# Wydawnictwa / Czasopisma IMPAN / Bulletin Polish Acad. Sci. Math. / Wszystkie zeszyty

## Fibrations in the Category of Absolute Neighborhood Retracts

### Tom 55 / 2007

Bulletin Polish Acad. Sci. Math. 55 (2007), 145-154 MSC: 54C55, 55U35, 55P30. DOI: 10.4064/ba55-2-5

#### Streszczenie

The category $\mathsf{Top}$ of topological spaces and continuous maps has the structures of a fibration category and a cofibration category in the sense of Baues, where fibration = Hurewicz fibration, cofibration = the usual cofibration, and weak equivalence = homotopy equivalence. Concentrating on fibrations, we consider the problem: given a full subcategory $\mathcal C$ of $\mathsf{Top}$, is the fibration structure of $\mathsf{Top}$ restricted to $\mathcal C$ a fibration category? In this paper we take the special case where $\cal C$ is the full subcategory $\mathsf{ANR}$ of $\mathsf{Top}$ whose objects are absolute neighborhood retracts. The main result is that $\mathsf{ANR}$ has the structure of a fibration category if fibration = map having a property that is slightly stronger than the usual homotopy lifting property, and weak equivalence = homotopy equivalence.

#### Autorzy

• Takahisa MiyataDepartment of Mathematics and Informatics
Graduate School of Human Development and Environment
Kobe University
Kobe, 657-8501, Japan
e-mail

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