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8 votes
1 answer
3k views

The Quotients $SO(n)/SO(n-1)$, $O(n)/O(n-1)$ and $SO(n)/O(n−1)$

The branching laws for the restricted representation of $SO(n)$ with respect to the subgroup $SO(n-1)$ are discussed in this Wikipedia article. Am I correct in reading from this that any given ...
Lars Pettersen's user avatar
5 votes
1 answer
472 views

Finite dimensional homogeneous spaces of $Diff(S^1)$

This question is a refined version of Representations of infinite dimensional Lie algebras as vector fields on manifolds I'm interested in the finite dimensional homogeneous spaces of $Diff(S^1)$. ...
H. Arponen's user avatar
4 votes
2 answers
332 views

Does the maximal compact subgroup always act transitively on a compact homogeneous space?

Let $ G $ be a Lie group, $ H $ a closed subgroup, and $ G/H $ compact. Under what conditions do we have that $$ G/H \cong K/(K\cap H) $$ where $ K $ is a maximal compact subgroup of $ G $? Obviously ...
Ian Gershon Teixeira's user avatar
2 votes
1 answer
320 views

Gelfand pairs and (self)-dual representations

For a Lie group $G$ with compact Lie subgroup $K$, we say that $(G,K)$ is a pair of Gelfand type if the representation $L^2(G/K)$ of $G$ is multiplicity free, that is, if it is a direct integral of ...
Alesandro Levi's user avatar
2 votes
0 answers
125 views

The double quotient of SU(N) by its diagonal maximal torus

$\DeclareMathOperator\SU{SU}$The special unitary group $\SU(N)$ contains $T^{N-1}$ as a maximal torus, which we take to be the diagonal subgroup of $\SU(N)$. Can we describe the double quotient space $...
Yilmaz Caddesi's user avatar
2 votes
1 answer
262 views

From the representation category of a Lie group and the representation on a homogeneous space, can we reconstruct the stabiliser subgroup reps?

Given a Lie group $G$ and a transitive action $- \triangleright - : G \times X \to X$ on a homogeneous space, we can recover the stabiliser subgroup $H_x$ of a point $x \in X$. It is the subgroup of $...
Manuel Bärenz's user avatar