On the cardinality of separable pseudoradial spaces

نویسندگان

چکیده

The aim of this paper is to consider questions concerning the possible maximum cardinality various separable pseudoradial (in short: SP) spaces. most intriguing question here if there in ZFC a regular (or just Hausdorff) SP space >c. While left open, we establish number non-trivial results that list below. It consistent with MA+c=ℵ2 countably tight and compact 2c. If κ measurable cardinal then forcing extension obtained by adding many Cohen reals, every has at c. κ>ℵ1 reals are added model GCH pseudocompact countable dense set isolated points c≤ℵ2 0-dimensional greater than

برای دانلود باید عضویت طلایی داشته باشید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Subspaces of pseudoradial spaces

We prove that every topological space (T0-space, T1-space) can be embedded in a pseudoradial space (in a pseudoradial T0-space, T1-space). This answers the Problem 3 in [2]. We describe the smallest coreflective subcategory A of Top such that the hereditary coreflective hull of A is the whole category Top.

متن کامل

Compact Spaces and the Pseudoradial Property, Ii

There is a model of set theory in which all compact spaces of weight at most ω2 are pseudoradial.

متن کامل

Compact Spaces and the Pseudoradial Property, I

We investigate two properties and their connection to the property of pseudoradiality in the context of compact spaces. The first is the WAP property introduced by P. Simon and the second is the א0-pseudoradial property introduced by B. Šapirovskii. We show that ♦ implies there is a compact space which is pseudoradial but not WAP. We show that there is a model in which CH fails and in which all...

متن کامل

On the cardinality of functionally Hausdorff spaces

In this paper two new cardinal functions are introduced and investigated. In particular the following two theorems are proved: (i) If X is a functionally Hausdorff space then |X| ≤ 2fs(X)ψτ (X); (ii) Let X be a functionally Hausdorff space with fs(X) ≤ κ. Then there is a subset S of X such that |S| ≤ 2 and X = S {clτθ(A) : A ∈ [S] }.

متن کامل

On the cardinality of Hausdorff spaces

The aim of this paper is to show, using the reflection principle, three new cardinal inequalities. These results improve some well-known bounds on the cardinality of Hausdorff spaces.

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

ژورنال

عنوان ژورنال: Topology and its Applications

سال: 2021

ISSN: ['1879-3207', '0166-8641']

DOI: https://doi.org/10.1016/j.topol.2021.107791