Universal Constants and Energy Integral in Self-Organized Criticality Systems

Abstract

The occurrence frequency distributions of fluxes (F) and fluences or energies (E) observed in astrophysical observations are found to be consistent with the predictions of the fractal-diffusive self-organized criticality (FD-SOC) model, which predicts power law slopes with universal constants of $\alpha_F=(9/5)=1.80$ for the flux and $\alpha_E=(5/3)\approx 1.67$ for the fluence. The energy integrated over the power law-like (size distribution) energy range is found to be finite for these power law slopes with $\alpha_E < 2$, which refutes earlier claims of a divergent energy integral that has been postulated in the energy budget of solar and stellar nanoflare scenarios. The theoretial FD-SOC model approximates the microscopic cellular automaton models satisfactorily with the macroscopic scaling law of classical diffusion. The universal scaling laws predict the size distributions of numerous astrophysical phenomena, such as solar flares, stellar flares, coronal mass ejections (CME), auroras, blazars, galactic fast radio bursts (FRB), active galactic nuclei (AGN), gamma-ray bursts (GRB), soft gamma-ray repeaters (SGB), and black-hole systems (BH), while coherent solar radio bursts, random radio bursts, solar energetic partices (SEP), cosmic rays, and pulsar glitches require non-standard SOC models.