English

Computational Hardness of Enumerating Satisfying Spin-Assignments in Triangulations

Computational Complexity 2011-07-20 v1

Abstract

Satisfying spin-assignments in triangulations of a surface are states of minimum energy of the antiferromagnetic Ising model on triangulations which correspond (via geometric duality) to perfect matchings in cubic bridgeless graphs. In this work we show that it is NP-complete to decide whether or not a surface triangulation admits a satisfying spin-assignment, and that it is #P-complete to determine the number of such assignments. Both results are derived via an elaborate (and atypical) reduction that maps a Boolean formula in 3-conjunctive normal form into a triangulation of an orientable closed surface.

Keywords

Cite

@article{arxiv.1107.3767,
  title  = {Computational Hardness of Enumerating Satisfying Spin-Assignments in Triangulations},
  author = {Andrea Jiménez and Marcos Kiwi},
  journal= {arXiv preprint arXiv:1107.3767},
  year   = {2011}
}

Comments

20 pages,25 figures