Parametric resonance in neutrino oscillations in matter

Neutrino oscillations in matter can exhibit a specific resonance enhancemen t - parametric resonance, which is different from the MSW resonance. Oscill ations of atmospheric and solar neutrinos inside the earth can undergo para metric enhancement when neutrino trajectories cross the core of the earth. In this paper we review the parametric resonance of neutrino oscillations i n matter. In particular, physical interpretation of the effect and the pros pects of its experimental observation in oscillations of solar and atmosphe ric neutrinos in the earth are discussed.