A mean field problem approach for the double curvature prescription problem

In this paper we establish a new mean field-type formulation to study the problem of prescribing Gaussian and geodesic curvatures on compact surfaces with boundary, which is equivalent to the following Liouville-type PDE with nonlinear Neumann conditions: $$\left\{\begin{array}{ll} -\Delta u+2K_g=2Ke^u&\text{in }\Sigma\\ \partial_\nu u+2h_g=2he^\frac u2&\text{on }\partial\Sigma. \end{array}\right.$$ We provide three different existence results in the cases of positive, zero and negative Euler characteristics by means of variational techniques.