کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4658656 1633113 2014 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Remainders and cardinal invariants
موضوعات مرتبط
مهندسی و علوم پایه ریاضیات هندسه و توپولوژی
پیش نمایش صفحه اول مقاله
Remainders and cardinal invariants
چکیده انگلیسی

In this paper, we investigate remainders and cardinal invariants of some topological spaces (or semitopological groups, paratopological groups). The main results are: (1) If a non-locally compact homogeneous space X is locally ccc and X   has a remainder with a locally point-countable base, then w(X)⩽2ωw(X)⩽2ω; (2) If a nowhere locally compact space X   with locally a GδGδ-diagonal has a remainder that is a paracompact p  -space, then w(X)=ωw(X)=ω; (3) If a non-locally compact paratopological group G has a developable remainder Y  , then nw(G)=πw(G)=πw(Y)=ωnw(G)=πw(G)=πw(Y)=ω; (4) If a non-locally compact paratopological group G has a remainder Y   with a point-countable base, then w(G)=w(Y)=ωw(G)=w(Y)=ω; (5) If a semitopological group H is r-equivalent to a non-locally compact semitopological group G   that has a countable base, then w(H)=ωw(H)=ω. Among them, (2) generalizes a result by A.V. Arhangelʼskii [1, Theorem 4.2], (4) generalizes both A.V. Arhangelʼskiiʼs result [5, Theorem 10] and C. Liuʼs result [14, Theorem 3.1], and (5) generalizes a result by A.V. Arhangelʼskii [2, Theorem 4.7].

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Topology and its Applications - Volume 164, 1 March 2014, Pages 14–23
نویسندگان
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