Lattice Simulation of Multi-Stream Inflation

We present the first lattice simulation to investigate the nature of multi-stream inflation. The simulation confirms the physical picture of multi-stream inflation, and with new findings in parameter space and field behaviors. Our simulation shows that gradient energy plays a significant role in multi-stream inflation. For a double field potential with a shifted Gaussian barrier, bifurcation probability is controlled by the shift distance with an error function relation. The bubbles created by bifurcation tend to be more spherical as bifurcation probability decreases. Also, the bifurcation is more likely to introduce oscillations of field values inside the bubbles than outside.