Izumiya, Shyuichi; Kossioris, Georgios T. Semi-local classification of geometric singularities for Hamilton-Jacobi equations. (English) Zbl 0837.35091 J. Differ. Equations 118, No. 1, 166-193 (1995). The authors consider the Cauchy problem for Hamilton-Jacobi equations and study the generation and propagation of singularities appearing in the solutions. To consider this problem, the first author [Adv. Stud. Pure Math. 22, 89-100 (1993; reviewed above)] defined a notion of “geometric solution” in a framework of one parameter Legendrian unfoldings. On the other hand, the theory of viscosity solutions assured the global existence of weak solutions which satisfy the supplementary condition. Singularities of viscosity solutions correspond to the intersection of branches of a graph of multivalued geometric solutions. The principal part of this paper is as follows: To study the bifurcation of the branches of its graph, they formulated the problem in terms of multi- Legendrian unfoldings and gave the generic list of the bifurcations of the branches of the multivalued graph. The construction of singularities of weak solutions is not mentioned here. But they announce to publish a paper on this subject. Reviewer: M.Tsuji (Kyoto) Cited in 2 ReviewsCited in 4 Documents MSC: 35L67 Shocks and singularities for hyperbolic equations 35F25 Initial value problems for nonlinear first-order PDEs 58C25 Differentiable maps on manifolds 58K99 Theory of singularities and catastrophe theory 76L05 Shock waves and blast waves in fluid mechanics Keywords:Hamilton-Jacobi equations; viscosity solutions; geometric solutions; multi-Legendrian unfoldings PDFBibTeX XMLCite \textit{S. Izumiya} and \textit{G. T. Kossioris}, J. Differ. Equations 118, No. 1, 166--193 (1995; Zbl 0837.35091) Full Text: DOI Link