Rado numbers: SAT methods and connections to Nullstellensatz complexity
summary
Computations produce hundreds of new exact Rado numbers and a SAT method that generates SAT-based formulas for three infinite families of three‑color Rado numbers, using standard CDCL solvers (CaDiCaL) to find thousands of two‑color, a few hundred three‑color and about ten four‑color values with most 2–3 color instances solved in under a minute. A constructive reduction produces bounded Nullstellensatz certificates and proves Nullstellensatz degree ≤ online Rado number via Builder‑Painter games, with explicit gaps observed (e.g. Schur: degree 2 vs Rado 5).
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chapters (18)
- 0:00Introduction
- 1:40Origins of Ramsey Theory
- 2:26Schur's Theorem
- 3:57Van der Waerden's Theorem
- 4:33Van der Waerden numbers
- 5:58Rado numbers
- 6:46Rado's theorem
- 8:46SAT successes in Ramsey theory
- 11:08Three-variable equations
- 15:03SAT encoding
- 16:07SAT solving
- 18:132-color Generalized Schur Numbers
- 19:01Upper bounds: Variables indexed by polynomials
- 20:29Current work
- 24:55Polynomial encodings
- 26:11Hilbert's Nullstellensatz
- 27:01Online Ramsey numbers
- 29:45Future work
