The physics of neutrinos includes a plethora of modern research subjects covering a wide energy region such as GeV accelerator neutrino oscillations, solar and astrophysical neutrinos in the sub-MeV up to about 100 MeV region, neutrino-nucleon and neutrino-nucleus interactions, neutrino nucleosynthesis, double beta decays and tritium beta decays, neutrinos as dark matter, and many other topics.

The intensity frontier is a wide assortment of precision measurements for the properties of particles such as neutrinos, which may be well known, but have a long way to go before their parameters fully are understood. It is a multidirectional approach with global participation using multibillion, megawatt sources, and megaton and extremely quiet detectors. These methods will help us measure the neutrino parameters with very high sensitivity and clarify some of the fundamental questions still unanswered by the Standard Model.

The path forward to the New Physics, beyond the Standard Model, has been more well defined than ever and the neutrino sector parameters are for many the signposts that guide there. The awe-inspiring discoveries of the neutrino flavors and oscillations from the last two decades have opened the door. The current experiments have paved the way with their unprecedented sensitivity of the values of the mixing angles of theta-13 and the octant of theta-23. Even the mystery of the mass hierarchy of the neutrino masses is settling down after turbulent debates that finally favor the normal hierarchy defining the direction to the essential evidence of New Physics; the CP violation in the neutrino sector. Most of the effort is devoted to this goal within the community. In parallel, the testing of our theories on the neutrino masses will complement this effort by fundamentally understanding the origin; is the neutrino mass part of the SM in the form of a SUSY or extra dimensions type of extension or does it come from New Physics. Of course, there still may be answers that will surprise us all.

In this spirit, this Special Issue invites researchers in these fields to contribute with articles on the subjects. These can be original research articles as well as reviews of either the experimental or theoretical nature.

Potential topics include but are not limited to the following:

• Weak interactions beyond the Standard Model (symmetries, neutrino properties, non-standard neutrino interactions, neutrino scattering on leptons, nucleons and nuclei, CP violation)
• Neutrino-less double beta decays
• Neutrino-nucleus cross sections at finite temperatures
• Neutrino interactions as probes to neutron densities
• Many-body and effective theories in neutrino-nucleus scattering
• Coherent and incoherent neutrino-nucleus scattering
• Short baseline interactions and oscillations
• Neutrino floor at direct detection of dark matter
• Astrophysical neutrino sources and neutrino nucleo-synthesis