English

On generalized imaginary $\mathrm{Spin}^c$-Killing spinors

Differential Geometry 2026-05-11 v1

Abstract

A non-trivial spinor field ψ\psi is called a generalized imaginary Spinc\mathrm{Spin}^c-Killing spinor if Xg,Aψ=iμXψ\nabla^{g,A} _X \psi = i\mu X \cdot \psi for all vector fields XX, where μ\mu is a real function that is not identically zero and g,A\nabla^{g,A} is the Spinc\mathrm{Spin}^c Levi-Civita connection with U(1)\mathrm{U}(1)-connection AA. Associated with ψ\psi is a vector field VV, the Dirac current, defined by g(V,X)=iXψ,ψg(V,X) = i \langle X\cdot \psi, \psi \rangle. We prove that if VV vanishes somewhere and dimM3\operatorname{dim} M \geq 3, the manifold is locally isometric to real hyperbolic space. When VV never vanishes and dimM3\operatorname{dim} M \geq 3, we obtain a global geometric description of all Spinc\mathrm{Spin}^c-Riemannian manifolds carrying such spinors, under the assumption that either the normalized Dirac current ξ=VV\xi = \frac{V}{|V|} is complete or the leaves of D=ker(ξ)\mathcal{D} = \ker(\xi^\flat) are complete. Finally, we reinterpret the case of type~I generalized imaginary Spinc\mathrm{Spin}^c-Killing spinors in terms of parallel spinors for a suitable connection with vectorial torsion.

Cite

@article{arxiv.2605.07813,
  title  = {On generalized imaginary $\mathrm{Spin}^c$-Killing spinors},
  author = {José Luis Carmona Jiménez},
  journal= {arXiv preprint arXiv:2605.07813},
  year   = {2026}
}
R2 v1 2026-07-01T12:57:53.946Z