Ziqin Feng

activity

20092023

most cited

P

-bases and Topological Groups

2 citations · 5 across the 12 of their papers we have counts for

collaborators

Showing math.GNShow all

10 papers · 1 filter

math.GN2021

Sub-posets in $ω^{ω}$ and the Strong Pytkeev $^{*}$ Property

Ziqin Feng, Naga Chandra Padmini Nukala

Tukey order are used to compare the cofinal complexity of partially order sets (posets). We prove that there is a $2^{c}$ -sized collection of sub-posets in $2^{ω}$ which for…

math.GN2020★ 2 cited

$P$ -bases and Topological Groups

Ziqn Feng

A topological space $X$ is defined to have a neighborhood $P$ -base at any $x \in X$ from some poset $P$ if there exists a neighborhood base $(U_{p} [x])_{p \in P}$ at $x$ such that $U_p…

math.GN2020

Compact Spaces with a $P$ -base

Alan Dow, Ziqin Feng

In the paper, we investigate (scattered) compact spaces with a $P$ -base for some poset $P$ . More specifically, we prove that, under the assumption $ω_{1} < b$ , any compact s…

math.GN2019★ 1 cited

Continuous Selections of Lower semicontinuous Set-valued Mappings

Ziqin Feng, Gary Gruenhage, Rongxin Shen

A space $X$ is strongly $Y$ -selective (resp., $Y$ -selective) if every lower semicontinuous mapping from $Y$ to the nonempty subsets (resp., nonempty closed subsets) of $X$ has a co…

math.GN2017

Spaces with a $Q$ -diagonal

Ziqin Feng

A space $X$ has a $Q$ -diagonal if $X^{2} ∖ Δ$ has a $K (Q)$ -directed compact cover. We show that any compact space with a $Q$ -diagonal is m…

math.GN2015

Spaces l-Dominated by I or R

Paul Gartside, Ziqin Feng

If $X$ is compact metrizable and has finite fd-height then the unit interval, $I$ , $ℓ$ -dominates $X$ , in other words, there is a continuous linear map of $C_{p} (I)$ onto $C_{p} (X)$ .…

Sub-posets in ωω and the Strong Pytkeev∗ Property

P-bases and Topological Groups

Compact Spaces with a P-base