Equivariant formality of istropy actions

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Carlson, Jeffrey D., Fok, Chi-Kwong
Format: Preprint
Published: 2015
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866909291860983808
author Carlson, Jeffrey D.
Fok, Chi-Kwong
author_facet Carlson, Jeffrey D.
Fok, Chi-Kwong
contents Let $G$ be a compact connected Lie group and $K$ a connected Lie subgroup. In this paper, we collect an assortment of results on equivariant formality of the isotropy action of $K$ on $G/K$. If the isotropy action of $K$ on $G/K$ is equivariantly formal, then $G/K$ is formal in the sense of rational homotopy theory. This enables us to strengthen a theorem of Shiga--Takahashi to a characterization of equivariant formality in this case. Using a K-theoretic analogue of equivariant formality introduced and shown by the second-named author to be equivalent to equivariant formality in the usual sense, we provide a representation-theoretic characterization for equivariant formality of the isotropy action and give a new, uniform proof of equivariant formality for some classes of homogeneous spaces for which it was previously known.
format Preprint
id arxiv_https___arxiv_org_abs_1511_06228
institution arXiv
publishDate 2015
record_format arxiv
spellingShingle Equivariant formality of istropy actions
Carlson, Jeffrey D.
Fok, Chi-Kwong
Algebraic Topology
K-Theory and Homology
55N25, 55N15, 19L47, 57T15
Let $G$ be a compact connected Lie group and $K$ a connected Lie subgroup. In this paper, we collect an assortment of results on equivariant formality of the isotropy action of $K$ on $G/K$. If the isotropy action of $K$ on $G/K$ is equivariantly formal, then $G/K$ is formal in the sense of rational homotopy theory. This enables us to strengthen a theorem of Shiga--Takahashi to a characterization of equivariant formality in this case. Using a K-theoretic analogue of equivariant formality introduced and shown by the second-named author to be equivalent to equivariant formality in the usual sense, we provide a representation-theoretic characterization for equivariant formality of the isotropy action and give a new, uniform proof of equivariant formality for some classes of homogeneous spaces for which it was previously known.
title Equivariant formality of istropy actions
topic Algebraic Topology
K-Theory and Homology
55N25, 55N15, 19L47, 57T15
url https://arxiv.org/abs/1511.06228