The point in weak semiprojectivity and AANR compacta

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• 作者：Terry A. Loring ^{loring@math.unm.edu}
• 关键词：46L85 ; 54C55
• 刊名：Topology and its Applications
• 出版年：2012
• 出版时间：15 February 2012
• 年：2012
• 卷：159
• 期：3
• 页码：850-863
• 全文大小：244 K

文摘

We initiate the study of pointed approximative absolute neighborhood retracts. Our motivation is to generate examples of -algebras that behave in unexpected ways with respect to weak semiprojectivity. We consider both weak semiprojectivity (WSP) and weak semiprojectivity with respect to the class of unital -algebras (WSP1). For a non-unital -algebra, these are different properties.

One example shows a -algebra A can fail to be WSP while its unitization is WSP. Another example shows WSP1 is not closed under direct sums.