I am a physicist active in the field of general relativity and gravitation. I have published so far over 200 peer-reviewed articles. According to NASA/ADS, my h-index is, at present, 39, and I have over 3300 citations (self-citations excluded). I acted as a referee for the National Aeronautics and Space Administration (NASA), the European Space Agency (ESA), the former Particle Physics and Astronomy Research Council (PPARC), the National Center for Science and Technology Evaluation (NCSTE) of Kazakhstan, and the Czech Science Foundation (GACR). I received an invitation on behalf of the Royal Swedish Academy of Sciences to submit nominations for the Crafoord Prize 2006. I received a grant of the Young Researchers Project 2001 by the University of Bari in 2001. I was the recipient of an award by the Italian Physical Society (SIF) in 2003 for my scientific activity. I received the Scholarship Luigi Volta for the Study of Astronomy from the Centre for Scientific Culture Alessandro Volta in 2006. Elsevier awarded me two New Astronomy Top Cited Author Awards in 2010. I received the IFM Einstein-Galilei Award 2012 from the Institute for Theoretical Physics and Advanced Mathematics Einstein-Galilei in 2012. The Editors of the journal New Astronomy, published by Elsevier, selected me as one of the most valued reviewers for the years 2013 and 2014. In December 2013 and January 2014, I got qualified in the Abilitazione Scientifica Nazionale by the M.I.U.R. as an Associate Professor for Astronomy, Astrophysics, and Earth and Planetary Physics, and for Theoretical Physics of the Fundamental Interactions, respectively. In February 2015, I was included in the Top Italian Scientists (TIS) ranking, by the VIA-Academy. In late 2014, I was appointed Editor-in-Chief of the journal Universe, published by MDPI. I serve also as Associate Editor for the journals Frontiers in Astronomy and Space Sciences, section Cosmology, published by Frontiers, and Galaxies, published by MDPI.