Table of contents : Propagation des singularites des solutions d’equations analogues a l’equation de Schrödinger....Pages 1-14 On the spectrum of positive elliptic operators and periodic bicharacteristics....Pages 15-22 Clean intersection theory and Fourier Integrals....Pages 23-35 Non-uniqueness for the Cauchy Problem....Pages 36-72 Solutions asymptotiques et groupe symplectique....Pages 73-97 Le polynome de Bernstein d’une singularite isolee....Pages 98-119 Fourier integral operators with complex-valued phase functions....Pages 120-223 On a problem of Hans Lewy....Pages 224-234 On structures of L 2 -well-posed mixed problems for hyperbolic operators....Pages 235-254 Applications of fourier distributions with complex phase functions....Pages 255-282 Second-order fuchsian elliptic equations and eigenvalue asymptotics....Pages 283-340 On Maslov’s quantization condition....Pages 341-372