English

A Refinement of the McCreight-Meyer Union Theorem

Computational Complexity 2024-06-14 v1

Abstract

Using properties of Blum complexity measures and certain complexity class operators, we exhibit a total computable and non-decreasing function tpolyt_{\mathsf{poly}} such that for all kk, ΣkP=ΣkTIME(tpoly)\Sigma_k\mathsf{P} = \Sigma_k\mathsf{TIME}(t_{\mathsf{poly}}), BPP=BPTIME(tpoly)\mathsf{BPP} = \mathsf{BPTIME}(t_{\mathsf{poly}}), RP=RTIME(tpoly)\mathsf{RP} = \mathsf{RTIME}(t_{\mathsf{poly}}), UP=UTIME(tpoly)\mathsf{UP} = \mathsf{UTIME}(t_{\mathsf{poly}}), PP=PTIME(tpoly)\mathsf{PP} = \mathsf{PTIME}(t_{\mathsf{poly}}), ModkP=ModkTIME(tpoly)\mathsf{Mod}_k\mathsf{P} = \mathsf{Mod}_k\mathsf{TIME}(t_{\mathsf{poly}}), PSPACE=DSPACE(tpoly)\mathsf{PSPACE} = \mathsf{DSPACE}(t_{\mathsf{poly}}), and so forth. A similar statement holds for any collection of language classes, provided that each class is definable by applying a certain complexity class operator to some Blum complexity class.

Keywords

Cite

@article{arxiv.2406.08600,
  title  = {A Refinement of the McCreight-Meyer Union Theorem},
  author = {Matthew Fox and Chaitanya Karamchedu},
  journal= {arXiv preprint arXiv:2406.08600},
  year   = {2024}
}

Comments

11 pages

R2 v1 2026-06-28T17:03:43.707Z