Geometrical Optics and Related Topics

Blowup of small data solutions for a class of quasilinear wave equations in two space dimensions - an outline of the proof, S. Alinhac; concentration effects in critical nonlinear wave equation and scattering theory, H. Bahouri and P. Gerard; lower semicontinuity of weighted path length in BV, P. Baiti and A. Bressan; time decay of Lp norms for solutions of the wave equation on exterior domains, M. Beals; Sobolev embeddings in Weyl-Hormander calculus, J-Y. Chemin and C-J. Xu; about the Cauchy problem for a system of conservation laws, C. Cheverry; global existance of the solutions and formation of singularities for a class of hyberbolic systems, D. DeL Santo, V. Georgiev and E. Mitidieri; a class of solvable operators, N. Dencker; uniqueness of the Cauchy problem under partial analyticity assumptions, L. Hormander; nonlinear wave diffraction, J.K. Hunter; caustics for dissipative semilinear oscillations, J-L. Joly, G. Metivier and J. Rauch; geometric optics and the bottom of the spectrum, R.B. Melrose; hypoellipticity for a class of infinately degenerate elliptic operators, Y. Morimoto and T. Morioka; regularity of solutions to characteristic boundary value problem for symmetric systems, T. Nishitani and M. Takayama.