... Local conservation lawsIn this section we record some standard facts about the (non)conservationof mass, momentum and energy densities for general nonlinear Schr¨odinger equations of the form6i∂tφ ... Lin and W. Strauss, Decay and scattering of solutions of a nonlinear Schr¨odinger equation, J. Funct. Anal. 30, (1978), 245–263.[34]C. Morawetz, Time decay for the nonlinear Klein-Gordon equation, ... 451–454.[36]J. Rauch, The u5Klein-Gordon equation. II. Anomalous singularities for semilinearwave equationsx, in Nonlinear Partial Differential Equations and their Applications,Coll`ege de France...