On the rational homology of high dimensional analogues of spaces of long knots

Abstract

We study high-dimensional analogues of spaces of long knots. These are spaces of compactly-supported embeddings (modulo immersions) of $\mathbb{R}^m$ into $\mathbb{R}^n$. We view the space of embeddings as the value of a certain functor at $\mathbb{R}^m$, and we apply manifold calculus to this functor. Our first result says that the Taylor tower of this functor can be expressed as the space of maps between infinitesimal bimodules over the little disks operad. We then show that the formality of the little disks operad has implications for the homological behavior of the Taylor tower. Our second result says that when $2m+1<n$, the singular chain complex of these spaces of embeddings is rationally equivalent to a direct sum of certain finite chain complexes, which we describe rather explicitly.Comment: This is a substantial rewrite of the previous version, incorporating suggestions of two referees. We simplified the description of the category representing infinitesimal bimodules (called "weak bimodules" in the previous version). We also eliminated all mentions of discretized operads, and our results are now formulated in terms of modules over the standard little disks opera