Dichotomy for Holant problems of Boolean domain

  • Authors:
  • Jin-Yi Cai;Pinyan Lu;Mingji Xia

  • Affiliations:
  • University of Wisconsin-Madison and Beijing University;Microsoft Research Asia;Chinese Academy of Sciences

  • Venue:
  • Proceedings of the twenty-second annual ACM-SIAM symposium on Discrete Algorithms
  • Year:
  • 2011

Quantified Score

Hi-index 0.00

Visualization

Abstract

Holant problems are a general framework to study counting problems. Both counting Constraint Satisfaction Problems (#CSP) and graph homomorphisms are special cases. We prove a complexity dichotomy theorem for Holant*(F), where F is a set of constraint functions on Boolean variables and output complex values. The constraint functions need not be symmetric functions. We identify four classes of problems which are polynomial time computable; all other problems are proved to be #P-hard. The main proof technique and indeed the formulation of the theorem use holographic algorithms and reductions. By considering these counting problems over the complex domain, we discover surprising new tractable classes, which are associated with isotropic vectors, i.e., a (non-zero) vector whose inner product with itself is zero.