Determining the neutrino mass scale, hierarchy, and number of effective neutrino species are central goals in modern cosmology – along with elucidating the nature of the initial conditions, and constraining the key cosmological parameters. To this end, the cosmic web as traced by galaxies and quasars is an ideal laboratory for addressing these key scientific issues. Gaining a deeper understanding of the effects of neutrinos and dark radiation on structure formation at small scales are in fact necessary, to obtain robust constraints free from systematic biases. After a broad cosmological overview, I will present a study of the impact of massive neutrinos and more generally of the `dark sector’ on the intergalactic medium and on the high-redshift cosmic web, derived from a novel suite of hydrodynamical simulations. I will also discuss the current status of neutrino cosmology in the context of the SDSS-IV extended Baryon Oscillation Spectroscopic Suvey (eBOSS), and highlight prospects for future large-volume experiments - along with the connection with particle physics. 

BIO
Graziano Rossi is currently an Associate Professor in Cosmology and Astrophysics at Sejong University in Seoul, Korea. He is also the SDSS Lead Scientist and Advisory Council Representative and Voting Member for Sejong University, the chair of the eBOSS simulations working group, the Korean PI Scientist for LSST, the chair of the DESI Speakers’ Board, and an affiliated member of the Korea Institute for Advanced Study (KIAS), and of the Paris Center for Cosmolog Physics (PCCP). Prior to that, he was a Research Associate at the Institut de Recherche sur les Lois Fondamentales de l'Univers (IRFU), CEA-Saclay (France), and a Postdoctoral Research Fellow at the Korea Institute for Advanced Study. He graduated from the University of Pennsylvania (USA) in August 2008, with a Ph.D. degree in Astrophysics. He also received a M.Sc. degree in Physics from the University of Pittsburgh in December 2004, and a B.S. in Astronomy from the University of Padova (Italy) in May 2003. His primary research interests in theoretical, numerical, and observational cosmology are centered on neutrino science, dark energy, and primordial non-Gaussianity from the largescale structure of the Universe – with a focus on the Sloan Digital Sky Survey (SDSS) and on upcoming large-volume cosmological surveys (DESI, LSST, SKA, GMT). His most recent work is centered on the impact of neutrino masses on the formation of structures, and on the production of high-resolution hydrodynamical simulations with massive neutrinos.