MiS Preprint Repository

An entropy solution $u$ of a multi--dimensional scalar conservation law is not necessarily in $BV$, even if the conservation law is genuinely nonlinear. We show that $u$ nevertheless has the structure of a $BV$--function in the sense that the shock location is codimension--one rectifiable.

This result highlights the regularizing effect of genuine nonlinearity in a qualitative way; it is based on the locally finite rate of entropy dissipation. The proof relies on the geometric classification of blow--ups in the framework of the kinetic formulation.