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The Lumenary
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Experimental mathematics: conjectures and counterexamples

Using computation to discover patterns, generate conjectures and search for counterexamples: integer sequences and the OEIS, integer-relation algorithms such as PSLQ, exhaustive search, and computer-assisted proofs, with honest reporting of evidence.

math.comp.experimental-mathematics

Se basa en

Requisitos previos obligatorios, hasta el fondo: 43

Aprenderás a

  • Generate and test conjectures numerically, and design a counterexample search with clearly stated bounds.
  • Use high-precision arithmetic and integer-relation detection to guess closed forms, and then look for proofs.
  • Assess computer-assisted proofs, such as those of the four colour theorem and the Kepler conjecture, and how they were verified.

Definición

  • An integer relation among real numbers x₁, …, xₙ is a non-zero integer vector (a₁, …, aₙ) with a₁x₁ + ⋯ + aₙxₙ = 0.
  • A counterexample search is exhaustive up to a bound if it checks every case below that bound.

Teorema

  • The Bailey–Borwein–Plouffe formula for π was found with the help of the PSLQ integer-relation algorithm.
  • Hales's proof of the Kepler conjecture was formally verified by the Flyspeck project, completed in 2014.
  • Numerical evidence can mislead: π(x) < li(x) for every x that has been checked, yet Littlewood proved that the inequality reverses infinitely often.

Errores frecuentes

  • Treating a pattern that holds in many cases as established.
  • Reporting a search as exhaustive without stating its bounds.

Descubrimientos opcionales

Itinerarios de aprendizaje

Lecturas complementarias

  • Jonathan Borwein and David Bailey, Mathematics by Experiment: Plausible Reasoning in the 21st Century (2004)