Weights of Exact Threshold Functions

  • László Babai
  • Kristoffer Arnsfelt Hansen
  • Vladimir V. Podolskii
  • Xiaoming Sun
Part of the Lecture Notes in Computer Science book series (LNCS, volume 6281)


We consider Boolean exact threshold functions defined by linear equations, and in general degree d polynomials. We give upper and lower bounds on the maximum magnitude (absolute value) of the coefficients required to represent such functions. These bounds are very close and in the linear case in particular they are almost matching. The quantity is the same as the maximum magnitude of integer coefficients of linear equations required to express every possible intersection of a hyperplane in R n and the Boolean cube {0,1} n , or in the general case intersections of hypersurfaces of degree d in R n and the Boolean cube {0,1} n . In the process we construct new families of ill-conditioned matrices. We further stratify the problem (in the linear case) in terms of the dimension k of the affine subspace spanned by the solutions, and give upper and lower bounds in this case as well. Our bounds here in terms of k leave a substantial gap, a challenge for future work.


Boolean Function Linear Case Threshold Function Integer Weight Symmetric Boolean Function 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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© Springer-Verlag Berlin Heidelberg 2010

Authors and Affiliations

  • László Babai
    • 1
  • Kristoffer Arnsfelt Hansen
    • 2
  • Vladimir V. Podolskii
    • 3
  • Xiaoming Sun
    • 4
  1. 1.The University of Chicago 
  2. 2.Aarhus University 
  3. 3.Steklov Mathematical Institute 
  4. 4.ITCSTsinghua University 

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