Dispersion diagrams of the electrostatic waves along the magnetic field around the saturation time. Comparison between 1D (top row) and 2D (bottom row) simulations with the same plasma parameters. The solitons dispersion branches are denoted by black arrows and the superluminal L-mode waves by red arrows. The superluminal waves appear in 1D and 2D, while the soliton branch appears only in 1D. (a) S1–1D : ω_pt = 1500 − 2500. (b) S2–1D : ω_pt = 500 − 1500. (c) S3–1D : ω_pt = 4000 − 5000. (d) S1–2D : ω_pt = 2000 − 3000. (e) S2–2D : ω_pt = 1000 − 2000. (f) S3–2D : ω_pt = 3000 − 4000.