• DocumentCode
    2931640
  • Title

    Hyper-polynomial hierarchies and the NP-jump

  • Author

    Fenner, Stephen ; Homer, Steven ; Pruim, Randall ; Schaefer, Marcus

  • Author_Institution
    Dept. of Comput. Sci., Univ. of Southern Maine, Portland, ME, USA
  • fYear
    1997
  • fDate
    24-27 Jun 1997
  • Firstpage
    102
  • Lastpage
    110
  • Abstract
    Assuming that the polynomial hierarchy (PH) does not collapse, we show the existence of ascending sequences of ptime Turing degrees of length ω1CK all of which are in PSPACE and uniformly hard for PH, such that successors are NP-jumps of their predecessors. This is analogous to the hyperarithmetic hierarchy which is defined similarly but with the (recursive) Turing degrees. The lack of uniform least upper bounds for ascending sequences of ptime degrees causes (the limit levels of) our hyper-polynomial hierarchy to be inherently non-canonical. This problem is investigated in depth, and various possible structures for hyper-polynomial hierarchies are explicated, as are properties of the NP-jump operator on the languages which are in PSPACE but not in PH
  • Keywords
    Turing machines; computational complexity; NP-jump; PSPACE; ascending sequences; hyper-polynomial hierarchies; ptime Turing degrees; uniform least upper bounds; Arithmetic; Complexity theory; Computer science; Educational institutions; Logic; Polynomials; Upper bound;
  • fLanguage
    English
  • Publisher
    ieee
  • Conference_Titel
    Computational Complexity, 1997. Proceedings., Twelfth Annual IEEE Conference on (Formerly: Structure in Complexity Theory Conference)
  • Conference_Location
    Ulm
  • ISSN
    1093-0159
  • Print_ISBN
    0-8186-7907-7
  • Type

    conf

  • DOI
    10.1109/CCC.1997.612305
  • Filename
    612305