H\"{o}lder estimates for Cauchy-Type Integrals and proper holomorphic   mappings of symmetric products
  We prove estimates in H\"{o}lder spaces for some Cauchy-type integral operators representing holomorphic functions in Cartesian and symmetric products of planar domains. As a consequence, we obtain information on the boundary regularity in H\"{o}lder spaces of proper holomorphic maps between symmetric products of planar domains. 
Evan Castle, Debraj Chakrabarti, David Gunderman, Ellen Lehet
math.CV