Long-range correlations in the electric signals that precede rupture

The Smoluchowski-Chapman-Kolmogorov functional equation is applied to the electric signals that precede rupture. The results suggest a non-Markovian character of the analyzed data. The rescaled range Hurst and detrended fluctuation analyses, as well as that related with the ``mean distance a walker spanned,'' lead to power-law exponents, which are consistent with the existence of long-range correlations. A ``universality'' in the power spectrum characteristics of these signals emerges, if an analysis is made (not in the conventional time frame, but) in the ``natural'' time domain. Within this frame, it seems that certain power spectrum characteristics of ion current fluctuations in membrane channels distinguish them from the electric signals preceding rupture. The latter exhibit a behavior compatible with that expected from a model based on the random field Ising Hamiltonian at the critical point.