Discrepancy theory

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Discrepancy theory can be described as the study of inevitable irregularities of distributions, in measure-theoretic and combinatorial settings. Just as Ramsey theory elucidates the impossibility of total disorder, discrepancy theory studies the deviations from total uniformity.

Contents

[edit] History

[edit] Classic theorems

  • Axis-parallel rectangles in the plane (Roth, Schmidt)
  • Discrepancy of half-planes (Alexander, Matousek)
  • Arithmetic progressions (Roth, Sarkozy, Beck, Matousek & Spencer)
  • Beck-Fiala theorem
  • Six Standard Deviations Suffice (Spencer)

[edit] Major open problems

  • Axis-parallel rectangles in dimensions three and higher (Folklore)
  • Komlos conjecture
  • The three permutations problem (Beck)
  • Homogeneous arithmetic progressions (Erdos, $500)

[edit] Applications

  • Numerical Integration: Monte Carlo methods in high dimensions.
  • Computational Geometry: Divide and conquer algorithms.
  • Image Processing: Halftoning

[edit] References

  • Irregularities of Distribution (Beck & Chen)
  • Geometric Discrepancy (Matousek)
  • The Discrepancy Method (Chazelle)