Formation of singularities for certain hyperbolic systems in one space dimension

We study the development of singularities of classical solutions of quasilinear strictly hyperbolic systems in one space dimension. The systems are supposed to be in the diagonal form, but we do not impose restrictions on the size of the initial data and, in some cases, we can replace the genuine nonlinearity by weaker conditions.  2002 Elsevier Science (USA). All rights reserved.