Marigonda, A.; Siconolfi, A. Metric formulae for nonconvex Hamilton-Jacobi equations and applications. (English) Zbl 1235.49059 Adv. Differ. Equ. 16, No. 7-8, 691-724 (2011). Summary: We consider the Hamilton-Jacobi equation \(H(x,Du)=0\) in \(\mathbb{R}^n\), with \(H\) not enjoying any convexity properties in the second variable. Our aim is to establish existence and nonexistence theorems for viscosity solutions of associated Dirichlet problems, find representation formulae and prove comparison principles. Our analysis is based on the introduction of a metric intrinsically related to the 0-sublevels of the Hamiltonian, given by an inf-sup game theoretic formula. We also study the case where the equation is critical; i.e., \(H(x,Du)=-\varepsilon\) does not admit any viscosity subsolution, for \(\varepsilon>0\). MSC: 49L25 Viscosity solutions to Hamilton-Jacobi equations in optimal control and differential games 35J20 Variational methods for second-order elliptic equations Keywords:Hamilton-Jacobi equation; viscosity solutions of Dirichlet problems; comparison principles PDFBibTeX XMLCite \textit{A. Marigonda} and \textit{A. Siconolfi}, Adv. Differ. Equ. 16, No. 7--8, 691--724 (2011; Zbl 1235.49059)