Canal-U_Ocms 21956 ENG Lu=f, for say f" style="position: relative;" tabindex="0" id="MathJax-Element-2-Frame">f compactly supported, by demanding that u" style="position: relative;" tabindex="0" id="MathJax-Element-3-Frame">u is supported at points which are reachable by forward, respectively backward, time-like or light-like curves. This property corresponds to causality. But it has been known for a long time that in certain settings, such as Minkowski space, there are other ways of solving wave equations, namely the Feynman and anti-Feynman solution operators (propagators). I will explain a general setup in which all of these propagators are inverses of the wave operator on appropriate function spaces, and also mention positivity properties, and the connection to spectral and scattering theory in Riemannian settings, as well as to the classical parametrix construction of Duistermaat and Hörmander.]]> LOMFRv1.0 image en mouvement LOMv1.0 content provider 2016-05-12 LOMv1.0 author 2016-05-12 LOMv1.0 LOMFRv1.0 video/mp4 3996856303 PT1H5M4S LOMv1.0 lecture LOMv1.0 doctorat LOMv1.0 no LOMv1.0 no LOMv1.0 ispartof URI https://www.canal-u.tv/producteurs/institut_fourier/colloquium_mathalp LOMv1.0 discipline LOMv1.0 discipline CDD 22e éd. DDC 22nd ed. 510