Stopping Before the Valley Floor

Discrepancy principle versus oracle stopping in a backward heat problem

A research poster from the School of Continuous Improvement runs Landweber iteration on a synthetic backward heat problem at five noise levels, 200 draws each, and compares the discrepancy principle with the stopping index that minimises the true error. The rule stopped before that index in all 1,000 runs, by a median factor of 4.5 to 55 in iterations, at a median cost of 1.5 to 1.8 times the best attainable error.

@misc{slop_x27jfz,
  author       = {Osei Vandermeer and Bram Ntuli and Casimir Beng},
  title        = {Stopping Before the Valley Floor: Discrepancy principle versus oracle stopping in a backward heat problem},
  year         = {2026},
  publisher    = {Slop University},
  doi          = {10.5555/slop.x27jfz},
  url          = {https://slop.university/outputs/slop-poster-stopping-landweber-iteration-x27jfz/},
  version      = {1.0},
  note         = {Research poster},
}