there are two natural ways to derive the former structures from the latter, leading to “strong” and “weak” notions of order compatibility for Cauchy spaces. These in turn lead to characterizations of strong and weak order compatibility for convergence spaces.


2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
R. A. Hibschweiler

The operators D C Φ and C Φ D are defined by D C Φ f = f ∘ Φ ′ and C Φ D f = f ′ ∘ Φ where Φ is an analytic self-map of the unit disc and f is analytic in the disc. A characterization is provided for boundedness and compactness of the products of composition and differentiation from the spaces of fractional Cauchy transforms F α to the Bloch-type spaces B β , where α > 0 and β > 0 . In the case β < 2 , the operator D C Φ : F α ⟶ B β is compact ⇔ D C Φ : F α ⟶ B β is bounded ⇔ Φ ′ ∈ B β , Φ Φ ′ ∈ B β and Φ ∞ < 1 . For β < 1 , C Φ D : F α ⟶ B β is compact ⇔ C Φ D : F α ⟶ B β is bounded ⇔ Φ ∈ B β and Φ ∞ < 1 .


1984 ◽  
Vol 36 (1) ◽  
pp. 58-70 ◽  
Author(s):  
Eva Lowen-Colebunders

Cauchy spaces were introduced by Kowalsky in 1954 [9]. In that paper a first completion method for these spaces was given. In 1968 Keller [5] has shown that the Cauchy space axioms characterize the collections of Cauchy filters of uniform convergence spaces in the sense of [1]. Moreover in the completion theory of uniform convergence spaces the associated Cauchy structures play an essential role [12]. This fact explains why in the past ten years in the theory of Cauchy spaces, much attention has been given to the study of completions.


1987 ◽  
Vol 27 (2) ◽  
pp. 105-112 ◽  
Author(s):  
H.L. Bentley ◽  
H. Herrlich ◽  
E. Lowen-Colebunders

1999 ◽  
Vol 22 (3) ◽  
pp. 497-509
Author(s):  
J. Wig ◽  
D. C. Kent

The duality between “regular” and “topological” as convergence space properties extends in a natural way to the more general properties “p-regular” and “p-topological.” Since earlier papers have investigated regular,p-regular, and topological Cauchy completions, we hereby initiate a study ofp-topological Cauchy completions. Ap-topological Cauchy space has ap-topological completion if and only if it is “cushioned,” meaning that each equivalence class of nonconvergent Cauchy filters contains a smallest filter. For a Cauchy space allowing ap-topological completion, it is shown that a certain class of Reed completions preserve thep-topological property, including the Wyler and Kowalsky completions, which are, respectively, the finest and the coarsestp-topological completions. However, not allp-topological completions are Reed completions. Several extension theorems forp-topological completions are obtained. The most interesting of these states that any Cauchy-continuous map between Cauchy spaces allowingp-topological andp′-topological completions, respectively, can always be extended to aθ-continuous map between anyp-topological completion of the first space and anyp′-topological completion of the second.


1970 ◽  
Vol 187 (3) ◽  
pp. 187-199 ◽  
Author(s):  
J. F. Ramaley ◽  
Oswald Wyler
Keyword(s):  

1985 ◽  
Vol 8 (3) ◽  
pp. 483-496 ◽  
Author(s):  
D. C. Kent ◽  
R. Vainio

This paper is concerned with the notion of “ordered Cauchy space” which is given a simple internal characterization in Section 2. It gives a discription of the category of ordered Cauchy spaces which have ordered completions, and a construction of the “fine completion functor” on this category. Sections 4 through 6 deals with certain classes of ordered Cauchy spaces which have ordered completions; examples are given which show that the fine completion does not preserve such properties as uniformizability, regularity, or total boundedness. From these results, it is evident that a further study of ordered Cauchy completions is needed.


2005 ◽  
Vol 2005 (24) ◽  
pp. 4019-4027
Author(s):  
Nandita Rath
Keyword(s):  

The well-known completions ofT2Cauchy spaces andT2filter spaces are extended to the completions of non-T2filter spaces, and a completion functor on the category of all filter spaces is described.


2011 ◽  
Vol 133 (1-2) ◽  
pp. 14-32 ◽  
Author(s):  
Muammer Kula
Keyword(s):  

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