X-ray Thomson scattering absolute intensity from the f-sum rule in the imaginary-time domain oleh T. Dornheim, T. Döppner, A. D. Baczewski, P. Tolias, M. P. Böhme, Zh. A. Moldabekov, Th. Gawne, D. Ranjan, D. A. Chapman, M. J. MacDonald, Th. R. Preston, D. Kraus, J. Vorberger