The Exponential Time Hypothesis and the Parameterized Clique Problem

  • Yijia Chen
  • Kord Eickmeyer
  • Jörg Flum
Part of the Lecture Notes in Computer Science book series (LNCS, volume 7535)


In parameterized complexity there are three natural definitions of fixed-parameter tractability called strongly uniform, weakly uniform and nonuniform fpt. Similarly, there are three notions of subexponential time, yielding three flavours of the exponential time hypothesis (ETH) stating that 3Sat is not solvable in subexponential time. It is known that ETH implies that p-Clique is not fixed-parameter tractable if both are taken to be strongly uniform or both are taken to be uniform, and we extend this to the nonuniform case. We also show that even the containment of weakly uniform subexponential time in nonuniform subexponential time is strict. Furthermore, we deduce from nonuniform ETH that no single exponent d allows for arbitrarily good fpt-approximations of clique.


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Copyright information

© Springer-Verlag Berlin Heidelberg 2012

Authors and Affiliations

  • Yijia Chen
    • 1
  • Kord Eickmeyer
    • 2
  • Jörg Flum
    • 3
  1. 1.Department of Computer ScienceShanghai Jiaotong UniversityChina
  2. 2.National Institute of InformaticsTokyoJapan
  3. 3.Mathematisches InstitutAlbert-Ludwigs-Universität FreiburgGermany

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