CRITICAL FLUCTUATIONS OF THE FIELD-EMISSION CURRENT

The cross-correlation and spectral density functions of the adsorbate density fluctuations have been calculated at the transition temperatur e of a second order phase transition. Comparison with hydrodynamic flu ctuations was made. Our calculations showed that for t = 0 the cross-c orrelation functions of the critical fluctuations are positive for any distance between the probed regions (they decay with distance as x-1/ 4). The hydrodynamic cross-correlation functions for t = 0 are positiv e when the probed regions overlap and are zero when they are separated . The spectral density for the critical fluctuations reveals faster de cay for low frequencies in comparison with the hydrodynamic one.