Dynamical efficiency of collisionless magnetized shocks in relativistic jets

The so-called internal shock model aims to explain the light-curves and spectra produced by non-thermal processes originated in the flow of blazars and gamma-ray bursts. A long standing question is whether the tenuous collisionless shocks, driven inside a relativistic flow, are efficient enough to explain the amount of energy observed as compared with the expected kinetic power of the outflow. In this work we study the dynamic efficiency of conversion of kinetic-to- thermal/magnetic energy of internal shocks in relativistic magnetized outflows. We find that the collision between shells with a non-zero relative velocity can yield either two oppositely moving shocks (in the frame where the co…