A fixed-point formula for Dirac operators on Lie groupoids
Ahmad Reza Haj Saeedi Sadegh, Shiqi Liu, Yiannis Loizides, Jesus Sanchez
Mathematics, Differential Geometry, Differential Geometry (math.DG), K-Theory and Homology (math.KT)
We study equivariant families of Dirac operators on the source fibers of a Lie groupoid with a closed space of units and equipped with an action of an auxiliary compact Lie group. We use the Getzler rescaling method to derive a fixed-point formula for the pairing of a trace with the K-theory class of such a family. For the pair groupoid of a closed manifold, our formula reduces to the standard fixed-point formula for the equivariant index of a Dirac operator. Further examples involve foliations and manifolds equipped with a normal crossing divisor.