Hardy spaces for the conjugated Beltrami equation in a doubly connected domain

We consider Hardy spaces associated to the conjugated Beltrami equation on doubly connected planar domains. There are two main differences with previous studies (Baratchart et al., 2010 [2], ). First, while the simple connectivity plays an important role in Baratchart et al. (2010) [2], , the multiple connectivity of the domain leads to unexpected difficulties. In particular, we make strong use of a suitable parametrization of an analytic function in a ring by its real part on one part of the boundary and by its imaginary part on the other. Then, we allow the coefficient in the conjugated Beltrami equation to belong to W1,q for some q∈(2,+∞], while it was supposed to be Lipschitz in Baratchart et al. (2010) [2]. We define Hardy spaces associated with the conjugated Beltrami equation and solve the corresponding Dirichlet problem. The same problems for generalized analytic function are also solved.