Published online by Cambridge University Press: 27 March 2014
A compact semisimple Lie algebra $\mathfrak{g}$ induces a Poisson structure
$\pi _{\mathbb{S}}$ on the unit sphere
$\mathbb{S}(\mathfrak{g}^*)$ in
$\mathfrak{g}^*$. We compute the moduli space of Poisson structures on
$\mathbb{S}(\mathfrak{g}^*)$ around
$\pi _{\mathbb{S}}$. This is the first explicit computation of a Poisson moduli space in dimension greater or equal than three around a degenerate (i.e. not symplectic) Poisson structure.