Nonlinear O(n+1)-symmetric field theories, symmetry breaking and finite energy solutions

A class of O(n+1)-symmetric, nonlinear field theories, containing the standard chiral models as special cases is introduced. The class is parametrized by a function α and explicit transformations are given between any two theories corresponding to different choices of the function α. Classical 'plane wave' and static solutions of the equations of motions of these theories are exhibited. However symmetry breaking potentials have to be introduced to find solutions leading to a finite total energy. (Auth.)