abstract: I shall describe how models from quantum field theory, like the (supersymmetric) nonlinear sigma model, can be converted into geometric variational problems. Since these problems typically possess a noncompact invariance group, standard variational schemes do not apply. On the other hand, however, via Noether's theorem, these symmetries provide us with additional structure that help us with the analytical treatment. I shall argue that these problems, because of their rich and difficult structure, can play a pioneering for the development of new techniques in geometric analysis.