The Equivariant Second Yamabe Constant
  For a closed Riemannian manifold of dimension $n\geq 3$ and a subgroup $G$ of the isometry group, we define and study the $G-$equivariant second Yamabe constant and we obtain some results on the existence of $G-$invariant nodal solutions of the Yamabe equation. 
Guillermo Henry, Farid Madani
math.DG