Do gravitational waves carry energy-momentum? A reappraisal

After direct detection gravitational radiation in 2015 many authors are publishing remakes of their old articles about this radiation. I decided to follow this line in my Lecture delivered at the Conference "Varcosmofun'16" (12-17 September 2016, Szczecin, Poland, EU). Namely, I have presented at this Conference an updated summary of my past articles on gravitational radiation. As a base for my presentation I have used mainly the article published in 2002 in Annalen der Physik \cite{Gar3} and the articles \cite{Gar4}. In these past articles I have showed that the real gravitational waves which possess a non-vanishing Riemann tensor always carry energy-momentum (and also angular momentum). Our proof have used canonical superenergy and supermomentum tensor for gravitational field in former articles and the averaged relative energy-momentum tensor in latter. In this article we confine to the energy-momentum only.