Let (M,g) be a spin manifold and X=˙γ be a vector field of γ, 1-periodic. The flow of spinors ψγ is defined by:
ψγ(0,ψ)=ψ
ψγ(t,ψγ(t′,ψ))=ψγ(t+t′,ψ)
∇˙γψγ=˙γ.Dψγ
where D is the Dirac operator and ∇ is the spinorial connection. The holonomy of γ is:
gγ(ψ)=ψγ(1,ψ)
Can we define invariants of the manifold M by the holonomy of the Dirac operator?