期刊名称：International Journal of Mathematics and Mathematical Sciences
印刷版ISSN：0161-1712
电子版ISSN：1687-0425
出版年度：2005
卷号：2005
DOI：10.1155/IJMMS.2005.3387
出版社：Hindawi Publishing Corporation
摘要：A collection of results are presented which are loosely centered
around the notion of reflective subcategory. For example, it is
shown that reflective subcategories are orthogonality classes,
that the morphisms orthogonal to a reflective subcategory are
precisely the morphisms inverted under the reflector, and that
each subcategory has a largest “envelope” in the ambient
category in which it is reflective. Moreover, known results
concerning the envelopes of the category of sober spaces, spectral
spaces, and jacspectral spaces, respectively, are summarized and
reproved. Finally, attention is focused on the envelopes of one-object
subcategories, and examples are considered in the category of groups.
