Umberto De Giovannini

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Many works related learning from examples to regularization techniques for inverse problems, emphasizing the strong algorithmic and conceptual analogy of certain learning algorithms with regularization algorithms. In particular it is well known that regularization schemes such as Tikhonov regularization can be effectively used in the context of learning and(More)
W. Siu,1 F. Kelkensberg,1 G. Gademann,1 A. Rouzée,1,2 P. Johnsson,1,3 D. Dowek,4 M. Lucchini,5 F. Calegari,5 U. De Giovannini,6 A. Rubio,6 R. R. Lucchese,7 H. Kono,8 F. Lépine,9 and M. J. J. Vrakking1,2 1FOM Institute AMOLF, Science Park 104, NL-1098 XG Amsterdam, The Netherlands 2Max-Born-Institut, Max-Born Strasse 2A, D-12489 Berlin, Germany 3Department(More)
Many works have shown that strong connections relate learning from examples to regularization techniques for ill-posed inverse problems. Nevertheless by now there was no formal evidence neither that learning from examples could be seen as an inverse problem nor that theoretical results in learning theory could be independently derived using tools from(More)
We show that the energetics and lifetimes of resonances of finite systems under an external electric field can be captured by Kohn–Sham density functional theory (DFT) within the formalism of uniform complex scaling. Properties of resonances are calculated self-consistently in terms of complex densities, potentials and wavefunctions using adapted versions(More)
Angel Rubio‡ University of the Basque Country UPV/EHU, Nano-Bio Spectroscopy Group, Avenida de Tolosa 72, 20018 San Sebastian, Spain and Max Planck Institute for the Structure and Dynamics of Matter, Luruper Chaussee 149, 22761 Hamburg, Germany. Center for Free-Electron Laser Science and Department of Physics, University of Hamburg, Luruper Chaussee 149,(More)
Using time dependent density functional theory (TDDFT) we examine the energy, angular and timeresolved photoelectron spectra (TRPES) of ethylene in a pump-probe setup. To simulate TRPES we expose ethylene to an ultraviolet (UV) femtosecond pump pulse, followed by a time delayed extreme ultraviolet (XUV) probe pulse. Studying the photoemission spectra as a(More)
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