Hierarchies of Inefficient Kernelizability

Danny Hermelin, Stefan Kratsch, Karolina Sołtys, Magnus Wahlström, Xi Wu

Research output: Working paper/PreprintPreprint


The framework of Bodlaender et al. (ICALP 2008) and Fortnow and Santhanam (STOC 2008) allows us to exclude the existence of polynomial kernels for a range of problems under reasonable complexity-theoretical assumptions. However, there are also some issues that are not addressed by this framework, including the existence of Turing kernels such as the "kernelization" of Leaf Out Branching(k) into a disjunction over n instances of size poly(k). Observing that Turing kernels are preserved by polynomial parametric transformations, we define a kernelization hardness hierarchy, akin to the M- and W-hierarchy of ordinary parameterized complexity, by the PPT-closure of problems that seem likely to be fundamentally hard for efficient Turing kernelization. We find that several previously considered problems are complete for our fundamental hardness class, including Min Ones d-SAT(k), Binary NDTM Halting(k), Connected Vertex Cover(k), and Clique(k log n), the clique problem parameterized by k log n.
Original languageEnglish
StatePublished - 2011

Publication series

NamearXiv PrePrint,


Dive into the research topics of 'Hierarchies of Inefficient Kernelizability'. Together they form a unique fingerprint.

Cite this