# Stabilization of the homotopy groups of the self equivalences of linear spheres

## TL;DR

This paper proves that the homotopy groups of the space of $G$-equivariant self-maps of linear spheres stabilize and describes their stable structure in terms of classifying spaces of isotropy groups.

## Contribution

It establishes the stabilization of homotopy groups for self-equivalence spaces of linear spheres under certain representation conditions and characterizes the stable groups explicitly.

## Key findings

- Homotopy groups stabilize as the dimension increases.
- Stable groups are described as direct sums over conjugacy classes of isotropy groups.
- Provides a formula for the stable homotopy groups in terms of classifying spaces.

## Abstract

Let $G$ be a finite group. Let $U_1,U_2,\dots$ be a sequence of orthogonal representations in which any irreducible representation of $\oplus_{n \geq 1} U_n$ has infinite multiplicity. Let $V_n=\oplus_{i=1}^n U_n$ and $S(V_n)$ denote the linear sphere of unit vectors. Then for any $i \geq 0$ the sequence of group $\dots \rightarrow \pi_i \operatorname{map}^G(S(V_n),S(V_n)) \rightarrow \pi_i \operatorname{map}^G(S(V_{n+1}),S(V_{n+1})) \rightarrow \dots$ stabilizes with the stable group $\oplus_H \omega_i(BW_GH)$ where $H$ runs through representatives of the conjugacy classes of all the isotropy group of the points of $S(\oplus_n U_n)$.