AI 中文总结
研究有限子集空间\(\mathrm{Sub}_n X\)的欧拉特征,针对具有有限CW复形同伦型的空间\(X\),通过计算得出其欧拉特征的显式公式\(\chi(\mathrm{Sub}_n X)=\sum_{i = 1}^n \binom{\chi(X)}{i}\)。
AI 中文摘要
对于拓扑空间\(X\),有限子集空间\(\mathrm{Sub}_n X\)由\(X\)中基数至多为\(n\)的非空子集组成。我们计算了对于任何具有有限CW复形同伦型的空间\(X\),\(\mathrm{Sub}_n X\)的欧拉特征。得到显式公式\(\chi(\mathrm{Sub}_n X)=\sum_{i = 1}^n \binom{\chi(X)}{i}\)。
英文摘要
For a topological space $X$, the space of finite subsets $\mathrm{Sub}_n X$ consists of non-empty subsets of $X$ of cardinality at most $n$. We compute the Euler characteristic of $\mathrm{Sub}_n X$ for any space $X$ having the homotopy type of a finite CW complex. We obtain the explicit formula $χ(\mathrm{Sub}_n X) = \sum_{i=1}^n \binom{χ(X)}{i}$.