Neutrinos are weakly interacting, electrically neutral particles in the standard model of particle physics. These neutrinos are referred to as left-handed or active neutrinos and are classified into three flavors (electron, mu, and tau). Neutrino oscillation is the phenomenon that involves the oscillation of neutrinos between the three flavors. This phenomenon is also applied the oscillation of left-handed neutrinos into right-handed (sterile) neutrinos. The sterile neutrino is a hypothetical particle that does not interact with the weak force and only interacts through the gravitational force. This characteristic of the sterile neutrino makes it a very good dark matter candidate
