## Bulletin of the Belgian Mathematical Society - Simon Stevin

### Lipsman mapping and dual topology of semidirect products

Aymen Rahali

#### Abstract

We consider the semidirect product $G = K \ltimes V$ where $K$ is a connected compact Lie group acting by automorphisms on a finite dimensional real vector space $V$ equipped with an inner product $\langle,\rangle$. We denote by $\widehat{G}$ the unitary dual of $G$ (note that we identify each representation $\pi\in\widehat{G}$ to its classes $[\pi]$) and by $\mathfrak{g}^\ddag/G$ the space of admissible coadjoint orbits, where $\mathfrak{g}$ is the Lie algebra of $G.$ It was pointed out by Lipsman that the correspondence between $\mathfrak{g}^\ddag/G$ and $\widehat{G}$ is bijective. Under some assumption on $G,$ we prove that the Lipsman mapping \begin{eqnarray*} \Theta:\mathfrak{g}^\ddag/G &\longrightarrow&\widehat{G}\\ \mathcal{O}&\longmapsto&\pi_\mathcal{O} \end{eqnarray*} is a homeomorphism.

#### Article information

Source
Bull. Belg. Math. Soc. Simon Stevin, Volume 26, Number 1 (2019), 149-160.

Dates
First available in Project Euclid: 20 March 2019

https://projecteuclid.org/euclid.bbms/1553047234

Digital Object Identifier
doi:10.36045/bbms/1553047234

Mathematical Reviews number (MathSciNet)
MR3934086

Zentralblatt MATH identifier
07060321

#### Citation

Rahali, Aymen. Lipsman mapping and dual topology of semidirect products. Bull. Belg. Math. Soc. Simon Stevin 26 (2019), no. 1, 149--160. doi:10.36045/bbms/1553047234. https://projecteuclid.org/euclid.bbms/1553047234