Time Variations of the Superkamiokande Solar Neutrino Flux Data
  We have used the Date-Compensated Discrete Fourier Transform and Periodogram analysis of the solar neutrino flux data from 1) 5-day-long samples from Super-Kamiokande-I detector during the period from June, 1996 to July, 2001; 2) 10-day-long samples from the same detector during the same period and 3) 45-day-long samples from the same detector during the same period. (1) exhibits periodicity around 0.21-0.22, 0.67-0.77, 1.15-1.98, 6.72-6.95, 12.05-13.24, 22.48-24.02, 33.50 and 40.73 months. (2) shows periodicity around 0.39-0.45, 1.31-2.23, 5.20-5.32, 9.43-11.65, 13.54-14.38, 24.54, 32.99 and 41.69 months. For (3) we observe periodicity around 1.61, 14.01, 24.06, 32.50 and 42.03 months. We have found almost similar periods in the solar flares, sunspot data, solar proton data (\bar{\epsilon}>10 Mev) which indicates that the solar activity cycle may be due to the variable character of nuclear energy generation inside the sun. 
Abu Salem Mandal, Koushik Ghosh, Probhas Raychaudhuri