Modeling of Mrk 421 2013 flare. Observational data are presented at Hovatta et al. (2015). The parameter set that we use in this modeling are: cm, G, erg s⁻¹, , u_exp = 0.05 c, γ_min = 1, γ_max = 10^5.1, p = 2, δ = 10 and z₀ = 0.1 pc. Magnetic field decreases as B′∝R^{′ − 1}, and electron luminosity as . For the γ-ray flare, we used a pulse that was injected at  = 40 t_cross, 0, with a width w′ = 23 t_cross, 0, and α = 60.