GEOMETRIC SYMMETRY TECHNIQUES FOR PARTIAL DIFFERENTIAL EQUATIONS.

The article discusses a thesis that applies Vessiot theory and exterior calculus to find local solutions of partial differential equations (PDEs) and examines the classes of PDEs represented by vector fields forming Vessiot distribution. Topics discussed include the development and application of a method to find the largest integrable sub-distributions and solutions of PDEs and results about the Frobenius integrability and solution of evolution equations admitting travelling wave solutions.