Radio-loud AGN are characterized by plasma jets that are formidable particle accelerators. In blazars we observe jets at a small angle with respect to the line of sight, with consequent relativistic Doppler beaming of the jet radiation. Therefore, the extremely variable jet emission dominates the spectral energy distribution of blazars from the radio band up to the gamma rays. I will review...
One of the main scenarios to account for the multi-wavelength flux variability observed in relativistic jets of active galactic nuclei (AGNs) is based on diffusive shock acceleration of a population of relativistic electrons on internal shocks of various origins. To understand the physical processes associated with the observed multi-wavelength emission maps and
light curves, we investigate...
I will show the results of the study of variability for a sample of more than 300 FSRQ in gamma-ray, focusing on waiting time between flares (L....
The characteristic variability of blazars is being since long time explained by relating it to a wide range of possible physical processes, occurring in the accretion disk and/or the jet. The various scenarios include emission spots in the accretion disk revolving around the supermassive black hole, magnetohydrodynamic instabilities in the disk or the jet, shocks traveling along turbulent...
