SHARPER TOTAL VARIATION BOUNDS FOR THE P-SYSTEM OF FLUID DYNAMICS.

For the p-system of fluid dynamics and under the assumption that the initial data have small oscillation but not necessarily small total variation, we reproduce the so-called Glimm-Lax estimates with greater accuracy. Our approach recovers the results known for smooth flux functions, and is based on the theory of generalized characteristics and Dafermos' technique of polygonal approximations. [ABSTRACT FROM AUTHOR]