The Circle Transfer and Cobordism Categories
The Circle Transfer and Cobordism Categories
复制标题
圆转移和共边范畴
DOI:
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发表时间:
2017
影响因子:
0.7
通讯作者:
Jeffrey Giansiracusa
中科院分区:
文献类型:
--
作者:
Jeffrey Giansiracusa
Abstract The circle transfer $QSigma (LX_{hS^1})_+ o QLX_+$ has appeared in several contexts in topology. In this note, we observe that this map admits a geometric re-interpretation as a morphism of cobordism categories of 0-manifolds and 1-cobordisms. Let ?1(X) denote the one-dimensional cobordism category and let Circ(X) ⊂ ?1(X) denote the subcategory whose objects are disjoint unions of unparametrized circles. Multiplication in S1 induces a functor Circ(X) → Circ(LX), and the composition of this functor with the inclusion of Circ(LX) into ?1(LX) is homotopic to the circle transfer. As a corollary, we describe the inclusion of the subcategory of cylinders into the two-dimensional cobordism category ?2(X) and find that it is null-homotopic when X is a point.