TS-DFM: energy-guided distillation cuts discrete flow matching to 8 steps with better perplexity
Trajectory-Shaped Discrete Flow Matching (TS-DFM) replaces the blind stochastic mid-step jumps used to build training trajectories with a lightweight 'energy compass' that selects more coherent continuations during distillation. On a 170M-parameter language model the TS-DFM student at 8 generation steps achieves 32% lower perplexity than its 1,024-step teacher while running 128× faster, with gains consistent across data sources and multiple evaluators; the shaping is applied only during training so inference cost is unchanged.