Intrinsic convergence of the homological Taylor tower for $r$-immersions in $\mathbb R^n$

TL;DR

This paper investigates the convergence properties of the homological Taylor tower for the space of r-immersions in Euclidean space, providing connectivity calculations and comparisons with the homotopical tower.

Contribution

It computes the connectivity of the layers in the homological Taylor tower for r-immersions and establishes conditions for its convergence, also comparing it with the homotopical tower.

Findings

Connectivity of layers in the homological Taylor tower is explicitly calculated.

Conditions are identified under which the tower's maps become infinitely connected.

A Hurewicz isomorphism is shown between the homotopy groups of the homological and homotopical towers up to degree 2r-1.

Abstract

For an integer $r\ge 2$, the space of $r$-immersions of $M$ in $\R^n$ is defined to be the space of immersions of $M$ in $\R^n$ such that at most $r-1$ points of $M$ are mapped to the same point in $\R^n$. The space of $r$-immersions lies ``between" the embeddings and the immersions. We calculate the connectivity of the layers in the homological Taylor tower for the space of $r$-immersions in $\mathbb R^n$ (modulo immersions), and give conditions that guarantee that the connectivity of the maps in the tower approaches infinity as one goes up the tower. We also compare the homological tower with the homotopical tower, and show that up to degree $2r-1$ there is a ``Hurewicz isomorphism" between the first non-trivial homotopy groups of the layers of the two towers.