Small-scale cosmic microwave background fluctuations as a probe of the mass of dark matter particles

The CMB anisotropy on arcsecond scale is examined to test the power spectrum of perturbations in the small-scale region and to estimate the mass of dominant dark matter particles. It is shown that for the simplest evolutionary history with standard recombination, three- and four-beam observations with an antenna beam of approximate to 0.'5 and an amplitude approximate to(1 - 0.01) x 10(-7) could discriminate the mass of dark matter particles in the interval 0.5 keV less than or equal to M(DM) less than or equal to 2 keV. This dynamical range is the most interesting one for the problem of large-scale structure formation and evolution.