@article{Wang2026, 
author = {Hanfeng Wang and Jing Zhang},
title = {The source number of a Tychonoff space in its compactifications},
year = {2026},
journal = {Electronic Research Archive},
volume = {34},
number = {1},
pages = {424-432},
keywords = {source number, Nagami number, weight, network weight, compactification},
url = {https://www.sciopen.com/article/10.3934/era.2026020},
doi = {10.3934/era.2026020},
abstract = {The source number    s  o  (  X  ) of a Tychonoff space    X denotes the minimal cardinal    τ such that    X has an open source        S   in some compactification    b  X for which        |        S        |    ≤  τ. In this paper some properties of source numbers are studied. Among other things, we showed that the equalities    w  (  X  )  =  n  w  (  X  )  s  o  (  X  ) and    w  (  X  )  =  s  o  (  X  )  N  a  g  (  X  )  i  w  (  X  ) hold for every Tychonoff space    X, where    w  (  X  ),    n  w  (  X  ),    i  w  (  X  ),    N  a  g  (  X  ) denote the weight, network weight,    i-weight, and Nagami number of a space    X, respectively. Some corollaries about the two statements were obtained.}
}