A perturbation method for spinorial Yamabe type equations on $$S^m$$ and its application

Abstract

For \(m\ge 2\), we prove the existence of non-trivial solutions for a certain kind of nonlinear Dirac equations with critical Sobolev nonlinearities on \(S^m\) via a perturbative variational method. For the special case \(m=2\), this establishes the existence of a conformal immersion \(S^2\rightarrow \mathbb R ^3\) with prescribed mean curvature \(H\) which is close to a positive constant under an index counting condition on \(H\).