Moebius Fermions
  We introduce a new domain wall operator that represents a full (real) Moebius transformation of a given non-chiral Dirac kernel. Shamir's and Borici's domain wall fermions are special cases of this new class. By tuning the parameters of the Moebius operator and by introducing a new Red/Black preconditioning, we are able to reduce the computational effort substantially. 
R. C. Brower, H. Neff, K. Orginos