Cas d'existence de solutions d'EDP

We give some examples of the existence of solutions of geometric PDEs (Yamabe equation, Prescribed Scalar Curvature Equation, Gaussian curvature). We also give some remarks on second order PDE and Green functions and on the maximum principles. And on Harnack type inequalities and Sobolev and interpolation inequality and Moser-Trudinger inequality. And some remarks on the equations.