Spatiotemporal dynamics of relativistic beam-plasma instabilities

The dynamics of relativistic plasma outflows is central to understanding the emission of the most energetic astrophysical scenarios, from AGN jets to Gamma Ray Bursts. Plasma instabilities dictate how the kinetic and magnetic energy stored in the plasma gets channeled to high-energy particles powering its nonthermal emission. Kinetic simulations play a major role in the study of these nonlinear processes but are typically limited small scales. In this presentation I will introduce a new analytical model that captures, for the first time, the spatiotemporal dynamics and associated interplay of an entire family of streaming plasma instabilities (Current Filamentation Instability, Two-Stream Instability, Oblique Instability, Self-Modulation Instability) excited by relativistic particle beams/flows in an ambient plasma. Based on this model, we have developed a new quasi-static code suitable to capture the dynamics of relativistic plasma instabilities, showing an excellent agreement with both the analytical model and full-PIC codes. Remarkably, the new code can bring dramatic speed ups in computation, modeling the same system > 10^5 times faster than full-PIC simulations. This is enabling the modeling of highly relativistic and dilute systems, such as those relevant to blazar jets that were impossible to model kinetically before these advances.