当前位置: X-MOL 学术J. Fixed Point Theory Appl. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Unavoidable complexes, via an elementary equivariant index theory
Journal of Fixed Point Theory and Applications ( IF 1.8 ) Pub Date : 2020-03-16 , DOI: 10.1007/s11784-020-0763-2
Duško Jojić , Wacław Marzantowicz , Siniša T. Vrećica , Rade T. Živaljević

The partition invariant \(\pi (K)\) of a simplicial complex \(K\subseteq 2^{[m]}\) is the minimum integer \(\nu \), such that for each partition \(A_1\uplus \cdots \uplus A_\nu = [m]\) of [m], at least one of the sets \(A_i\) is in K. A complex K is r-unavoidable if \(\pi (K)\le r\). We say that a complex K is almost r-non-embeddable in \({\mathbb {R}}^d\) if, for each continuous map \(f: \vert K\vert \rightarrow {\mathbb {R}}^d\), there exist r vertex disjoint faces \(\sigma _1,\cdots , \sigma _r\) of \(\vert K\vert \), such that \(f(\sigma _1)\cap \cdots \cap f(\sigma _r)\ne \emptyset \). One of our central observations (Theorem 2.1), summarizing and extending results of Schild et al. is that interesting examples of (almost) r-non-embeddable complexes can be found among the joins \(K = K_1*\cdots *K_s\) of r-unavoidable complexes.

中文翻译:

通过基本等变指数理论,不可避免的络合物

简单复数\(K \ subseteq 2 ^ {[m]} \)的分区不变变量\(\ pi(K)\)是最小整数\(\ nu \),因此对于每个分区\(A_1 \ UPLUS \ cdots \ UPLUS A_ \ NU = [M] \)的[]的组中,至少一个\(A_I \)是在ķ。如果\(\ pi(K)\ le r \),则复数Kr-不可避免的。我们说如果对于每个连续映射\(f:\ vert K \ vert \ rightarrow {\ mathbb {R},如果复数K几乎是r-不可嵌入\({\ mathbb {R}} ^ d \)} ^ d \),存在r顶点不相交面\(\西格玛_1,\ cdots,\西格玛_r \)\(\ VERTķ\ VERT \) ,使得\(F(\西格马_1)\帽\ cdots \帽F(\西格玛_r) \ ne \ emptyset \)。我们的主要观察之一(定理2.1),总结和扩展了Schild等人的结果。是的那有趣的例子(几乎)- [R -壬嵌入复合物可以被中发现加入\(K = K_1 * \ cdots * K_S \)- [R -unavoidable络合物。
更新日期:2020-03-16
down
wechat
bug