α-sober spaces via the orthogonal closure operator

Each ordinal alpha equipped with the upper topology is a T0-space. It is well known that for alpha=2 the reflective hull of alpha in Top0 is the subcategory of sober spaces. Here, we define alpha-sober space for every ordinal alpha in such a way that the reflective hull of alpha in Top0 is the subca...

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Detalhes bibliográficos
Autor principal: Sousa, Lurdes (author)
Formato: article
Idioma:eng
Publicado em: 2015
Assuntos:
Texto completo:http://hdl.handle.net/10400.19/2852
País:Portugal
Oai:oai:repositorio.ipv.pt:10400.19/2852
Descrição
Resumo:Each ordinal alpha equipped with the upper topology is a T0-space. It is well known that for alpha=2 the reflective hull of alpha in Top0 is the subcategory of sober spaces. Here, we define alpha-sober space for every ordinal alpha in such a way that the reflective hull of alpha in Top0 is the subcategory of alpha-sober spaces. Moreover, we obtain an order-preserving bijective correspondence between a proper class of ordinals and the corresponding (epi)reflective hulls. Our main tool is the concept of orthogonal closure operator, introduced by the authour in a previous paper.