Exponential Time Complexity of the Permanent and the Tutte Polynomial

Research output: Contribution to journalArticle


We show conditional lower bounds for well-studied #P-hard problems: -The number of satisfying assignments of a 2-CNF formula with n variables cannot be computed in time exp(o(n)), and the same is true for computing the number of all independent sets in an n-vertex graph. -The permanent of an n x n matrix with entries 0 and 1 cannot be computed in time exp(o(n)). -The Tutte polynomial of an n-vertex multigraph cannot be computed in time exp(o(n)) at most evaluation points (x, y) in the case of multigraphs, and it cannot be computed in time exp(o(n/poly log n)) in the case of simple graphs. Our lower bounds are relative to (variants of) the Exponential Time Hypothesis (ETH), which says that the satisfiability of n-variable 3-CNF formulas cannot be decided in time exp(o(n)). We relax this hypothesis by introducing its counting version #ETH; namely, that the satisfying assignments cannot be counted in time exp(o(n)). In order to use #ETH for our lower bounds, we transfer the sparsification lemma for d-CNF formulas to the counting setting.


External organisations
  • Uppsala University
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Computer Science


  • Theory, Algorithms, Computational complexity, counting problems, Tutte, polynomial, permanent, exponential time hypothesis
Original languageEnglish
Pages (from-to)21
JournalACM Transactions on Algorithms
Issue number4
Publication statusPublished - 2014
Publication categoryResearch