An Index Formula for Cauchy-Riemann Operators on Surfaces with Boundary Punctures

Abstract

We give a self-contained proof of a formula computing the Fredholm index for asymptotically non-degenerate Cauchy-Riemann operators on surfaces with boundary punctures using the method of large antilinear deformations. This method for computing the index was introduced in the case of closed surfaces by Taubes and generalized to the case with interior punctures by Gerig. One novel feature arising from our proof is that the Euler characteristic term in the index formula involves a non-standard weighted count of boundary zeros. We hope that this formulation of the index formula will be useful to other researchers.